Expression of apoptosis-related genes in human head and neck squamous cell carcinomas undergoing p53-mediated programmed cell death.

Human head and neck squamous cell carcinoma (HNSCC) lines infected with a replication-defective Ad5CMV-p53 vector bearing a wild-type human p53 gene were used to examine alterations in the production of proteins implicated in regulating apoptosis. Because HNSCC lines express abundant levels of c-myc, and simultaneous expression of c-myc and p53 is known to trigger apoptosis in other cells, cooperation between these two genes was examined. Surprisingly, levels of c-myc mRNA and protein were rapidly and profoundly suppressed after infection with wild-type p53. Suppression of c-myc using antisense oligodeoxynucleotides (in the absence of p53) was sufficient to trigger apoptosis in Tu-138 cells, raising the possibility that the reduction of c-myc may be involved in at least one of the cell death pathways mediated by p53. Expression of a panel of Bcl-2 homology proteins was also examined in HNSCC lines undergoing p53-mediated apoptosis. No changes in Bcl-2, Bak, or Bcl-xS were found after p53 expression. Increased levels of the apoptosis-accelerating protein Bax were found in HNSCC lines after infection with Ad5CMV-p53. Induction of the apoptosis-inhibiting protein Bcl-xL was observed in Tu-167 cells and may account for the delayed onset of apoptosis in these cells. These studies suggest that multiple pathways may regulate apoptosis after transient overexpression of p53.     

Current trends in head and neck squamous cell carcinomas

Squamous cell carcinomas of the head and neck remain frequent in France with an evolving epidemiology. Progress was observed both in diagnostic and treatments. Increasing possibilities of curative treatment should be provided within next years through surgery, radiotherapy, chemotherapy and target therapies as well as high performance imaging modalities and molecular biology and tumoral markers. Surgical techniques have improved function preservation while non surgical means have increased efficacy through chemo-radiotherapy. Assessment of optimal sequential therapeutic strategies is required, including both oncologic efficacy and quality of life.     

MAPKs activation in head and neck squamous cell carcinomas

Cancer of head and neck (HN) represents a diffused group of neoplasia; despite advances in clinical treatment its mortality rate has remained high, mainly because it is frequently diagnosed only at an advanced stage. Molecular markers allowing the diagnosis at an early stage would be useful. Mitogen-activated protein kinases (MAPK) are a family of protein kinases, which transduces extracellular stimuli into intracellular responses, controlling proliferation, differentiation and apoptosis. Given their key role in the regulation of cell survival and proliferation, MAPKs have been deeply studied in cancer. Furthermore, they are of particular interest in HN cancer progression, since they are downstream of one of the most frequently found alterations in this cancer: the over-expression of the epidermal growth factor receptor. Although a deregulation of MAPK expression and activation has been reported in several type of cancers, data regarding their role in HN cancer progression are contrasting, thus the aim of this short review is to summarize the data from literature regarding MAPKs activation in this type of cancer.     

人类乳头状瘤病毒感染与头颈部鳞状细胞癌

大量基础和临床研究的证据显示,人类乳头状瘤病毒(HPV)感染和头颈部鳞状细胞癌(HNSCC)的发生发展有关,但两者间确切发病机制尚不明确.HPV表达E6和E7导致被感染细胞发生恶性转化是其主要的致癌机制.HPV阳性HNSCC对放化疗更为敏感,预后更好.HPV疫苗可能成为预防和治疗HNSCC的重要手段.     

Expression profiles of angiogenic growth factors in squamous cell carcinomas of the head and neck

