Care in the time of coronavirus: Ethical considerations in head and neck oncology.

As COVID-19 continues to challenge the practice of head and neck oncology, clinicians are forced to make new decisions in the setting of the pandemic that impact the safety of their patients, their institutions, and themselves. The difficulty inherent in these decisions is compounded by potentially serious ramifications to the welfare of patients and health-care staff, amid a scarcity of data on which to base informed choices. This paper explores the risks of COVID-19 incurred while striving to uphold the standard of care in head and neck oncology. The ethical problems are assessed from the perspective of the patient with cancer, health-care provider, and other patients within the health-care system. While no single management algorithm for head and neck cancer can be universally implemented, a detailed examination of these issues is necessary to formulate ethically sound treatment strategies.

Head and neck oncology during the COVID-19 pandemic: Reconsidering traditional treatment paradigms in light of new surgical and other multilevel risks.

The COVID-19 pandemic demands reassessment of head and neck oncology treatment paradigms. Head and neck cancer (HNC) patients are generally at high-risk for COVID-19 infection and severe adverse outcomes. Further, there are new, multilevel COVID-19-specific risks to patients, surgeons, health care workers (HCWs), institutions and society. Urgent guidance in the delivery of safe, quality head and neck oncologic care is needed. Novel barriers to safe HNC surgery include: (1) imperfect presurgical screening for COVID-19; (2) prolonged SARS-CoV-2 aerosolization; (3) occurrence of multiple, potentially lengthy, aerosol generating procedures (AGPs) within a single surgery; (4) potential incompatibility of enhanced personal protective equipment (PPE) with routine operative equipment; (5) existential or anticipated PPE shortages. Additionally, novel, COVID-19-specific multilevel risks to HNC patients, HCWs and institutions, and society include: use of immunosuppressive therapy, nosocomial COVID-19 transmission, institutional COVID-19 outbreaks, and, at some locations, societal resource deficiencies requiring health care rationing. Traditional head and neck oncology doctrines require reassessment given the extraordinary COVID-19-specific risks of surgery. Emergent, comprehensive management of these novel, multilevel surgical risks are needed. Until these risks are managed, we temporarily favor nonsurgical therapy over surgery for most mucosal squamous cell carcinomas, wherein surgery and nonsurgical therapy are both first-line options. Where surgery is traditionally preferred, we recommend multidisciplinary evaluation of multilevel surgical-risks, discussion of possible alternative nonsurgical therapies and shared-decision-making with the patient. Where surgery remains indicated, we recommend judicious preoperative planning and development of COVID-19-specific perioperative protocols to maximize the safety and quality of surgical and oncologic care.

MicroRNA-101 (miR-101) post-transcriptionally regulates the expression of EP4 receptor in colon cancers.

PURPOSE: Expression of the PGE2 receptor, EP4, is up-regulated during colorectal carcinogenesis. However the mechanism leading to deregulation of the EP4 receptor is not known. The present study was conducted to investigate the regulation of EP4 receptor by miRNAs. EXPERIMENTAL DESIGN: We analyzed 26 colon cancers (i.e. 15 adenocarcinomas and 9 adenomas) and 16 normal colon specimens for EP4 receptor expression by immunohistochemistry. A bioinformatics approached identified putative microRNA binding sites with the 3'-UTR of the EP4 receptor. Both colon cancer cell lines and tumor specimens were analyzed for miR-101 and EP4 expression by qRT-PCR and Western analysis respectively and simultaneously in situ hybridizations was used to confirm our results. In vitro and in vivo assays were used to confirm our clinical findings. RESULTS: We observed an inverse correlation between the levels of miR-101 and EP4 receptor protein. Transfection of LS174T cells with miR-101 significantly suppressed a luciferase reporter containing the EP4 receptor-3'-UTR. In contrast, a mutant EP4 receptor-3'-UTR construct was unaffected. Ectopic expression of miR-101 markedly reduced cell proliferation and motility. Co-transfection of EP4 receptor could rescue colon cancer cells from the tumor suppressive effects of miR-101. Moreover, the pharmacologic inhibition of EP4 receptor signaling or silencing of EP4 receptor phenocopied the effect of miR-101. This is the first study to show that the EP4 receptor is negatively regulated by miR-101. CONCLUSIONS: These data provide new insights in the modulation of EP-4 receptor expression at the post-transcriptional level by miR-101 and suggests therapeutic strategies against miR-101 targets may be warranted.

Mechanism of PNA transport to the nuclear compartment.

We evaluated the nuclear uptake of fluorescently labeled peptide nucleic acids and measured the binding of unlabeled peptide nucleic acids (PNAs) to the endogenous HER-2/neu promotor in digitonin-permeabilized SK-BR-3 cells. Fluorescently labeled PNAs readily enter the nucleus of digitonin-permeabilized cells, and binding to the chromosomal target sequence was detected with a bis-PNA. Nuclear uptake and target sequence binding were inhibited by N-ethylmaleimide (NEM) and GTPgammaS. We conclude that PNAs are transported into the nucleus through an energy-dependent process involving the nuclear pore complex.

Targeting and regulation of the HER-2/neu oncogene promoter with bis-peptide nucleic acids.

Antigene oligonucleotides have the potential to regulate gene expression through site-specific DNA binding. However, in vivo applications have been hindered by inefficient cellular uptake, degradation, and strand displacement. Peptide nucleic acids (PNAs) address several of these problems, as they are resistant to degradation and bind DNA with high affinity. We designed two cationic pyrimidine bis-PNAs (cpy-PNAs) to target the polypurine tract of the HER-2/neu promoter and compared them to an unmodified phosphodiester triplex-forming oligonucleotide (TFO1) and a TFO-nitrogen mustard conjugate (TFO2). PNA1 contains a + 2 charge and bound two adjacent 9-bp target sequences with high affinity and specificity, but only at low pH. PNA2 contains a +5 charge and bound one 11-bp target with high affinity up to pH 7.4, but with lower specificity. The PNA:DNA:PNA triplex formed by these cpy-bis-PNAs presented a stable barrier to DNA polymerase extension. The cpy-bis-PNAs and the TFO-alkylator conjugate prevented HER-2/neu transcription in a reporter gene assay (TFO2 = PNA1 > PNA2 >> TFO1). Both PNAs and TFOs were effective at binding the target sequence in naked genomic DNA, but only the TFO-alkylator (TFO2) and the more cationic PNA (PNA2) were detected at the endogenous HER-2/neu promoter in permeabilized cells. This work demonstrates the potential for preventing HER-2/neu gene expression with cpy-bis-PNAs in tumor cells.