ctDNA predicts recurrence and survival in stage I and II HPV-associated head and neck cancer patients treated with surgery.

Human papillomavirus-associated oropharyngeal squamous cell carcinomas (HPV+OPSCC) release circulating tumor HPV DNA (ctHPVDNA) into the blood which we, and others, have shown is an accurate real-time biomarker of disease status. In a prior prospective observational trial of 34 patients with AJCC 8 stage I-II HPV+OPSCC treated with surgery, we reported that ctHPVDNA was rapidly cleared within hours of surgery in patients who underwent complete cancer extirpation, yet remained elevated in those with macroscopic residual disease. The primary outcomes of this study were to assess 2-year OS and RFS between patients with and without molecular residual disease (MRD) following completion of treatment in this prospective cohort.

Assessing the feasibility of a multimodal liquid biopsy for the diagnosis of HPV-associated oropharyngeal squamous cell carcinoma.

Objectives: In this feasibility study, we explored the combined use of circulating tumor human papillomavirus (HPV) DNA (ctHPVDNA) and HPV serology as diagnostic tests for HPV-associated oropharyngeal squamous cell carcinoma (OPSCC).

Methods: Among patients with research-banked serum or plasma at diagnosis, IgG antibodies to oncoproteins from HPV types 16, 18, 31, 33, 35, 45, 52, and 58 were detected with multiplex serology. Positivity for HPV 16 was defined based on detection of combinations of anti-E6, E1, E2, and E7 and for other high-risk types on detection of anti-E6 and anti-E7.

Double trouble: Synchronous and metachronous primaries confound ctHPVDNA monitoring.

Background: Human papillomavirus-associated head and neck squamous cell carcinoma (HPV + HNSCC) occurs in the oropharynx (HPV + OPSCC), sinonasal cavity (HPV + SNSCC), and nasopharynx (HPV + NPC). Circulating tumor HPV DNA (ctHPVDNA) is an accurate tool for diagnosis, treatment monitoring, and recurrence detection. An emerging challenge with ctHPVDNA is that ~7.

Interaction with TopBP1 Is Required for Human Papillomavirus 16 E2 Plasmid Segregation/Retention Function during Mitosis.

Human papillomavirus 16 (HPV16) E2 is a DNA-binding protein that regulates transcription, replication and potentially, segregation of the HPV16 genome during the viral life cycle. In the segregation model, E2 simultaneously binds to viral and host chromatin, acting as a bridge to ensure that viral genomes reside in daughter nuclei following cell division. The host chromatin receptor for E2 mediating this function is unknown.

CK2 Phosphorylation of Human Papillomavirus 16 E2 on Serine 23 Promotes Interaction with TopBP1 and Is Critical for E2 Interaction with Mitotic Chromatin and the Viral Life Cycle.

During the human papillomavirus 16 (HPV16) life cycle, the E2 protein interacts with host factors to regulate viral transcription, replication, and genome segregation/retention. Our understanding of host partner proteins and their roles in E2 functions remains incomplete. Here we demonstrate that CK2 phosphorylation of E2 on serine 23 promotes interaction with TopBP1 and and that E2 is phosphorylated on this residue during the HPV16 life cycle.

Human Papillomavirus 16 (HPV16) E2 Repression of TWIST1 Transcription Is a Potential Mediator of HPV16 Cancer Outcomes.

Human papillomaviruses (HPVs) are causative agents in around 5% of all cancers, including cervical and oropharyngeal. A feature of HPV cancers is their better clinical outcome compared with non-HPV anatomical counterparts. In turn, the presence of E2 predicts a better clinical outcome in HPV-positive cancers; the reason(s) for the better outcome of E2-positive patients is not fully understood.

Using a Human Papillomavirus Model to Study DNA Replication and Repair of Wild Type and Damaged DNA Templates in Mammalian Cells.

Human papillomaviruses have 8kbp DNA episomal genomes that replicate autonomously from host DNA. During initial infection, the virus increases its copy number to 20-50 copies per cell, causing torsional stress on the replicating DNA. This activates the DNA damage response (DDR) and HPV replicates its genome, at least in part, using homologous recombination.

Werner Syndrome Protein (WRN) Regulates Cell Proliferation and the Human Papillomavirus 16 Life Cycle during Epithelial Differentiation.

Human papillomaviruses recruit a host of DNA damage response factors to their viral genome to facilitate homologous recombination replication in association with the viral replication factors E1 and E2. We previously demonstrated that SIRT1 deacetylation of WRN promotes recruitment of WRN to E1-E2 replicating DNA and that WRN regulates both the levels and fidelity of E1-E2 replication. The deacetylation of WRN by SIRT1 results in an active protein able to complex with replicating DNA, but a protein that is less stable.

Activating the DNA Damage Response and Suppressing Innate Immunity: Human Papillomaviruses Walk the Line.

Activation of the DNA damage response (DDR) by external agents can result in DNA fragments entering the cytoplasm and activating innate immune signaling pathways, including the stimulator of interferon genes (STING) pathway. The consequences of this activation can result in alterations in the cell cycle including the induction of cellular senescence, as well as boost the adaptive immune response following interferon production. Human papillomaviruses (HPV) are the causative agents in a host of human cancers including cervical and oropharyngeal; HPV are responsible for around 5% of all cancers.

Human Papillomavirus 16 E6 and E7 Synergistically Repress Innate Immune Gene Transcription.

