Utility of TTMV-HPV DNA in resolving indeterminate findings during oropharyngeal cancer surveillance.

OBJECTIVES: Clinical and imaging examinations frequently have indeterminate results during cancer surveillance, which can lead to overtreatment and cause psychological and financial harm to the patient. This study addresses the critical need to enhance diagnostic precision and decision-making in the management of HPV-associated oropharyngeal cancer. This study evaluated the utility of tumor tissue-modified viral (TTMV)-HPV DNA to resolve indeterminate disease status following definitive treatment for HPV-associated oropharyngeal cancer. MATERIALS AND METHODS: In this retrospective cohort, patients treated for HPV-associated oropharyngeal cancer at eight U.S. institutions and who received one or more TTMV-HPV DNA tests during post-treatment surveillance between February 2020 and January 2022 were included. RESULTS: Among 543 patients, 210 patients (38.7%; 210/543) experienced one or more clinically indeterminate findings (CIFs) during surveillance, with 503 CIFs recorded. Of those patients with an "indeterminate" disease status at a point during surveillance, 79 were associated with contemporaneous TTMV-HPV DNA testing. TTMV-HPV DNA testing demonstrated high accuracy (97.5%; 77/79) in correctly determining recurrence status. Patients whose disease status was "indeterminate" at the time of a positive TTMV-HPV DNA test were clinically confirmed to recur faster than those whose disease status was "no evidence of disease." Only 3% of patients (17/543) experienced indeterminate TTMV-HPV DNA tests during surveillance. Discordance between TTMV-HPV DNA tests and clinical results was minimal, with only 0.6% (3/543) of patients showing positive tests without recurrence. CONCLUSION: Our findings support the utility of circulating TTMV-HPV DNA in resolving indeterminate disease status and informing the subsequent clinical course.

The Role of Extracellular Vesicles in Mediating Resistance to Anticancer Therapies.

Although advances in targeted therapies have driven great progress in cancer treatment and outcomes, drug resistance remains a major obstacle to improving patient survival. Several mechanisms are involved in developing resistance to both conventional chemotherapy and molecularly targeted therapies, including drug efflux, secondary mutations, compensatory genetic alterations occurring upstream or downstream of a drug target, oncogenic bypass, drug activation and inactivation, and DNA damage repair. Extracellular vesicles (EVs) are membrane-bound lipid bilayer vesicles that are involved in cell-cell communication and regulating biological processes. EVs derived from cancer cells play critical roles in tumor progression, metastasis, and drug resistance by delivering protein and genetic material to cells of the tumor microenvironment. Understanding the biochemical and genetic mechanisms underlying drug resistance will aid in the development of new therapeutic strategies. Herein, we review the role of EVs as mediators of drug resistance in the context of cancer.

The Role of Cancer-Associated Fibroblasts and Extracellular Vesicles in Tumorigenesis.

Extracellular vesicles (EVs) play a key role in the communication between cancer cells and stromal components of the tumor microenvironment (TME). In this context, cancer cell-derived EVs can regulate the activation of a CAF phenotype in TME cells, which can be mediated by several EV cargos (e.g., miRNA, proteins, mRNA and lncRNAs). On the other hand, CAF-derived EVs can mediate several processes during tumorigenesis, including tumor growth, invasion, metastasis, and therapy resistance. This review aimed to discuss the molecular aspects of EV-based cross-talk between CAFs and cancer cells during tumorigenesis, in addition to assessing the roles of EV cargo in therapy resistance and pre-metastatic niche formation.

Sphingomyelin phosphodiesterase 3 methylation and silencing in oral squamous cell carcinoma results in increased migration and invasion and altered stress response.

