Genomic profiling identifies common HPV-associated chromosomal alterations in squamous cell carcinomas of cervix and head and neck

<p>Abstract</p> <p>Background</p> <p>It is well known that a persistent infection with high-risk human papillomavirus (hrHPV) is causally involved in the development of squamous cell carcinomas of the uterine cervix (CxSCCs) and a subset of SCCs of the head and neck (HNSCCs). The latter differ from hrHPV-negative HNSCCs at the clinical and molecular level.</p> <p>Methods</p> <p>To determine whether hrHPV-associated SCCs arising from different organs have specific chromosomal alterations in common, we compared genome-wide chromosomal profiles of 10 CxSCCs (all hrHPV-positive) with 12 hrHPV-positive HNSCCs and 30 hrHPV-negative HNSCCs. Potential organ-specific alterations and alterations shared by SCCs in general were investigated as well.</p> <p>Results</p> <p>Unsupervised hierarchical clustering resulted in one mainly hrHPV-positive and one mainly hrHPV-negative cluster. Interestingly, loss at 13q and gain at 20q were frequent in HPV-positive carcinomas of both origins, but uncommon in hrHPV-negative HNSCCs, indicating that these alterations are associated with hrHPV-mediated carcinogenesis. Within the group of hrHPV-positive carcinomas, HNSCCs more frequently showed gains of multiple regions at 8q whereas CxSCCs more often showed loss at 17p. Finally, gains at 3q24-29 and losses at 11q22.3-25 were frequent (>50%) in all sample groups.</p> <p>Conclusion</p> <p>In this study hrHPV-specific, organ-specific, and pan-SCC chromosomal alterations were identified. The existence of hrHPV-specific alterations in SCCs of different anatomical origin, suggests that these alterations are crucial for hrHPV-mediated carcinogenesis.</p

Preclinical in Vivo Activity of 2',2'-Difluorodeoxycytidine (Gemcitabine) against Human Head and Neck Cancer

2',2'-Difluorodeoxycytidine (dFdCyd, Gemcitabine) is a new deoxycytidine analogue with striking preclinical antitumor activity in solid tumors from murine and human origin. In this study, dFdCyd was tested for its antitumor effect in human tumor xenografts derived from squamous cell carcinoma of the head and neck (SCCHN). NMRI nude mice bearing s.c. growing tumors with a volume of 50 to 150 mm3 were given i.p. injections of a maximum tolerated dose of 120 mg/kg dFdCyd, every 3 days for four injections. A significant antitumor effect was observed in all five tested SCCHN tumor lines; in four of these lines the median tumor volume doubling time increased more than a 3-fold upon dFdCyd treatment. In two lines dFdCyd was curative (no tumor regrowth 90 days after treatment) in one of six and two of eight xenografts, respectively. Schedule dependency was investigated in three SCCHN lines, showing, in the two most sensitive lines, that treatment with a 3-day interval was superior to the schedules with daily or weekly injections. At equitoxic doses, dFdCyd was more active in this model than the drugs that are clinically used in SCCHN, i.e., cisplatin, methotrexate, 5-fluorouracil, and cyclophosphamide. dFdCyd is a good candidate for clinical trials with SCCHN patients

Involvement of cell cycle control in bleomycin-induced mutagen sensitivity

Bleamycin-induced chromosomal instability, generally referred to as mutagen sensitivity, is associated with an increased risk for the development of environmentally related cancer including head and neck squamous cell carcinoma and lung cancer. On average, the cultured lymphocytes of patients with these types of cancer show an increased number of chromatid breaks per cell after bleomycin exposure in the late S or G2 phase of the cell cycle as compared to lymphocytes from control persons. The aim of the present study was to investigate whether cell cycle regulation is involved in mutagen sensitivity. We determined cell cycle arrest after bleomycin-induced DNA damage in 21 lymphoblastoid cell lines that varied in mutagen sensitivity score. An ataxia telangiectasia (AT) cell line was included for comparison. Using a cut-off point of 0.70 breaks per cell, eight cell lines were classified as insensitive and 13 cell lines showed the hypersensitive phenotype. Compared to insensitive cell lines, bleamycin-treated hypersensitive cells remained at a relatively high level of DNA synthesis, as measured by thymidine incorporation, and showed a decreased accumulation of cells in G2 and M phase, as measured by flow cytometry. AT cells showed an extremely high mutagen sensitivity score, a high level of DNA synthesis, and a strong G2 block. In conclusion, mutagen sensitivity is associated with "damage-resistant growth," which is indicative of impaired cell cycle arrest. By which specific pathway(s) this checkpoint defect is explained has yet to be elucidated; however, it is probably distinct from the checkpoint defect in AT cells

Preclinical chemotherapy on human head and neck cancer xenografts grown in athymic nude mice

This study was undertaken to investigate the potential role of xenografts established from human head and neck squamous cell carcinoma (HNSCC) in the selection of new anticancer agents for phase M clinical trials. Eight HNSCC tumor lines were established in NMRI nude mice. The tumor‐bearing animals were then treated with drugs at the maximum tolerated dose level. Treatment with drugs known for their activity in 15%–30% of HNSCC patients [cisplatin (CDDP), bleomycin (BLEO), 5‐fluorouracil (5‐Fu), cyclophosphamide (CY), and doxorubicin (DOX)] caused strong responses in up to 38% and moderate responses in 50%–67% of the HNSCC tumor lines. Methotrexate (MTX), known to cause remissions in about 40% of HNSCC patients, was only minimally active in this model system. A clinically ineffective drug, amsacrine (m‐AMSA), was included as a negative control and showed no or minimal activity in all four HNSCC lines tested. A number of experimental drugs that have promising preclinical activity were also tested. Brequinar sodium (Dup 785) and 10‐ethyl, 10‐deaza‐aminopterin (10‐EdAM) showed activity in three of five, and two of the four tested tumor lines respectively. N, N‐dimethylformamide (DMF) and 5‐aza‐2′‐deoxycytidine (5‐aza‐dCyd), agents with the capacity to induce differentiation in in vitro systems, showed moderate activity in 43% and 40%, and strong activity in 14% and 40% of the lines, respectively. Our results indicate that the nude mouse xenograft model may play a role in the screening of new drugs, and in particular, it could be of help in the selection of drugs to be tested in phase II HNSCC clinical trials

