The EGFR antibody cetuximab is used to treat numerous cancers, but intrinsic and acquired resistance to this agent is a common clinical problem. In this study we show that overexpression of the oncogenic receptor kinase AXL is sufficient to mediate acquired resistance to cetuximab in models of non-small cell lung cancer (NSCLC) and head and neck squamous cell carcinoma (HNSCC), where AXL was overexpressed, activated and tightly associated with EGFR expression in cells resistant to cetuximab (CtxR cells). Using RNAi methods and novel AXL targeting agents, we found that AXL activation stimulated cell proliferation, EGFR activation and MAPK signaling in CtxR cells. Notably, EGFR directly regulated the expression of AXL mRNA through MAPK signaling and the transcription factor c-Jun in CtxR cells, creating a positive feedback loop that maintained EGFR activation by AXL. Cetuximab-sensitive parental cells were rendered resistant to cetuximab by stable overexpression of AXL or stimulation with EGFR ligands, the latter of which increased AXL activity and association with the EGFR. In tumor xenograft assays, the development of resistance following prolonged treatment with cetuximab was associated with AXL hyperactivation and EGFR association. Furthermore, in an examination of patient-derived xenografts established from surgically resected HNSCCs, AXL was overexpressed and activated in tumors that displayed intrinsic resistance to cetuximab. Collectively, our results identify AXL as a key mediator of cetuximab resistance, providing a rationale for clinical evaluation of AXL targeting drugs to treat cetuximab-resistant cancers.

Purpose The global incidence of oropharyngeal squamous cell carcinoma (OPSCC) has been increasing, and it has been proposed that a rising rate of human papillomavirus (HPV) associated cancers is driving the observed changes in OPSCC incidence. We carried out this systematic review to further examine the prevalence of HPV in OPSCC over time worldwide. Methods A systematic literature search was performed to identify all articles through January 31, 2014 that reported on the prevalence of HPV in OPSCC. Articles that met inclusion criteria were divided into four time frames (pre-1995, 1995—1999, 2000—2004, and 2005—present) based on the median year of the study's sample collection period. Employing a weighted analysis of variance (ANOVA) model, we examined the trends of HPV-positivity over time worldwide, in North America, and in Europe. Results Our literature search identified 699 unique articles. 175 underwent review of the entire study and 105 met inclusion criteria. These 105 articles reported on the HPV prevalence in 9541 OPSCC specimens across 23 nations. We demonstrated significant increases in the percentage change of HPV-positive OPSCCs from pre-1995 to present: 20.6% worldwide (p-value for trend: p<0.001), 21.6% in North America (p=0.013) and 21.5% in Europe (p=0.033). Discussion Interestingly, while in Europe there was a steady increase in HPV prevalence across all time frames, reaching nearly 50% most recently, in North America HPV prevalence appears to have plateaued over the past decade at about 65%. These findings may have important implications regarding predictions for the future incidence of OPSCC.

Purpose Head and neck squamous cell carcinoma (HNSCC) represents the eighth most common malignancy worldwide. Standard of care treatments for HNSCC patients include surgery, radiation and chemotherapy. Additionally, the anti-epidermal growth factor receptor (EGFR) monoclonal antibody cetuximab is often used in combination with these treatment modalities. Despite clinical success with these therapeutics, HNSCC remains a difficult to treat malignancy. Thus, identification of new molecular targets is critical. Experimental Design In the current study, the receptor tyrosine kinase AXL was investigated as a molecular target in HNSCC using established cell lines, HNSCC patient derived xenografts (PDXs), and human tumors. HNSCC dependency on AXL was evaluated with both anti-AXL siRNAs and the small molecule AXL inhibitor R428. Furthermore, AXL inhibition was evaluated with standard of care treatment regimes used in HNSCC. Results AXL was found to be highly overexpressed in several models of HNSCC, where AXL was significantly associated with higher pathologic grade, presence of distant metastases and shorter relapse free survival in patients with HNSCC. Further investigations indicated that HNSCC cells were reliant on AXL for cellular proliferation, migration, and invasion. Additionally, targeting AXL increased HNSCC cell line sensitivity to chemotherapy, cetuximab, and radiation. Moreover, radiation resistant HNSCC cell line xenografts and PDXs expressed elevated levels of both total and activated AXL, indicating a role for AXL in radiation resistance. Conclusion Collectively, this study provides evidence for the role of AXL in HNSCC pathogenesis and supports further pre-clinical and clinical evaluation of anti-AXL therapeutics for the treatment of patients with HNSCC.