Neutral sphingomyelinase 2 (nSMase2), the product of the sphingomyelin phosphodiesterase 3 (SMPD3) gene, catalyzes the hydrolysis of sphingomyelin to ceramide. Ceramide acts on various signaling pathways to influence cell proliferation, survival, and stress response. Altered levels of sphingolipids and ceramides have been reported in various cancer types, including oral squamous cell carcinoma (OSCC). OSCC patients exhibit a poor 5-year survival rate of 50%, a figure that has remained stagnant for decades. To overcome this requires a better understanding of the molecular events driving this disease. The molecular analysis of the oral cavity reported here has identified the SMPD3 promoter region as a site of frequent hypermethylation and downregulation in pre-malignant and malignant tissues as compared with healthy control tissues. While lentivirus-induced overexpression of SMPD3 in cell models of oral dysplasia and OSCC did not significantly alter proliferation, it did decrease migration and invasion and increased resistance to the epidermal growth factor receptor (EGFR) inhibitor erlotinib. These results suggest that SMPD3 downregulation is a common event in OSCC progression and may promote the spread of tumor cells.

Extracellular vesicle secretion of miR-142-3p from lung adenocarcinoma cells induces tumor promoting changes in the stroma through cell-cell communication.

Extracellular vesicles (EVs) are mediators of communication between cancer cells and the surrounding tumor microenvironment. EV content is able to influence key tumorigenic changes including invasion, metastasis, and inducing pro-tumor changes in the stroma. MiR-142-3p is a known tumor suppressor in LAC and was recently shown to be enriched within LAC EVs, indicating its potential as a key signaling miRNA. Our research demonstrates the role EV associated miR-142-3p plays when transferred from LAC cells to both endothelial and fibroblast cells. We demonstrate that transfer of miR-142-3p in LAC EVs to endothelial cells promotes angiogenesis through inhibition of TGFßR1. Additionally, we show EV associated miR-142-3p promotes the cancer-associated fibroblast phenotype in lung fibroblast cells which we show is independent of TGFß signaling. These findings suggest that miR-142-3p within LAC EVs can be transferred from LAC cells to both endothelial and fibroblast cells to promote tumor associated changes.

The Role of Extracellular Vesicles in Cancer: Cargo, Function, and Therapeutic Implications.

Extracellular vesicles (EVs) are a heterogeneous collection of membrane-bound structures that play key roles in intercellular communication. EVs are potent regulators of tumorigenesis and function largely via the shuttling of cargo molecules (RNA, DNA, protein, etc.) among cancer cells and the cells of the tumor stroma. EV-based crosstalk can promote proliferation, shape the tumor microenvironment, enhance metastasis, and allow tumor cells to evade immune destruction. In many cases these functions have been linked to the presence of specific cargo molecules. Herein we will review various types of EV cargo molecule and their functional impacts in the context of oncology.

Identification of Malignancy-Associated Changes in Histologically Normal Tumor-Adjacent Epithelium of Patients with HPV-Positive Oropharyngeal Cancer.

The incidence of HPV-positive oropharyngeal cancer (HPV+ OPC) is increasing, thus presenting new challenges for disease detection and management. Noninvasive methods involving brush biopsies of diseased tissues were recently reported as insufficient for tumor detection in HPV+ OPC patients, likely due to differences between the site of tumor initiation at the base of involuted crypts and the site of brush biopsy at the crypt surface. We hypothesized that histologically normal surface epithelial cells in the oropharynx contain changes in nuclear morphology that arise due to tumor proximity. We analyzed the nuclear phenotype of matched tumor, tumor-adjacent normal, and contralateral normal tissues from biopsies of nine HPV+ OPC patients. Measurements of 89 nuclear features were used to train a random forest-based classifier to discriminate between normal and tumor nuclei. We then extracted voting scores from the trained classifier, which classify nuclei on a continuous scale from zero ("normal-like") to one ("tumor-like"). In each case, the average score of the adjacent normal nuclei was intermediate between the tumor and contralateral normal nuclei. These results provide evidence for the existence of phenotypic changes in histologically normal, tumor-adjacent surface epithelial cells, which could be used as brush biopsy-based biomarkers for HPV+ OPC detection.