Inhibition of angiogenesis by blocking angiogenic cytokines or their pathways has become a major target in experimental cancer therapies. This therapeutical approach requires a profound knowledge of growth factor profiles that contribute to tumor growth and progression. The respective knowledge is presently rather incomplete for head and neck squamous cell carcinomas (HNSCC). Therefore we studied expression of several angiogenic cytokines including VEGF, bFGF, PDGF-AB, PDGF-BB, G-CSF and GM-CSF in HNSCC in vivo and in vitro. In tumor tissues expression of all cytokines was observed albeit with marked differences concerning intensity and distribution pattern. Quantification of the cytokines in the supernatant of 15 tissue-corresponding HNSCC cultures revealed that VEGF, PDGF-AB and less frequently GM-CSF were secreted in high amounts of up to 13 ng/ml/10(6) cells. Twenty percent of the HNSCC cultures expressed only 1 cytokine in biologically active amounts, 60% 2 or 3 and 20% expressed the maximum of 4 cytokines simultaneously. Interestingly, we observed a distinct cytokine pattern: HNSCC cells secreting only 1 or 2 cytokines presented always with either VEGF and/or PDGF-AB, while G-CSF and GM-CSF were secreted primarily together with VEGF and PDGF-AB. The number of cytokines expressed by HNSCC cells correlated with the microvessel density of the original tumor and with the clinical outcome: tumors producing at least 3 cytokines revealed a significantly poorer patient prognosis. Our data indicate a major role for VEGF and PDGF-AB in HNSCC and that the additional secretion of G-CSF or GM-CSF might contribute to a poorer prognosis in patients suffering from these tumors.     

Overexpression of Pim-1 in head and neck squamous cell carcinomas

Despite ongoing developments of treatment protocols head and neck squamous cell carcinomas (HNSCC) show only marginal improvement in outcome, which has been attributed to a lack of therapy individualized to tumor biological properties. We compared mRNA expression profiles of HNSCC and normal epithelial cells using differential display to identify gene fragments showing differential expression in HNSCC cells. We identified a 127-bp long fragment to be overexpressed in HNSCC cells that revealed a 98.4% homology with the Pim-1 mRNA. The differential expression was confirmed by Northern hybridization. Immunohistochemistry showed overexpression of the Pim-1 protein in 98% (41/42) of invasive HNSCC. Analysis of Pim-1 protein expression in relation to TNM stage and histological grade of the tumors exhibited no significant correlation. However, when samples of primary tumor and metastasis retrieved from the same patients (n=26) were analyzed, nearly significant correlation of Pim-1 expression with histological grade was found (p=0.06). The high frequency of the Pim-1 expression of HNSCC of different grades and stages in conjunction with its absence in non-neoplastic head and neck squamous cell epithelium underlines the functional role of Pim-1 in molecular processes of HNSCC.     

Targeting EGF-receptor-signalling in squamous cell carcinomas of the head and neck

Despite significant advances in the use of surgery, chemotherapy and radiotherapy to treat squamous cell carcinoma of the head and neck (SCCHN), prognosis has improved little over the past 30 years. There is a clear need for novel, more effective therapies to prevent relapse, control metastases and improve overall survival. Improved understanding of SCCHN disease biology has led to the introduction of molecularly targeted treatment strategies in these cancers. The epidermal growth factor receptor (EGFR) is expressed at much higher levels in SCCHN tumours than in normal epithelial tissue, and EGFR expression correlates with poor prognosis. Therefore, much effort is currently directed toward targeting aberrant EGFR activity (e.g. cell signalling) in SCCHN. This review discusses the efficacy of novel therapies targeting the EGFR (e.g. anti-EGFR antibodies and EGFR tyrosine kinase inhibitors) that are currently tested in SCCHN patients.     

Clinical trial design limitations in head and neck squamous cell carcinomas

PURPOSE OF REVIEW: The present article reviews the randomized trials contributing to the establishment of current standards for the treatment of head and neck cancer. It provides critical analysis of their methodology in order to facilitate future trial design. RECENT FINDINGS: From a prognosis perspective, head and neck cancers are a heterogeneous group of diseases. Following a number of randomized clinical trials evaluating the role of chemotherapy in the induction, concomitant and adjuvant settings, there has been considerable improvement in the treatment of locally advanced head and neck cancers during the last decade. It is, however, difficult to interpret and compare the results optimally and to build on efficient trial designs as most of the trials included patients with different levels of essential prognostic factors. SUMMARY: All key randomized trials will be reviewed according to eligibility criteria, subgroup issues, trial power and historical controls. Methodological interpretation and possible plans for the next generation of clinical trials will be presented.     

Time-dose-response relationships in postoperatively irradiated patients with head and neck squamous cell carcinomas.

