Browsing by Author "Levan, Justine"

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Genes Regulated by HPV 16 E6 and High Expression of NFX1-123 in Cervical Cancers
    (Dove Press, 2020-06-26) Chintala, Sreenivasulu; Levan, Justine; Robinson, Kristin; Quist, Kevin; Katzenellenbogen, Rachel A.; Pediatrics, School of Medicine
    Purpose High-risk human papillomaviruses (HR HPV) cause cervical cancer, and in these cancers, HPV type 16 is the most common HR type. The HR viral oncogenes E6 and E7 partner with cellular proteins to drive cancer and modulate immune pathways; previously, we demonstrated in keratinocytes that HPV 16 E6 and high expression of the endogenous host protein partner NFX1-123 led to the increased expression of multiple genes, including Notch1, secretory leukocyte peptidase inhibitor (SLPI), and retinoic acid early transcript 1G (RAET1G). The present study was conducted to determine if NFX1-123 was highly expressed in cervical cancer and if genes increased by NFX1-123 and 16E6 in keratinocytes were also increased in cervical cancers. Materials and Methods The Cancer Genome Atlas (TCGA) database and The Human Protein Atlas database were used to compare relative mRNA and protein gene expression, respectively, in the normal cervix and cervical cancers. Formalin-fixed paraffin-embedded (FFPE) normal cervix and HPV 16 positive cervical cancer samples were analyzed for relative protein expression by immunohistochemical staining. Protein expression of a subset of regulated genes was quantified by Western blot of HPV positive and negative cell lines. Results Immunohistochemical staining of HPV 16 positive cervical dysplasias and cancers revealed high NFX1-123, Ki67, and Notch1 expression. NFX1 and NFX1L1 mRNA levels were increased in cervical cancers compared to normal cervix in the TCGA database. Fourteen genes previously identified as upregulated in keratinocytes with 16E6 and overexpressed NFX1-123 also had high mRNA expression and selected genes had high protein expression in cervical cancers and cell lines. Conclusion In cervical cancer, NFX1-123 is highly expressed, and 16E6 and NFX1-123 together alter the expression of a wide set of genes. The involvement of these genes in cell proliferation, differentiation, invasion, and metastasis provides further insight into potential ways that HR HPVs promote cancer initiation and maintenance.
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    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.