An enhanced triple fluorescence flow-cytometry-based assay shows differential activation of the Notch signaling pathway by human papillomavirus E6 proteins

In vitro antineoplastic effects of MK0752 in HPV-positive head and neck squamous cell carcinoma

PURPOSE

Gamma-secretase inhibitor MK0752 has shown a high therapeutic potential in different solid malignant tumors. Up to now, its antineoplastic effects were not investigated in head and neck squamous cell carcinoma (HNSCC) and particularly in human-papillomavirus (HPV)-positive tumors.

METHODS

We conducted cytotoxic, migration, and clonogenic assays in two HPV-negative HNSCC cell lines (Cal27 and FaDu) and one HPV-positive cell line (SCC154). Furthermore, in order to assess the pro-apoptotic effects of MK0752, a Caspase 3/7 Glo assay was performed.

RESULTS

Our experiments revealed antineoplastic effects of MK0752 in all three cell lines. Strong cytotoxic and antimigratory potential was shown in all cell lines, with strongest effects observed in the HPV-positive cell line. Meanwhile, anticlonogenic effects were only shown in Cal27 and SCC154. Most importantly, MK0752 induced apoptosis solely in HPV-positive SCC154.

CONCLUSIONS

Our novel findings indicate a therapeutic potential of MK0752 in HPV-positive HNSCC. Indeed, further investigation is needed for validation of our results and for the assessment of the mechanistic background.

Human papillomavirus associated cervical lesion: pathogenesis and therapeutic interventions

Human papillomavirus (HPV) is the most prevalent sexually transmitted virus globally. Persistent high-risk HPV infection can result in cervical precancerous lesions and cervical cancer, with 70% of cervical cancer cases associated with high-risk types HPV16 and 18. HPV infection imposes a significant financial and psychological burden. Therefore, studying methods to eradicate HPV infection and halt the progression of precancerous lesions remains crucial. This review comprehensively explores the mechanisms underlying HPV-related cervical lesions, including the viral life cycle, immune factors, epithelial cell malignant transformation, and host and environmental contributing factors. Additionally, we provide a comprehensive overview of treatment methods for HPV-related cervical precancerous lesions and cervical cancer. Our focus is on immunotherapy, encompassing HPV therapeutic vaccines, immune checkpoint inhibitors, and advanced adoptive T cell therapy. Furthermore, we summarize the commonly employed drugs and other nonsurgical treatments currently utilized in clinical practice for managing HPV infection and associated cervical lesions. Gene editing technology is currently undergoing clinical research and, although not yet employed officially in clinical treatment of cervical lesions, numerous preclinical studies have substantiated its efficacy. Therefore, it holds promise as a precise treatment strategy for HPV-related cervical lesions.

Cottontail rabbit papillomavirus E6 proteins: Interaction with MAML1 and modulation of the Notch signaling pathway

Animal models are necessary to study how cutaneous human papillomaviruses (HPVs) are associated with carcinogenesis. The cottontail rabbit papillomavirus (CRPV) induces papilloma in the -cutaneous skin of rabbits and serves as an established animal model for HPVlinked carcinogenesis where viral E6 proteins play crucial roles. Several studies have reported the dysregulation of the Notch signaling pathway by cutaneous beta HPV, bovine PV and mouse PV E6 via their association with Mastermind-like 1 protein (MAML1), thus interfering with cell proliferation and differentiation. However, the CRPV E6 gene encodes an elongated E6 protein (long E6, LE6) and an N-terminally truncated product (short E6, SE6) making it unique from other E6 proteins. Here, we describe the interaction between both CRPV E6 proteins and MAML1 and their ability to downregulate the Notch signaling pathway which could be a way CRPV infection induces carcinogenesis similar to beta HPV.