Human papilloma virus (HPV) infection is a major risk factor for a distinct subset of head and neck squamous cell carcinoma (HNSCC). The current review summarizes the epidemiology of HNSCC and the disease burden, the infectious cycle of HPV, the roles of viral oncoproteins, E6 and E7, and the downstream cellular events that lead to malignant transformation. Current techniques for the clinical diagnosis of HPV‐associated HNSCC will also be discussed, that is, the detection of HPV DNA, RNA, and the HPV surrogate marker, p16 in tumor tissues, as well as HPV‐specific antibodies in serum. Such methods do not allow for the early detection of HPV‐associated HNSCC and most cases are at an advanced stage upon diagnosis. Novel noninvasive approaches using oral fluid, a clinically relevant biological fluid, allow for the detection of HPV and cellular alterations in infected cells, which may aid in the early detection and HPV‐typing of HNSCC tumors. Noninvasive diagnostic methods will enable early detection and intervention, leading to a significant reduction in mortality and morbidity associated with HNSCC.

There are few effective treatments for metastatic melanoma. Checkpoint kinase 1 (Chk1) inhibitors are being trialled for their efficacy in enhancing conventional chemotherapeutic agents, but their effectiveness as single agents is not known. We have examined the effectiveness of two novel Chk1 selective inhibitors, AR323 and AR678, in a panel of melanoma cell lines and normal cell types. We demonstrate that these drugs display single-agent activity, with IC50s in the low nanomolar range. The drugs produce cytotoxic effects in cell lines that are most sensitive to these drugs, whereas normal cells are only sensitive to these drugs at the higher concentrations where they have cytostatic activity. The cytotoxic effect is the consequence of inhibition of S-phase Chk1, which drives cells prematurely from late S phase into an aberrant mitosis and results in either failure of cytokinesis or cell death through an apoptotic mechanism. The sensitivity to the Chk1 inhibitors was correlated with the level of endogenous DNA damage indicating replicative stress. Chk1 inhibitors are viable single-agent therapies that target melanoma cells with high levels of endogenous DNA damage. This sensitivity suggests that Chk1 is a critical component of an adaptation to replicative stress in these cells. It also suggests that markers of DNA damage may be useful in identifying the melanomas and potentially other tumour types that are more likely to be sensitive to Chk1 inhibitors as single agents.

Human papilloma virus-16 (HPV-16) infection is a major risk factor for a subset of head and neck squamous cell carcinoma (HNSCC), in particular oropharyngeal squamous cell carcinoma (OPSCC). Current techniques for assessing the HPV-16 status in HNSCC include the detection of HPV-16 DNA and p16INK4a expression in tumor tissues. When tumors originate from hidden anatomical sites, this method can be challenging. A non-invasive and cost-effective alternative to biopsy is therefore desirable for HPV-16 detection especially within a community setting to screen at-risk individuals. The present study compared detection of HPV-16 DNA and RNA in salivary oral rinses with tumor p16INK4a status, in 82 HNSCC patients using end-point and quantitative polymerase chain reaction (PCR). Of 42 patients with p16INK4a-positive tumours, 39 (sensitivity = 92.9 %, PPV = 100 % and NPV = 93 %) had oral rinse samples with detectable HPV-16 DNA, using end-point and quantitative PCR. No HPV-16 DNA was detected in oral rinse samples from 40 patients with p16INK4a negative tumours, yielding a test specificity of 100 %. For patients with p16INK4a positive tumours, HPV-16 mRNA was detected using end-point reverse transcription PCR (RT-PCR) in 24/40 (sensitivity = 60 %, PPV = 100 % and NPV = 71 %), and using quantitative RT-PCR in 22/40 (sensitivity = 55 %, PPV = 100 % and NPV = 69 %). No HPV-16 mRNA was detected in oral rinse samples from the p16INK4a-negative patients, yielding a specificity of 100 %. We demonstrate that the detection of HPV-16 DNA in salivary oral rinse is indicative of HPV status in HNSCC patients and can potentially be used as a diagnostic tool in addition to the current methods.

Identification of appropriate reference genes (RGs) is critical to accurate data interpretation in quantitative real-time PCR (qPCR) experiments. In this study, we have utilised next generation RNA sequencing (RNA-seq) to analyse the transcriptome of a panel of non-melanoma skin cancer lesions, identifying genes that are consistently expressed across all samples. Genes encoding ribosomal proteins were amongst the most stable in this dataset. Validation of this RNA-seq data was examined using qPCR to confirm the suitability of a set of highly stable genes for use as qPCR RGs. These genes will provide a valuable resource for the normalisation of qPCR data for the analysis of non-melanoma skin cancer.