Human lymphoblastoid proteome analysis reveals a role for the inhibitor of acetyltransferases complex in DNA double-strand break response

A DNA double-strand break (DSB) is highly cytotoxic; it emerges as the type of DNA damage that most severely affects the genomic integrity of the cell. It is essential that DNA DSBs are recognized and repaired efficiently, in particular, prior to mitosis, to prevent genomic instability and eventually, the development of cancer. To assess the pathways that are induced on DNA DSBs, 14 human lymphoblastoid cell lines were challenged with bleomycin for 30 and 240 minutes to establish the fast and more prolonged response, respectively. The proteomes of 14 lymphoblastoid cell lines were investigated to account for the variation among individuals. The primary DNA DSB response was expected to occur within the nucleus; therefore, the nuclear extracts were considered. Differential analysis was done using two-dimensional difference in gel electrophoresis; paired ANOVA statistics were used to recognize significant changes in time. Many proteins whose nuclear levels changed statistically significantly showed a fast response, i.e., within 30 minutes after bleomycin challenge. A significant number of these proteins could be assigned to known DNA DSB response processes, such as sensing DSBs (Ku70), DNA repair through effectors (high-mobility group protein 1), or cell cycle arrest at the G 2-M phase checkpoint (14-3-3 ζ). Interestingly, the nuclear levels of all three proteins in the INHAT complex were reduced after 30 minutes of bleomycin challenge, suggesting that this complex may have a role in changing the chromatin structure, allowing the DNA repair enzymes to gain access to the DNA lesions

Electronic Cigarettes and Head and Neck Cancer Risk-Current State of Art

Simple Summary The risk of developing cancer is always higher for tobacco smokers than for non-smokers. Electronic cigarettes (e-cigarettes) have become increasingly popular in the last decade and are considered less harmful than traditional tobacco products, due to the lower content of toxic and carcinogenic compounds. However, this is still a controversial issue. This paper contains a review of previous reports on the composition of e-cigarettes and their impact on the pathogenesis and risk of head and neck cancer (HNC). The authors reviewed articles on both toxic and carcinogenic compounds contained in e-cigarettes and their molecular and health effects on the upper respiratory tract in comparison to traditional tobacco cigarettes. In conclusion, the studies discussed in the review strongly suggest that more long-term studies are needed to better address the safety of e-cigarettes. E-cigarettes have become increasingly popular in the last decade and are considered less harmful than traditional tobacco products due to the lower content of toxic and carcinogenic compounds. However, this is still a controversial issue. This paper contains a review of previous reports on the composition of e-cigarettes and their impact on the pathogenesis and risk of head and neck cancer (HNC). The objective of the review was to compare the molecular and health effects of e-cigarette use in relation to the effects of traditional cigarette smoking in the upper respiratory tract, and to assess the safety and effect of e-cigarettes on HNC risk. A review for English language articles published until 31 August 2020 was made, using a PubMed (including MEDLINE), CINAHL Plus, Embase, Cochrane Library and Web of Science data. The authors reviewed articles on both toxic and carcinogenic compounds contained in e-cigarettes and their molecular and health effects on the upper respiratory tract in comparison to tobacco cigarettes. The risk of developing head and neck squamous cell carcinoma (HNSCC) remains lower in users of e-cigarettes compared with tobacco smokers. However, more long-term studies are needed to better address the safety of e-cigarettes.Peer reviewe

Genetic Classification of Oral and Oropharyngeal Carcinomas Identifies Subgroups with a Different Prognosis

The common risk factors for oral and oropharyngeal cancer are tobacco smoking and alcohol consumption, and recently the human papillomavirus (HPV) was shown to be involved in a subgroup. HPV-positive and -negative carcinomas can be distinguished on basis of their genetic profiles. Aim of this study was to investigate patterns of chromosomal aberrations of HPV-negative oral and oropharyngeal squamous cell carcinomas (OOSCC) in order to improve stratification of patients regarding outcome. Thirty-nine OOSCCs were classified on basis of their genetic pattern determined by array comparative genomic hybridization (aCGH). Resulting groups were related to patient and tumor characteristics using the Fisher’s exact test and in addition to survival with the Kaplan–Meier and log rank tests. Classification distinguished three groups, one characterized by hardly any chromosomal aberration (N = 8) and another by a relatively high level (N = 26), and one with a very high level (N = 5) of chromosomal aberrations. This classification was significantly (p = 0.003) associated with survival, with the best survival in the genetically ‘silent’ group and the worst survival in the most aberrant group. The silent profile was significantly (p < 0.05) associated with wild-type TP53, an absence of alcohol consumption and a female gender. These carcinomas were negative for microsatellite instability. This classification of OOSCC was confirmed in an independent set of 89 oral carcinomas. In conclusion, the discovery of these new classes of oral and oropharyngeal cancer with unique genetic and clinical characteristics has important consequences for future basic and clinical studies