Background: Secretory carcinoma (SC) is a rare form of salivary carcinoma that was first described in 2010 and is characterized by ETV6::NTRK3 fusion in most cases. In this large retrospective study, we aimed to identify adverse clinicopathologic factors and propose a prognostically relevant grading scheme for SC. Methods: A detailed clinicopathologic review was conducted on 90 SCs from the major and minor salivary glands. Results: The median age at presentation was 50 years (range: 7-93). Sixty-nine (77%) tumors originated from major salivary glands, whereas the remaining 21 involved minor salivary glands. Six cases (7%) had cervical nodal metastasis. Only lymphovascular invasion (LVI) was associated with risk of nodal metastasis (p<0.05). The 5-year disease specific survival and disease-free survival (DFS) were 98% and 87% respectively. On univariate survival analysis, adverse prognostic factors associated with decreased DFS included minor salivary gland origin, atypical mitosis, high mitotic index, high-grade transformation (HGT), necrosis, nuclear pleomorphism, infiltrative tumor border, fibrosis at the invasive front, LVI, positive margin, and advanced pT stage (p<0.05). When adjusted for pT stage and margin status: mitotic index, LVI, nuclear pleomorphism, and HGT remained as independent prognostic factors. Conclusion: We therefore propose a two-tiered grading system for SC. The low-grade SC is defined as those with <5 mitoses/10 high power fields and no tumor necrosis, and high-grade SC as those with ≥5 mitoses/10 high power fields and/or necrosis. This proposed grading system can be useful to risk stratify patients with SC for appropriate clinical management.

Although recent studies demonstrate active mitochondrial metabolism in cancers, the precise mechanisms through which mitochondrial factors contribute to cancer metastasis remain elusive. Through a customized mitochondrion RNAi screen, we identified succinyl-CoA ligase ADP-forming subunit beta (SUCLA2) as a critical anoikis resistance and metastasis driver in human cancers. Mechanistically, SUCLA2, but not the alpha subunit of its enzyme complex, relocates from mitochondria to the cytosol upon cell detachment where SUCLA2 then binds to and promotes the formation of stress granules. SUCLA2-mediated stress granules facilitate the protein translation of antioxidant enzymes including catalase, which mitigates oxidative stress and renders cancer cells resistant to anoikis. We provide clinical evidence that SUCLA2 expression correlates with catalase levels as well as metastatic potential in lung and breast cancer patients. These findings not only implicate SUCLA2 as an anticancer target, but also provide insight into a unique, noncanonical function of SUCLA2 that cancer cells co-opt to metastasize.

Metastasis is the leading cause of death in patients with breast, lung, and head and neck cancers. However, the molecular mechanisms underlying metastases in these cancers remain unclear. We found that the p90 ribosomal S6 kinase 2 (RSK2)- cAMP response element-binding protein (CREB) pathway is commonly activated in diverse metastatic human cancer cells, leading to up-regulation of a CREB transcription target Fascin- 1. We also observed that the protein expression patterns of RSK2 and Fascin-1 correlate in primary human tumor tissue samples from head and neck squamous cell carcinoma patients. Moreover, knockdown of RSK2 disrupts filopodia formation and bundling in highly invasive cancer cells, leading to attenuated cancer cell invasion in vitro and tumor metastasis in vivo, whereas expression of Fascin-1 significantly rescues these phenotypes. Furthermore, targeting RSK2 with the small molecule RSK inhibitor FMK-MEA effectively attenuated the invasive and metastatic potential of cancer cells in vitro and in vivo, respectively. Taken together, our findings for the first time link RSK2-CREB signaling to filopodia formation and bundling through the up-regulation of Fascin-1, providing a proinvasive and prometastatic advantage to human cancers. Therefore, protein effectors of the RSK2-CREB-Fascin-1 pathway represent promising biomarkers and therapeutic targets in the clinical prognosis and treatment of metastatic human cancers.