BACKGROUND AND PURPOSE: To define the influence of the dose and time on the response to treatment in postoperatively irradiated head and neck cancer patients and to establish a good prediction of failure. METHODS AND MATERIALS: From January 1985 to December 1995, 214 patients with histologically proven head and neck squamous cell carcinomas were irradiated after radical surgery or single tumour resection according to surgical and histopathological findings. The total doses given ranged between 50 and 75 Gy to the primary bed tumour and between 42 and 56 Gy to the neck with fraction sizes of 1.7-2 Gy/day. The median length of the time interval between surgery and radiotherapy, time of irradiation and total treatment time were 81, 59 and 139 days, respectively. The end-point analyzed was the local-regional tumour control rate at the primary tumour bed and neck for 5 years from the beginning of radiotherapy. Univariate and multivariate analyses were used to determine predictors of failure from among the following studied variables: (i), clinical stage (T/N) of the patients; (ii), tumour grade; (iii), neck surgery; (iv), tumour margins; (v), histological tumour nodal extension; (vi), chemotherapy; (vii), normalized total dose; (viii), time interval between surgery and radiotherapy; (ix), time of irradiation; and (x), total treatment time. RESULTS: The actuarial 5-year tumour control rate for the entire group was 72%, and 92% of the patients who achieved local control are currently alive without disease. Tumour control was inversely related to T stage (83% for T2 vs. 57% for T4) and the probability of local control within each stage was dependent on the N status (> or =71% for T3-T4/N0 vs. 31-44% for T3-T4/N1-N3). Histological N status and tumour margins, but not tumour grade, impacted significantly on tumour control. When local control was analyzed as a function of the dose to the primary, a non-significant negative dose-response relationship was found. The total treatment time was a significant prognostic factor, and the time interval between surgery and irradiation proved to be an independent predictor of failure. CONCLUSIONS: Despite the absence of a statistically significant dose-response relationship, the present results suggest that postoperative irradiation treatment given to patients with head and neck squamous cell carcinomas should not be unduly prolonged, in order to minimize the amount of tumour cell proliferation. In these patients, nodal involvement, positive margins of the resected specimens and time interval between surgery and irradiation were the most important prognostic factors.     

Pathology of squamous carcinomas of the head and neck.

Recent publications have been critically reviewed to illustrate some of the newer approaches that may eventually provide more precise prognostic information from tumor biopsies. Examples include changes in expression of various surface antigens, DNA ploidy, and alterations at the level of molecular genetics, eg, gene amplification. Other molecular changes in tumor tissue, such as point mutations and loss of normal tumor suppressor genes, are also giving clues to underlying carcinogenic mechanisms.     

Synchronous and metachronous squamous cell carcinomas of the head and neck mucosal sites.

PURPOSE: The present study presents the experience at the University of Florida with synchronous and metachronous squamous cell carcinomas of the head and neck mucosal sites. PATIENTS AND METHODS: This study included 1,112 patients with squamous cell carcinomas of the oropharynx, hypopharynx, and supraglottic larynx treated with radiation therapy with curative intent from 1964 to 1997. All patients had follow-up for at least 2 years. No patients were lost to follow-up. RESULTS: The overall survival rate was 45% and the disease-specific survival rate was 67% at 5 years after initial diagnosis of carcinoma of the head and neck mucosal sites. Seventy-seven patients (7%) presented with synchronous carcinomas of the head and neck mucosal sites and 103 patients (9%) developed metachronous carcinomas of the head and neck mucosal sites at 0.6 to 21.7 years (median, 3.6 years). The overall survival rate was 31%, and the disease-specific survival rate was 50% at 5 years after metachronous carcinomas of the head and neck mucosal sites. Seven patients (1%) developed metachronous carcinomas of the thoracic esophagus at 1 to 11.1 years (median, 2.8 years), 15 patients (1%) presented with synchronous carcinomas of the lung, and 83 patients (7%) developed metachronous carcinomas of the lung at 0.6 to 17.6 years (median, 3.5 years). CONCLUSION: Development of synchronous and metachronous squamous cell carcinomas of the head and neck mucosal sites are in part responsible for failure to improve overall survival rates for patients with squamous cell carcinomas of the head and neck mucosal sites, justifying rigorous follow-up and studies on chemoprevention.     

