Raptor and rictor expression in patients with human papillomavirus-related oropharyngeal squamous cell carcinoma.

BACKGROUND: Despite reports of a link between human papillomavirus (HPV) infection and mechanistic target of rapamycin (mTOR) signaling activation, the role of the mTOR pathway, especially raptor and rictor, in HPV-related head and neck cancer is still unclear. The aim of the present study was to elucidate the role of the mTOR pathway in HPV-related oropharyngeal squamous cell carcinoma (OPSCC). METHODS: The present study involved two strategies. The first was to investigate the activity of mTOR and mTOR-related complexes in high-risk HPV-positive (UM-SCC47 and CaSki) and HPV-negative (SCC-4 and SAS) cancer cell lines. The second was to elucidate mTOR complex expression in 80 oropharyngeal cancer tissues and to examine the relationship between mTOR complex expression and survival in patients with OPSCC. RESULTS: The UM-SCC47 and CaSki cell lines showed high gene and protein expression of raptor. They also exhibited G1/S and G2/M phase cell cycle arrest following 24 h incubation with 6 µM temsirolimus, a rapamycin analog, and temsirolimus administration inhibited their growth. HPV-related OPSCC samples showed high gene and protein expression of raptor and rictor compared with HPV-unrelated OPSCC. In addition, HPV-related OPSCC patients with high raptor and rictor expression tended to have a worse prognosis than those with low or medium expression. CONCLUSIONS: These results suggest that raptor and rictor have important roles in HPV-related OPSCC and that temsirolimus is a potential therapeutic agent for patients with HPV-related OPSCC. This is the first report to reveal the overexpression of raptor and rictor in HPV-related OPSCC.

ERCC1 C8092A polymorphism predicts fair survival outcome in Japanese patients with pharyngo-laryngeal squamous cell carcinoma.

PURPOSE: To evaluate the prognostic significance of DNA excision repair gene polymorphisms, excision repair cross-complementation group 1 (ERCC1) and X-ray repair complementing defective repair in Chinese hamster cells 1 (XRCC1) polymorphisms were investigated in Japanese patients with head and neck squamous cell carcinoma (HNSCC). METHODS: A total of 225 consecutive patients with HNSCC who underwent surgery or chemoradiotherapy/radiotherapy (CRT/RT) with curative intent as primary treatment from 2006 to 2017 were recruited. ERCC1 C8092A and XRCC1 Arg399Gln polymorphisms in DNA extracted from individual blood samples were determined by the polymerase chain reaction-restriction fragment length polymorphism method. Cumulative survival was estimated by Kaplan-Meier analysis with a log-rank test and Cox proportional hazards model stratified by treatment arm, adjusting for clinical prognostic factors. RESULTS: Multivariate analysis showed that carriers with the ERCC1 8092 (C/A+A/A) genotype (hazard ratio, 3.56; 95% confidence interval, 1.22-7.39; p = 0.02) had significantly worse survival than those with ERCC1 8092 C/C who received CRT/RT. Conversely, the XRCC1 Arg399Gln polymorphism did not influence survival in patients who received CRT/RT as well as surgery. CONCLUSION: The ERCC1 C8092A polymorphism might be an independent predictor of response to CRT and survival outcome in patients with HNSCC. This is the first report to investigate the role of DNA excision repair gene polymorphisms in patients with head and neck cancer in a Japanese population.

Staging and prognosis of oropharyngeal carcinoma according to the 8th Edition of the American Joint Committee on Cancer Staging Manual in human papillomavirus infection.