The Muller F element (4.2 Mb, ~80 protein-coding genes) is an unusual autosome of Drosophila melanogaster; it is mostly heterochromatic with a low recombination rate. To investigate how these properties impact the evolution of repeats and genes, we manually improved the sequence and annotated the genes on the D. erecta, D. mojavensis, and D. grimshawi F elements and euchromatic domains from the Muller D element. We find that F elements have greater transposon density (25–50%) than euchromatic reference regions (3–11%). Among the F elements, D. grimshawi has the lowest transposon density (particularly DINE-1: 2% vs. 11–27%). F element genes have larger coding spans, more coding exons, larger introns, and lower codon bias. Comparison of the Effective Number of Codons with the Codon Adaptation Index shows that, in contrast to the other species, codon bias in D. grimshawi F element genes can be attributed primarily to selection instead of mutational biases, suggesting that density and types of transposons affect the degree of local heterochromatin formation. F element genes have lower estimated DNA melting temperatures than D element genes, potentially facilitating transcription through heterochromatin. Most F element genes (~90%) have remained on that element, but the F element has smaller syntenic blocks than genome averages (3.4–3.6 vs. 8.4–8.8 genes per block), indicating greater rates of inversion despite lower rates of recombination. Overall, the F element has maintained characteristics that are distinct from other autosomes in the Drosophila lineage, illuminating the constraints imposed by a heterochromatic milieu.

Human papillomaviruses (HPVs) are involved in approximately 5% of all human cancer. Although initially recognized for causing nearly all cases of cervical carcinoma, much data has now emerged implicating HPVs as a causal factor in other anogenital cancers as well as a subset of head and neck squamous cell carcinomas (HNSCCs), most commonly oropharyngeal cancers. Numerous clinical trials have demonstrated that patients with HPV+ oropharyngeal squamous cell carcinoma (OPSCC) have improved survival compared to patients with HPV– cancers. Furthermore, epidemiological evidence shows the incidence of OPSCC has been steadily rising over time in the United States. It has been proposed that an increase in HPV-related OPSCCs is the driving force behind the increasing rate of OPSCC. Although some studies have revealed an increase in HPV+ head and neck malignancies over time in specific regions of the United States, there has not been a comprehensive study validating this trend across the entire country. Therefore, we undertook this meta-analysis to assess all literature through August 2013 that reported on the prevalence of HPV in OPSCC for patient populations within the United States. The results show an increase in the prevalence of HPV+ OPSCC from 20.9% in the pre-1990 time period to 51.4% in 1990–1999 and finally to 65.4% for 2000–present. In this manner, our study provides further evidence to support the hypothesis that HPV-associated OPSCCs are driving the increasing incidence of OPSCC over time in the United States.

Objective Patients with COVID-19 are at risk for laryngeal injury and dysfunction secondary to respiratory failure, prolonged intubation, and other unique facets of this illness. Our goal is to report clinical features and treatment for patients presenting with voice, airway, and/or swallowing concerns postacute COVID-19. Study Design Case series. Setting Academic tertiary care center. Methods Patients presenting with laryngeal issues following recovery from COVID-19 were included after evaluation by our laryngology team. Data were collected via retrospective chart review from March 1, 2020, to April 1, 2021. This included details of the patient’s COVID-19 course, initial presentation to laryngology, and subsequent treatment. Results Twenty-four patients met inclusion criteria. Twenty (83%) patients were hospitalized, and 18 required endotracheal intubation for a median (range) duration of 14 days (6-31). Ten patients underwent tracheostomy. Patients were evaluated at a median 107 days (32-215) after their positive SARS-CoV-2 test result. The most common presenting concerns were dysphonia (n = 19, 79%), dyspnea (n = 17, 71%), and dysphagia (n = 6, 25%). Vocal fold motion impairment (50%), early glottic injury (39%), subglottic/tracheal stenosis (22%), and posterior glottic stenosis (17%) were identified in patients who required endotracheal intubation. Patients who did not need intubation were most frequently treated for muscle tension dysphonia (67%). Conclusion Patients may develop significant voice, airway, and/or swallowing issues postacute COVID-19. These complications are not limited to patients requiring intubation or tracheostomy. Multidisciplinary laryngology clinics will continue to play an integral role in diagnosing and treating patients with COVID-19–related laryngeal sequelae.

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Background Patient derived xenografts (PDXs) represent an essential tool in oncologic research, and we sought to further expand our repertoire of head and neck squamous cell carcinoma (HNSCC) while determining potential boundaries for this system. Methods We consented new patients for PDX development and determined if a 24-hour time delay from tumor excision to xenograft implantation affected PDX establishment. We developed a tissue microarray (TMA) from formalin fixed, paraffin embedded PDXs and their subsequent passages and carried out quantitative immunohistochemistry for EGFR, pEGFR, pAkt, pERK and ERCC1. First and last passaged PDXs were compared via a paired t-test to examine for the stability of protein expression across passages. We performed a similar comparison of the mutational profile of the patient tumor and resulting xenografts using a targeted sequencing approach. Results No patient/tumor characteristics influenced PDX take rate and the 24-hour time delay from tumor excision to xenograft implantation did not affect PDX establishment, growth or histology. There was no significant difference in biomarker expression between the first and last passaged PDXs for EGFR, pEGFR, pAkt, and ERCC1. For pERK there was a significant difference (p=0.002), but further analysis demonstrated this only arose in three of 15 PDXs. Targeted sequencing revealed striking stability of passenger and likely driver mutations from patient to xenograft. Conclusions The stability of protein expression across PDX passages will hopefully allow greater investigation of predictive biomarkers in order to identify ones for further pre-clinical and clinical investigation.