Chromosome instability and risk of squamous cell carcinomas of head and neck

In 895 subjects with squamous cell carcinoma of the head and neck (SCCHN) and 898 cancer-free controls matched by age, sex, and ethnicity, we validated our previous finding that mutagen sensitivity as measured by the frequency of chromatid breaks in vitro induced by benzo[a]pyrene diol epoxide (BPDE) is an independent risk factor for SCCHN. Using a previously established concentration of 4 micromol/L BPDE to treat short-term cultured primary lymphocytes for 5 hours, we evaluated chromatid breaks in 50 well-spread metaphases for each blood sample. The mean frequency of BPDE-induced chromatid breaks was significantly higher in cases than in controls in non-Hispanic Whites (P = 0.0003) but not in other ethnic groups (P = 0.549 for Hispanic Americans and 0.257 for African Americans). The odds ratio associated with risk of SCCHN for the frequency of chromatid breaks greater than median value of controls was 1.56 (95% confidence interval, 1.27-1.91) in non-Hispanic Whites (767 cases and 763 controls) after adjustment for age, sex, smoking status, and drinking status. When the quartiles of the controls were used as the cutoff values, there was a dose response between the degree of mutagen sensitivity and risk of SCCHN in non-Hispanic Whites (P(trend) = 0.0001). However, none of these associations in non-Hispanic Whites was identified in Hispanic Americans (69 cases and 70 controls) or African Americans (59 cases and 65 controls), possibly because of the small samples of these ethnic groups or ethnic difference in genetic variation, which needs to be confirmed in future studies.     

Cytogenetic evidence of the multistep origin of head and neck squamous cell carcinomas.

BACKGROUND: Head and neck squamous cell carcinomas are associated with tobacco and alcohol use; therefore, the incidence of this type of tumor is expected to rise in the future as a result of the increasing numbers of female and adolescent smokers. Previous reports of cytogenetic analysis of this type of tumor have implicated a number of chromosomal regions in recurring changes, but no clear pattern of characteristic changes has emerged. PURPOSE: We have undertaken cytogenetic analysis of 10 cell lines which were established from squamous cell carcinomas of the head and neck, to determine the possible sites of additional tumor suppressor genes and oncogenes that may contribute to malignant transformation. METHODS: Metaphases were harvested from cultures of cells in the exponential growth phase, following exposure to Colcemid (demecolcine) at a final concentration of 30 ng/mL for 5 hours. Air-dried slides were G-banded using trypsin and Giemsa. Fifteen metaphases were photographed and fully karyotyped. RESULTS: We observed that several chromosomal regions were lost at high frequency, including 18q (10 of 10 lines), 10p (eight of 10 lines), 3p (six of 10 lines), 8p (seven of 10 lines), and the short arms of the acrocentric chromosomes (seven of 10 lines). Nine of 10 lines had additional copies of 7p. We also noted clustering of breakpoints in a number of chromosome bands, including 1p22, 10q11.2, 11q13, and the short arms of the acrocentric chromosomes. CONCLUSION: The observation of loss of multiple chromosomal regions in a significant number of lines analyzed is consistent with the theory that tumorigenesis occurs as the result of the accumulation of a number of genetic alterations, as proposed for colorectal carcinoma. The high frequency with which these changes are seen suggests that genes located in these regions have a role in the etiology of this type of tumor.     

DNA--cytometric studies on xenografts of squamous cell carcinomas of the head and neck.

The primary tumors of four human head and neck carcinomas and their xenografts in nude mice were analysed with respect to their histological features and DNA-ploidy level using DNA-flow and DNA-image cytometry. The histological characteristics of the xenografts and the DNA-index did not differ from those of the parent tumors, whereas the growth rate remained unchanged during serial passaging. DNA-flow cytometric analysis revealed the presence of both aneuploid and euploid cells in both parent tumors and their xenografts. During passaging the proportion of aneuploid cells increased. Analysis of the different cell populations by DNA-image cytometry revealed the presence of aneuploid tumor cells and euploid host cells. This study demonstrates that the characteristics of the original tumors in terms of histological features and DNA-ploidy are retained after xenografting.     