Human papillomaviruses (HPV) are causative agents in 5% of all cancers, including the majority of anogenital and oropharyngeal cancers. Downregulation of innate immune genes (IIGs) by HPV to promote the viral life cycle is well documented; E6 and E7 are known repressors of these genes. More recently, we demonstrated that E2 could also repress IIGs.

Werner Helicase Control of Human Papillomavirus 16 E1-E2 DNA Replication Is Regulated by SIRT1 Deacetylation.

Human papillomaviruses (HPV) are double-stranded DNA viruses causative in a host of human diseases, including several cancers. Following infection, two viral proteins, E1 and E2, activate viral replication in association with cellular factors and stimulate the DNA damage response (DDR) during the replication process. E1-E2 uses homologous recombination (HR) to facilitate DNA replication, but an understanding of host factors involved in this process remains incomplete.

Why Human Papillomaviruses Activate the DNA Damage Response (DDR) and How Cellular and Viral Replication Persists in the Presence of DDR Signaling.

Human papillomaviruses (HPV) require the activation of the DNA damage response (DDR) in order to undergo a successful life cycle. This activation presents a challenge for the virus and the infected cell: how does viral and host replication proceed in the presence of a DDR that ordinarily arrests replication; and how do HPV16 infected cells retain the ability to proliferate in the presence of a DDR that ordinarily arrests the cell cycle? This raises a further question: why do HPV activate the DDR? The answers to these questions are only partially understood; a full understanding could identify novel therapeutic strategies to target HPV cancers. Here, we propose that the rapid replication of an 8 kb double stranded circular genome during infection creates aberrant DNA structures that attract and activate DDR proteins.

Calcein represses human papillomavirus 16 E1-E2 mediated DNA replication via blocking their binding to the viral origin of replication.

Human papillomaviruses are causative agents in several human diseases ranging from genital warts to ano-genital and oropharyngeal cancers. Currently only symptoms of HPV induced disease are treated; there are no antivirals available that directly target the viral life cycle. Previously, we determined that the cellular protein TopBP1 interacts with the HPV16 replication/transcription factor E2.

The Deacetylase SIRT1 Regulates the Replication Properties of Human Papillomavirus 16 E1 and E2.

Human papillomaviruses (HPV) replicate their genomes in differentiating epithelium using the viral proteins E1 and E2 in association with host proteins. While the roles of E1 and E2 in this process are understood, the host factors involved and how they interact with and regulate E1-E2 are not. Our previous work identified the host replication and repair factor TopBP1 as an E2 partner protein essential for optimal E1-E2 replication and for the viral life cycle.

Chk1 inhibitor synergizes quinacrine mediated apoptosis in breast cancer cells by compromising the base excision repair cascade.

Quinacrine (QC) causes apoptosis in breast cancer cells by induction of DNA damage, arrest of cells in S-phase, and by topoisomerase inhibition. Here, we show that QC-mediated apoptosis is not only due to increased DNA damage but also by compromising cell cycle checkpoints and base excision repair (BER) capacity in breast cancer cells. QC decreased CHK1, CDKs (CDC2, MDM2, CDC6), cyclins (B1, E1) and CDC25-A in a dose dependent manner.

Nanoquinacrine induced apoptosis in cervical cancer stem cells through the inhibition of hedgehog-GLI1 cascade: Role of GLI-1.

To improve the pharmacokinetics and to study the anti-cervical cancer and anti-stem cells (CSCs) mechanism of Quinacrine (QC), a spherical nano particle of QC (i.e. NQC) was prepared and characterized.

Enhancement of Cytotoxicity and Inhibition of Angiogenesis in Oral Cancer Stem Cells by a Hybrid Nanoparticle of Bioactive Quinacrine and Silver: Implication of Base Excision Repair Cascade.

A poly(lactic-co-glycolic acid) (PLGA)-based uniform (50-100 nm) hybrid nanoparticle (QAgNP) with positive zeta potential (0.52 ± 0.09 mV) was prepared by single emulsion solvent evaporation method with bioactive small molecule quinacrine (QC) in organic phase and silver (Ag) in aqueous phase.

Resveratrol and curcumin synergistically induces apoptosis in cigarette smoke condensate transformed breast epithelial cells through a p21(Waf1/Cip1) mediated inhibition of Hh-Gli signaling.

Combination therapy using two or more small molecule inhibitors of aberrant signaling cascade in aggressive breast cancers is a promising therapeutic strategy over traditional monotherapeutic approaches. Here, we have studied the synergistic mechanism of resveratrol and curcumin induced apoptosis using in vitro (cigarette smoke condensate mediated transformed breast epithelial cell, MCF-10A-Tr) and in vivo (tumor xenograft mice) model system. Resveratrol exposure increased the intracellular uptake of curcumin in a dose dependent manner and caused apoptosis in MCF-10A-Tr cells.

NECTIN-4 increased the 5-FU resistance in colon cancer cells by inducing the PI3K-AKT cascade.

Purpose: 5-Fluorouracil is the most commonly used drug for the treatment of colon cancer, yet clinical resistance to this drug is frequently observed in patients making this drug ineffective. Thus, identification of gene responsible for 5-FU resistance is of utmost importance.

Methods: Cellular cytotoxicity and expressions of different protein markers in colon cancer cells were measured by MTT assay and Western blotting, respectively.