PURPOSE: The aim of this study was to evaluate the 8th edition of the American Joint Committee on Cancer Staging Manual: Head and Neck Section on oropharyngeal squamous cell cancer (OPSCC) and to clarify the relationship between p16 overexpression and the presence of human papillomavirus (HPV) DNA using fresh frozen samples. METHODS: Samples from 100 OPSCC patients were analyzed using polymerase chain reaction (PCR) and p16 immunohistochemistry. RESULTS: Five-year overall survival (OS) was 73.0%, 93.9%, and 62.2% in all, p16-positive (n = 34), and p16-negative (n = 66) cases, respectively. OS tended to be better aligned with stage in the 8th edition than in the 7th edition. The 5-year OS was 96.0% in never or light smokers (< 40 pack-years), and 87.5% in heavy smokers (≥ 40 pack-years) in the p16-positive group, respectively (p = 0.027). HPV infection was found in 100% of p16-positive and 21.2% of p16-negative cases. The p16-positive cases had higher viral load and integrated physical status than the p16-negative cases. Although 1 case with p16 overexpression showed no PCR amplification using consensus primers, PCR amplification was detected using HPV 16 E6-specific primers. CONCLUSIONS: The 8th edition predicts OPSCC prognosis more accurately than the 7th edition and p16-overexpression is an excellent surrogate marker for detecting HPV infection. Although high-risk-type HPV infection was observed in p16-negative cases, it showed no significant effect in survival outcome.

Induction Chemotherapy in Hypopharyngeal Cancer: Influence of DNA Repair Gene Polymorphisms.

BACKGROUND/AIM: The aim was to clarify whether DNA repair gene polymorphisms can be used to predict response to cisplatin, 5-fluorouracil, and docetaxel (TPF) as induction chemotherapy (ICT) in Japanese patients with hypopharyngeal cancer (HPC). MATERIALS AND METHODS: DNA repair gene polymorphisms (rs3212986, rs1799793, rs13181, and rs25487) were analyzed in 117 HPC patients and 125 control subjects by PCR-restriction fragment length polymorphism. Forty-one HPC patients who received TPF-based ICT, followed by surgery or chemoradiotherapy/radiotherapy were analyzed for ICT response, laryngeal preservation, and survival outcome. RESULTS: ICT responders (29 cases) had significantly better overall survival than ICT non-responders (12 cases; 86.0% vs. 37.0%, respectively, p<0.01 by log-rank test) and better laryngeal preservation rates. The DNA repair gene polymorphisms were not related to ICT response. CONCLUSION: ICT is beneficial for chemoselection of HPC patients, but a role for DNA repair gene polymorphisms in ICT response was not confirmed.

High-risk type human papillomavirus infection and p16 expression in laryngeal cancer.

BACKGROUND: Oropharyngeal cancers associated with high-risk type human papillomavirus (HR-HPV) infection have better prognosis than virus negative cancers. Similarly, the HPV status in laryngeal cancer (LC) may be associated with better outcome. METHODS: Samples from 88 patients with LC were investigated using the polymerase chain reaction (PCR) and p16 immunohistochemistry for HR-HPV analysis. The cut-off point for p16 overexpression was diffuse (≥75%) tumor expression with at least moderate (+ 2/3) staining intensity. RESULTS: The 5-year cumulative survival (CS) rate was 80.7% in all patients with LC. According to a combination of HR-HPV DNA status and p16 overexpression, subjects with LC were divided into four groups: HR-HPV DNA-positive/p16 overexpression-positive (n = 5, 5.7%; CS = 100%), HR-HPV DNA-positive/p16 overexpression-negative (n = 11, 12.5%; CS =81.8%), HR-HPV DNA-negative/p16 overexpression-positive (n = 0), and HR-HPV DNA-negative/p16 overexpression-negative (n = 72, 81.8%; CS = 79.5%). HR-HPV DNA-positive/p16-positive cases tended to have integrated HPV infection and high viral load, compared with HR-HPV DNA-positive/p16 overexpression-negative cases. CONCLUSIONS: LC patients with HPV infection and high levels of p16 expression might have an improved survival outcome; however, it is necessary to recruit additional LC cases with HPV infection to determine the definitive characteristics of HPV-mediated LC and estimate survival outcome. These results may contribute to the development of a useful method for selecting patients with a potentially fair response to treatment and ensure laryngeal preservation.