Selective secretion of microRNAs from lung cancer cells via extracellular vesicles promotes CAMK1D-mediated tube formation in endothelial cells.

Extracellular vesicles (EVs) are key signaling mediators between cancer cells and their supporting stroma, and regulate critical processes such as invasion, metastases, and angiogenesis. We have identified a subset of miRNAs (miR-142-3p, miR-143-3p, miR-145-5p, miR-150-5p, miR-223-3p, miR-451a, miR-486-5p, miR-605-5p) that are enriched in lung adenocarcinoma extracellular vesicles compared to the donor cells from which they were derived. Two well-known tumor suppressors, miR-143-3p and miR-145-5p, were also enriched in serum samples collected during surgery from blood vessels draining directly from lung adenocarcinoma tumor beds. Recently, both miRNAs were found to promote neoangiogenesis in endothelial cells in mouse models of lung adenocarcinoma through targeting of CAMK1D, an inhibitory kinase that can impair angiogenesis when over-expressed. We show that the transfer of miR-143-3p and miR-145-5p within extracellular vesicles from lung adenocarcinoma cells to endothelial cells reduces the levels of CAMK1D and increases tube formation by endothelial cells. This finding suggests that transfer of miRNAs within extracellular vesicles is a method of communication between cancer and endothelial cells which promotes angiogenesis while simultaneously removing tumor suppressive miRNAs within the tumor cells, thus driving tumorigenesis.

Selective extracellular vesicle exclusion of miR-142-3p by oral cancer cells promotes both internal and extracellular malignant phenotypes.

Packaging of small molecular factors, including miRNAs, into small extracellular vesicles (SEVs) may contribute to malignant phenotypes and facilitate communication between cancer cells and tumor stroma. The process by which some miRNAs are enclosed in SEVs is selective rather than indiscriminate, with selection in part governed by specific miRNA sequences. Herein, we describe the selective packaging and removal via SEVs of four miRNAs (miR-142-3p, miR-150-5p, miR-451a, and miR-223-3p) in a panel of oral dysplasia and oral squamous cell carcinoma cell lines. Inhibition of exosome export protein Rab27A increased intracellular concentration of these miRNA candidates and prevented their exclusion via SEVs. Increased intracellular miR-142-3p specifically was found to target TGFBR1, causing a decrease in TGFBR1 expression in donor cells and a reduction of malignant features such as growth and colony formation. Conversely, increased excretion of miR-142-3p via donor cell SEVs and uptake by recipient endothelial cells was found to reduce TGFBR1 activity and cause tumor-promoting changes in these cells in vitro and in vivo.

Vascular endothelial growth factor signaling affects both angiogenesis and osteogenesis during the development of scleral ossicles.

Intramembranous ossification is a complex multi-step process which relies on extensive interactions among bone cells and surrounding tissues. The embryonic vasculature is essential in regulating endochondral ossification; however, its role during intramembranous ossification remains poorly understood, and in vivo studies are lacking. Previous research from our lab on the development of the intramembranous scleral ossicles has demonstrated an intriguing pattern of vascular development in which the areas of future osteogenesis remain avascular until after bone induction has occurred. Such avascular zones are located directly beneath each of the conjunctival papillae, epithelial structures which provide osteogenic signals to the underlying mesenchyme. Here we provide a high-resolution map of the developing vasculature from the time of ossicle induction to mineralization using a novel technique. We show that vegfa is expressed by the papillae and nearby mesenchymal tissue throughout HH 34-37, when vascular growth is taking place, and is down-regulated thereafter. Localized inhibition of Vegf results in expansion of the avascular zone surrounding the implanted papilla and mispatterning of the scleral ossicles. These results demonstrate that Vegf signaling could provide important insights into the complex relationship between bone and vasculature during intramembranous bone development.