Defining the criteria for radioresistant laryngeal cancer

P53 and pRB induction improves response to radiation therapy in HPV-positive laryngeal squamous cell carcinoma

INTRODUCTION

Patients with Human Papillomavirus (HPV+)-associated Laryngeal Squamous Cell Carcinoma (LSCC) exhibit dramatically improved survival relative to those with HPV-Negative (HPV-) tumors. In this study, the authors aimed to investigate the radiosensitivity of all available confirmed HPV+ and HPV-LSCC cells in vitro and in vivo.

METHODS

Primary LSCC cells were generated from tumor specimens obtained from patients. Real-time PCR was performed to confirm HPV infection and the expression of HPV-related genes (E6 and E7), p53, and pRB. Clonogenic survival assays, western blotting, and flow cytometry were used to assess radiation sensitivity, apoptosis, and the expression of p53 and pRB. p53 and pRB knockout cells were generated using CRISPR/Cas9 technology.

RESULTS

HPV+ LSCC cells displayed enhanced radiation sensitivity compared to HPV- cells. Radiation-induced apoptosis in HPV+ LSCC cells, accompanied by increased levels of p53 and pRB. Knockout of p53 or pRB led to radiation resistance and attenuated radiation-induced apoptosis in HPV+ LSCC cells. In vivo experiments showed similar results, where knockout of p53 or pRB decreased radiosensitivity in tumor-bearing mice.

CONCLUSION

The present findings demonstrated that HPV+ LSCC cells displayed obvious inherent radiation sensitivity, corresponding to increased apoptosis following radiation exposure. Mechanism study showed that the expression of p53 and pRB in HPV+ cells are required for radiation sensitivity. These findings highlight a novel mechanism by which p53 and pRB play key roles in the radiation sensitivity of HPV+ LSCC compared to HPV-LSCC.

Early glottic cancer recurrence: A critical review on its current management

INTRODUCTION

Recurrent early glottic cancer (rEGC) poses several issues in terms of timely diagnosis, correct re-staging, and treatment. We want to critically review the latest evidence about rEGC considering its epidemiology, biology, diagnostic challenges, and treatment strategies.

METHODS

A systematic search of the literature using PubMed from 1990 to October 31, 2020 was performed.

RESULTS

There are many different treatment options available (open surgery, transoral mini-invasive surgery, radiotherapy), and many factors related to the patient's status and previous treatments must be considered when planning the best management strategy for rEGC. While its overall prognosis remains satisfactory, it is of the utmost importance to appreciate all the clinical implications derived from the choice of the initial therapeutic modality, and from a correct primary and recurrent staging.

CONCLUSION

The balance between oncological and voice and swallowing functions represents the fundamental principle underlying rEGC management. Future studies should focus on molecular profiling of rEGC, and on the results of the emerging radiation delivery techniques and mini-invasive procedures.

Genetic imbalances detected by multiplex ligation-dependent probe amplification in a cohort of patients with oral squamous cell carcinoma-the first step towards clinical personalized medicine

Oral tumors are a growing health problem worldwide; thus, it is mandatory to establish genetic markers in order to improve diagnosis and early detection of tumors, control relapses and, ultimately, delineate individualized therapies. This study was the first to evaluate and discuss the clinical applicability of a multiplex ligation-dependent probe amplification (MLPA) probe panel directed to head and neck cancer. Thirty primary oral squamous cell tumors were analyzed using the P428 MLPA probe panel. We detected genetic imbalances in 26 patients and observed a consistent pattern of distribution of genetic alterations in terms of losses and gains for some chromosomes, particularly for chromosomes 3, 8, and 11. Regarding the latter, some specific genes were highlighted due to frequent losses of genetic material--RARB, FHIT, CSMD1, GATA4, and MTUS1--and others due to gains--MCCC1, MYC, WISP1, PTK2, CCND1, FGF4, FADD, and CTTN. We also verified that the gains of MYC and WISP1 genes seem to suggest higher propensity of tumors localized in the floor of the mouth. This study proved the value of this MLPA probe panel for a first-tier analysis of oral tumors. The probemix was developed to include target regions that have been already shown to be of diagnostic/prognostic relevance for oral tumors. Furthermore, this study emphasized several of those specific genetic targets, suggesting its importance to oral tumor development, to predict patients' outcomes, and also to guide the development of novel molecular therapies.