Human papilloma virus (HPV) causes a subset of head and neck squamous cell carcinomas (HNSCC) of the oropharynx. We combined targeted DNA- and genome-wide RNA-sequencing to identify genetic variants and gene expression signatures respectively from patients with HNSCC including oropharyngeal squamous cell carcinomas (OPSCC). DNA and RNA were purified from 35- formalin fixed and paraffin embedded (FFPE) HNSCC tumor samples. Immuno-histochemical evaluation of tumors was performed to determine the expression levels of p16INK4A and classified tumor samples either p16+ or p16-. Using ClearSeq Comprehensive Cancer panel, we examined the distribution of somatic mutations. Somatic single-nucleotide variants (SNV) were called using GATK-Mutect2 (“tumor-only” mode) approach. Using RNA-seq, we identified a catalog of 1,044 and 8 genes as significantly expressed between p16+ and p16-, respectively at FDR 0.05 (5%) and 0.1 (10%). The clinicopathological characteristics of the patients including anatomical site, smoking and survival were analyzed when comparing p16+ and p16- tumors. The majority of tumors (65%) were p16+. Population sequence variant databases, including gnomAD, ExAC, COSMIC and dbSNP, were used to identify the mutational landscape of somatic sequence variants within sequenced genes. Hierarchical clustering of The Cancer Genome Atlas (TCGA) samples based on HPV-status was observed using differentially expressed genes. Using RNA-seq in parallel with targeted DNA-seq, we identified mutational and gene expression signatures characteristic of p16+ and p16- HNSCC. Our gene signatures are consistent with previously published data including TCGA and support the need to further explore the biologic relevance of these alterations in HNSCC.

Background The benefit of combined chemoradiation in elderly patients with human papillomavirus (HPV)-positive locally advanced oropharyngeal squamous cell carcinoma (SCC) must be balanced with the potential for higher toxicity rates. We performed a retrospective review of our institutional experience. Methods Patients 70 years or older with p16-positive oropharyngeal SCC treated with definitive chemoradiation from 2005 to 2013 were evaluated. Overall survival (OS), disease-free survival (DFS), and locoregional failure-free survival were calculated. Results Twenty-one eligible patients had a follow-up of 22.4 months. Estimated 5-year OS, DFS, and locoregional failure-free survival were 76.0%, 40%, and 95%, respectively. There was 1 death from acute toxicity, and 50% had unplanned hospitalizations. Sixty percent had late toxicity, and 6-month feeding tube dependence was 25%. Conclusion Elderly patients with HPV-positive locally advanced SCC of the oropharynx treated with definitive chemoradiation had good OS but high rates of acute and long-term toxicity.

Microtubule-associated serine/threonine kinase 1 (MAST1) is a central driver of cisplatin resistance in human cancers. However, the molecular mechanism regulating MAST1 levels in cisplatin-resistant tumors is unknown. Through a proteomics screen, we identified the heat shock protein 90 B (hsp90B) chaperone as a direct MAST1 binding partner essential for its stabilization. Targeting hsp90B sensitized cancer cells to cisplatin predominantly through MAST1 destabilization. Mechanistically, interaction of hsp90B with MAST1 blocked ubiquitination of MAST1 at lysines 317 and 545 by the E3 ubiquitin ligase CHIP and prevented proteasomal degradation. The hsp90B-MAST1-CHIP signaling axis and its relationship with cisplatin response were clinically validated in cancer patients. Furthermore, combined treatment with a hsp90 inhibitor and the MAST1 inhibitor lestaurtinib further abrogated MAST1 activity and consequently enhanced cisplatin-induced tumor growth arrest in a patient-derived xenograft model. Our study not only uncovers the regulatory mechanism of MAST1 in tumors but also suggests a promising combinatorial therapy to overcome cisplatin resistance in human cancers.

Purpose: This study was designed to seek associations between positron emission tomography/computed tomography (PET/CT) parameters, contrast enhanced neck computed tomography (CECT) and pathological findings, and to determine the potential prognostic value of PET/CT and CECT parameters in oral cavity squamous cell carcinoma (OCSCC). Materials and method: 36 OCSCC patients underwent staging PET/CT and 30/36 of patients had CECT. PET/CT parameters were measured for the primary tumor and the hottest involved node, including maximum, mean, and peak standardized uptake values (SUV max, SUV mean, and SUV peak), metabolic tumor volume (MTV), total lesion glycolysis (TLG), standardized added metabolic activity (SAM), and normalized standardized added metabolic activity (N SAM). Qualitative assessment of PET/CT and CECT were also performed. Pathological outcomes included: perineural invasion, lymphovascular invasion, nodal extracapsular spread, grade, pathologic T and N stages. Multivariable logistic regression models were fit for each parameter and outcome adjusting for potentially confounding variables. Multivariable Cox proportional hazards models were used for progression free survival (PFS), locoregional recurrence free survival (LRFS), overall survival (OS) and distant metastasis free survival (DMFS). Results: In multivariable analysis, patients with high (≥ median) tumor SUV max (OR 6.3), SUV mean (OR 6.3), MTV (OR 19.0), TLG (OR 19.0), SAM (OR 11.7) and N SAM (OR 19.0) had high pathological T-stage (T3/T4) (p < 0.05). Ring/heterogeneous pattern on CECT qualitative assessment was associated with worse DMFS and OS. Conclusion: High PET/CT parameters were associated with pathologically advanced T stage (T3/T4). Qualitative assessment of CECT has prognostic value. PET/CT parameters did not predict clinical outcome.