Management and outcome of head and neck squamous cell carcinomas in obese patients

Head and neck squamous cell carcinomas are common lesions, related to chronic smoking and drinking behaviors. But in contrast to other cancers, effect of obesity on occurrence, diagnosis, treatment and prognosis of these tumors remains to date unknown. This is a retrospective review of 111 obese patients (sex ratio=6.4, median age=54.5 year old), treated between 1999 and 2007. Risk factors, tumoral localization and staging (41% stage I-II) were the same as in general population. However, we found 26.1% difficult pan-endoscopies, 54% ACE-27 comorbidity scores ≥2 and 22.5% misstaged cervical lymphadenopathy. Treatment was based upon surgery (61%) or radiotherapy-chemotherapy (39%), and 37% of patients developed complications. Median follow up (38 months) and five-year overall survival (50%) are comparable to data in non obese patients. Although no direct relation between obesity and squamous cell carcinomas of the head and neck was found, obesity causes problems in tumor assessment and increases surgical complications rate. However, final good therapeutic tolerance and overall survival rate show that these patients should be managed like normal weighted ones. Receiving optimal treatments allow them to anticipate equivalent outcome as in general population.     

Expression of the E-cadherin-catenin cell adhesion complex in primary squamous cell carcinomas of the head and neck and their nodal metastases.

Reductions in cell-cell adhesion and stromal and vascular invasion are essential steps in the progression from localized malignancy to metastatic disease. In this study, changes in the expression of the components of the E-cadherin-catenin cell adhesion complex have been investigated using immunohistochemical techniques in primary tumours and nodal metastases from 36 patients with squamous cell carcinoma of the head and neck. For 14 patients the corresponding primary and nodal metastases samples were available. None of the 51 samples showed normal E-cadherin expression when compared with either the adjacent normal squamous epithelium or with normal colonic epithelium that was used as positive control material. In 88% of primary tumours fewer than 50% of cells exhibited normal membranous E-cadherin expression. Loss of membranous E-cadherin expression was more extensive in poorly differentiated carcinomas while, in individual carcinomas, membranous E-cadherin expression was stronger in those parts of the neoplasm that expressed the differentiation marker involucrin. Expression of beta-catenin generally paralleled that of E-cadherin, but in 12 cases there was strong membranous beta-catenin expression in samples that exhibited predominantly cytoplasmic E-cadherin labelling. Expression of alpha-catenin was generally weak and did not correlate with the expression of either beta-catenin or E-cadherin. Marked intratumoral heterogeneity for protein expression was evident for all antibodies, and the abnormal expression of the catenins is a novel finding. E-cadherin is expressed more intensely in cells with greater squamous differentiation, but there was no correlation between the decreased expression of any of the adhesion molecules of the E-cadherin complex tested and local recurrence, metastasis or survival. The loss of expression of components of the E-cadherin complex is a common abnormality in squamous carcinomas and, while it may be permissive for metastasis, it does not appear to be the only determinant of this process.     

Complex karyotypes in flow cytometrically DNA-diploid squamous cell carcinomas of the head and neck.

In squamous cell carcinoma of the head and neck (SCCHN), DNA ploidy as determined by flow cytometry (FCM) has been found to yield prognostic information but only for tumours at oral sites. Cytogenetic findings have indicated complex karyotype to be a correlate of poor clinical outcome. In the present study, 73 SCCHN were investigated with the two techniques. Aneuploid cell populations were identified in 49 (67%) cases by FCM but in only 21 (29%) cases by cytogenetic analysis. The chromosome index (CI), calculated as the mean chromosome number divided by 46, was compared with the respective DNA index (DI) obtained by FCM in 15 tumours, non-diploid according to both techniques, DI being systematically 12% higher than CI in this subgroup. Eight (33%) of the 24 tumours diploid according to FCM had complex karyotypes, three of the tumours being cytogenetically hypodiploid, three diploid and two non-diploid. The findings in the present study may partly explain the low prognostic value of ploidy status as assessed by FCM that has been observed in SCCHN. In addition, we conclude that FCM yields information of the genetic changes that is too unspecific, and that cytogenetic analysis shows a high rate of unsuccessful investigations, thus diminishing the value of the two methods as prognostic factors in SCCHN.