Prognostic significance of HIF-1a, CA-IX, and OPN in T1-T2 laryngeal carcinoma treated with radiotherapy

OBJECTIVES/HYPOTHESIS

To examine the prognostic value of hypoxia inducible factor HIF-1a, CA-IX, and OPN on clinical outcome in patients with T1-T2 supraglottic laryngeal squamous cell carcinoma (LSCC) treated with primarily radiotherapy (RT).

STUDY DESIGN

Retrospective cohort study.

METHODS

Tumor tissue sections of 60 patients with T1-T2 supraglottic LSCC treated with primarily radiotherapy were assessed immunohistochemically for expression of HIF-1a, CA-IX, and OPN. The relationship of protein expression and classical clinical parameters with clinical outcome was studied, using Cox regression and Kaplan-Meier survival analyses.

RESULTS

Neither HIF-1a nor CA-IX was of prognostic significance toward local control or overall survival in T1-T2 supraglottic LSCC. Cox regression survival analysis showed no relation between HIF-1a or CA-IX expression and local control (HR [hazard ratio] 1.07, CI [95% confidence interval] 0.29-3.87; HR 0.34, CI 0.04-2.58). Furthermore, OPN expression was not associated with local control (HR 1.37, CI 0.45-4.17) and overall survival (HR 0.99, CI 0.44-2.21). Our earlier findings in T1-T2 glottic LSCC (Schrijvers et al., 2008) could not be confirmed.

CONCLUSION

The absence of prognostic significance for HIF-1a and CA-IX toward local control in supraglottic LSCC, unlike glottic LSCC, suggests that supraglottic LSCC might represent another biological entity.

Differential proteomics in the search for biomarkers of radiotherapy resistance

The individualization of radiotherapy treatment would be beneficial for cancer patients; however, there are no predictive biomarkers of radiotherapy resistance in routine clinical use. This article describes the body of work in this field where comparative proteomics methods have been used for the discovery of putative biomarkers associated with radiotherapy resistance. A large number of differentially expressed proteins have been reported, mostly from the study of novel radiotherapy-resistant cell lines. Here, we have assessed these putative biomarkers through the discovery, confirmation and validation phases of the biomarker pipeline, and inform the reader on the current status of proteomics-based findings. Suggested avenues for future work are discussed.

Amplicon mapping and expression profiling identify the Fas-associated death domain gene as a new driver in the 11q13.3 amplicon in laryngeal/pharyngeal cancer

PURPOSE

Amplification of the 11q13 region is a frequent event in human cancer. The highest incidence (36%) is found in head and neck squamous cell carcinomas. Recently, we reported that the amplicon size in 30 laryngeal and pharyngeal carcinomas with 11q13 amplification is determined by unique genomic structures, resulting in the amplification of a set of genes rather than a single gene.

EXPERIMENTAL DESIGN

To investigate which gene(s) drive the 11q13 amplicon, we determined the smallest region of overlap with amplification and the expression levels of all genes within this amplicon.

RESULTS

Using array-based comparative genomic hybridization analysis, we detected a region of approximately 1.7 Mb containing 13 amplified genes in more than 25 of the 29 carcinomas. Quantitative reverse transcription-PCR revealed that overexpression of 8 potential driver genes including, cyclin D1, cortactin, and Fas-associated death domain (FADD), correlated significantly with DNA amplification. FADD protein levels correlated well with DNA amplification, implicating that FADD is also a candidate driver gene in the 11q13 amplicon. Analysis of 167 laryngeal carcinomas showed that increased expression of FADD (P = 0.007) and Ser(194) phosphorylated FADD (P = 0.011) were associated with a worse disease-specific survival. FADD was recently reported to be involved in cell cycle regulation, and cancer cells expressing high levels of the Ser(194) phosphorylated isoform of FADD proved to be more sensitive to Taxol-induced cell cycle arrest.

CONCLUSION

Because of the frequent amplification of the 11q13 region and concomitant overexpression of FADD in head and neck squamous cell carcinomas, we hypothesize that FADD is a marker to select patients that might benefit from Taxol-based chemoradiotherapy.