Purpose: Previous studies revealed diverging results regarding the role of survivin in squamous cell carcinoma of the head and neck (SCCHN). This study aimed to evaluate the clinical significance of survivin expression in SCCHN; the function of survivin in DNA-damage repair following ionizing radiation therapy (RT) in SCCHN cells; and the potential of honokiol to enhance RT through downregulation of survivin. Experimental Design: Expression of survivin in SCCHN patient primary tumor tissues (n ¼ 100) was analyzed and correlated with clinical parameters. SCCHN cell lines were used to evaluate the function of survivin and the effects of honokiol on survivin expression in vitro and in vivo. Results: Overexpression of survivin was significantly associated with lymph nodes' metastatic status (P ¼ 0.025), worse overall survival (OS), and disease-free survival (DFS) in patients receiving RT (n ¼ 65, OS: P ¼ 0.024, DFS: P ¼ 0.006) and in all patients with SCCHN (n ¼ 100, OS: P ¼ 0.002, DFS: P ¼ 0.003). In SCCHN cells, depletion of survivin led to increased DNA damage and cell death following RT, whereas overexpression of survivin increased clonogenic survival. RT induced nuclear accumulation of survivin and its molecular interaction with g-H2AX and DNA-PKCs. Survivin specifically bound to DNA DSB sites induced by I-SceI endonuclease. Honokiol (which downregulates survivin expression) in combination with RT significantly augmented cytotoxicity in SCCHN cells with acquired radioresistance and inhibited growth in SCCHN xenograft tumors. Conclusions: Survivin is a negative prognostic factor and is involved in DNA-damage repair induced by RT. Targeting survivin using honokiol in combination with RT May provide novel therapeutic opportunities.

How altered metabolism contributes to chemotherapy resistance in cancer cells remains unclear. Through a metabolism-related kinome RNAi screen, we identified inositol-trisphosphate 3-kinase B (ITPKB) as a critical enzyme that contributes to cisplatin-resistant tumor growth. We demonstrated that inositol 1,3,4,5-tetrakisphosphate (IP4), the product of ITPKB, plays a critical role in redox homeostasis upon cisplatin exposure by reducing cisplatin-induced ROS through inhibition of a ROS-generating enzyme, NADPH oxidase 4 (NOX4), which promotes cisplatin-resistant tumor growth. Mechanistically, we identified that IP4 competes with the NOX4 cofactor NADPH for binding and consequently inhibits NOX4. Targeting ITPKB with shRNA or its small-molecule inhibitor resulted in attenuation of NOX4 activity, imbalanced redox status, and sensitized cancer cells to cisplatin treatment in patient-derived xenografts. Our findings provide insight into the crosstalk between kinase-mediated metabolic regulation and platinum-based chemotherapy resistance in human cancers. Our study also suggests a distinctive signaling function of IP4 that regulates NOX4. Furthermore, pharmaceutical inhibition of ITPKB displayed synergistic attenuation of tumor growth with cisplatin, suggesting ITPKB as a promising synthetic lethal target for cancer therapeutic intervention to overcome cisplatin resistance.

Background Pathologic extranodal extension (ENE) has traditionally guided the management of head and neck cancers. The prognostic value of radiographic ENE (rENE) in HPV-associated oropharyngeal squamous cell carcinoma (HPV+OPX) is uncertain. Methods HPV+OPX patient with adequate pre-treatment radiographic nodal evaluation, from a single institution were analyzed. rENE status was determined by neuroradiologists’ at time of diagnosis. Distant metastasis-free survival (DMFS), overall survival (OS), locoregional recurrence-free survival (LRFS) and were estimated using Kaplan-Meier methods. Cox proportional hazards models were fit to assess the impact of rENE on survival endpoints. Results 168 patients with OPX+SCC diagnosed between April 2008 and December 2014 were included for analysis with median follow-up of 3.3 years. Eighty-eight percent of patients received concurrent chemoradiotherapy. rENE was not prognostic; its presence in HPV+OPX patients did not significantly impact OS, LRFS, or DMFS. Conclusions In patients with HPV+OPX, rENE was not significantly associated with OS, LRFS, or DMFS.