Survivin blockade sensitizes rhabdomyosarcoma cells for lysis by fetal acetylcholine receptor-redirected T cells.

Cellular immunotherapy may provide a strategy to overcome the poor prognosis of metastatic and recurrent rhabdomyosarcoma (RMS) under the current regimen of polychemotherapy. Because little is known about resistance mechanisms of RMS to cytotoxic T cells, we investigated RMS cell lines and biopsy specimens for expression and function of immune costimulatory receptors and anti-apoptotic molecules by RT-PCR, Western blot analysis, IHC, and cytotoxicity assays using siRNA or transfection-modified RMS cell lines, together with engineered RMS-directed cytotoxic T cells specific for the fetal acetylcholine receptor. We found that costimulatory CD80 and CD86 were consistently absent from all RMSs tested, whereas inducible T-cell co-stimulator ligand (ICOS-L; alias B7H2) was expressed by a subset of RMSs and was inducible by tumor necrosis factor α in two of five RMS cell lines. Anti-apoptotic survivin, along with other inhibitor of apoptosis (IAP) family members (cIAP1, cIAP2, and X-linked inhibitor of apoptosis protein), was overexpressed by RMS cell lines and biopsy specimens. Down-regulation of survivin by siRNA or pharmacologically in RMS cells increased their susceptibility toward a T-cell attack, whereas induction of ICOS-L did not. Treatment of RMS-bearing Rag(-/-) mice with fetal acetylcholine receptor-specific chimeric T cells delayed xenograft growth; however, this happened without definitive tumor eradication. Combined blockade of survivin and application of chimeric T cells in vivo suppressed tumor proliferation during survivin inhibition. In conclusion, survivin blockade provides a strategy to sensitize RMS cells for T-cell-based therapy.

Tonsillar swabs and sputum predict SLPI- and AnxA2 expression in tonsils: A prospective study on smoking dependent SLPI- and AnxA2-expression, and tonsillar HPV infection.

Previous retrospective studies have elucidated a correlation between secretory leucocyte protease inhibitor (SLPI) and Annexin A2 (AnxA2), patient smoking status and tonsillar human papilloma virus (HPV) status. The current study assessed these parameters prospectively and to the best of our knowledge, analyzed SLPI-/AnxA2-expression for the first time in tonsillar swabs and sputum. Samples were obtained from 52 patients with tonsillar squamous cell carcinoma and 163 patients with tonsillar hyperplasia (H; n=56) and chronic or recurrent tonsillitis (CRT; n=107). HPV-DNA, SLPI and AnxA2 gene expression was analyzed in sputum, tonsillar swabs and tissue by performing reverse transcription-quantitative PCR. Results were compared with smoking status, revealing that smoking resulted in significantly increased SLPI gene expression in all biomaterials of all cases. SLPI-gene expression was significantly decreased in all HPV-DNA-positive samples (tissue/swab/sputum), while AnxA2 was significantly increased in all HPV-DNA-positive samples. Results from swabs and sputum were able to predict SLPI- and AnxA2 gene expression of the corresponding tonsil. The current prospective study confirmed previous retrospective results underlining this hypothesis: Smoking enhances SLPI-expression, preventing HPV-binding to AnxA2. HPV-binding to AnxA2 appears essential for successful cell-entry. SLPI/AnxA2-gene expression in swabs and sputum reflect their expression in tonsillar tissue. Accordingly, a positive AnxA2/SLPI-ratio in sputum/swabs could possibly be used to reduce HPV-associated carcinogenesis, by performing tonsillectomy or HPV-vaccination in patients with positive AnxA2/SLPI-ratios.

HPV DNA/RNA detection in various oral and oropharyngeal biomaterials identifies active HPV infections also in non-neoplastic tonsils.

Previous studies describe a correlation between HPV-positivity and non-smoking in TSCC; p16INK4A-expression as surrogate-marker for HPV-DNA/RNA-positivity is discussed controversially. In the present study, these parameters are assessed prospectively. HPV-status of sputum and tonsillar-swabs was analyzed to determine their validity as surrogate-marker for tissue-HPV-status. TSCC- (n = 52) and non-neoplastic tonsillar tissue (n = 163) were analyzed. HPV-DNA- and HPV-RNA-status of total sputum, cellular fraction and supernatants, tonsillar-swabs and -tissue was determined by (RT)-PCR. Immunohistochemistry determined p16INK4A-expression. 23/163 (14.2%) non-neoplastic tonsils were HPV-DNA-positive; five patients (3 HPV16, 2 HPV11) had active HPV-infections (HPV-RNA-positive), in all biomaterials. 140/163 (85.9%) patients were either HPV-DNA-positive or HPV-DNA-negative in all samples. 21/52 (40.4%) TSCC-tonsils were HPV-DNA-positive; 17 patients were HPV-RNA-positive (14 HPV16; 4 HPV18). 40/52 (76.9%) TSCC-patients were congruent in all biomaterials. p16INK4A-expression alone would have misclassified the HPV-status of 14/52 (26.2%) TSCC-patients. This prospective study confirms the discrepancy between HPV-status and p16INK4A-expression and the significant correlation between non-smoking and HPV-DNA-positivity. HPV-sputum- and/or swab-results do not consistently match tissue-results, possibly having (detrimental) consequences if those were used to assess tissue-HPV-status. In the 5 patients with active HPV infection in the non-neoplasitic tonsils, tonsillectomy likely prevented subsequent development of TSCC.

No association between HPV-status in tonsillar tissue and sexual behavior of the patients in a northern German population - Critical view of the link between HPV natural history and HPV-driven carcinogenesis.

HPV-infection in patients with HNSCC is reportedly correlated with sexual behavior, age, and tobacco/alcohol-consumption. HPV-infections of the oral cavity are regarded as sexually transmitted. Comparable data of patient populations outside the U.S. are sparse or missing. Questionnaires regarding sexual behavior, education tobacco- and alcohol-consumption, were given to 28 patients with tonsillar hyperplasia (H) and 128 patients with tonsillar carcinomas (CA), all with tissue-typed HPV-DNA-status performing PCR. Answers were correlated among groups and HPV-status. 106 questionnaires were analyzed. Comparisons between H- (n = 25) and CA- (n = 81) patients showed that CA-patients were older (61.1yrs ± 9.3) than H-patients (45.2yrs ± 11.9; p < 0.0001; Student's t-test); had a lower educational level (p = 0.0095); and lower number of sexual partners (p = 0.0222; Fisher's exact test). All groups showed a significant correlation between smoking and lack of HPV-DNA-positivity (p = 0.001). Further Fisher's exact tests and logistic regression analysis revealed in all 106 patients no significant correlations between tissue-HPV-status and the analyzed parameters. Despite the limited sample size, we were able to confirm the established correlation between smoking and tissue-HPV-status. The correlation between sexual behavior and HPV-infection was not confirmed. No consensus exists in the literature about the latter. Our data does not support the strict classification of oral HPV-infections and HPV-driven HNSCCs as STDs.

Induction chemotherapy with paclitaxel and cisplatin followed by radiotherapy for larynx organ preservation in advanced laryngeal and hypopharyngeal cancer offers moderate late toxicity outcome (DeLOS-I-trial).

A prospective multicenter phase-II trial (12 centers) was performed by the German larynx organ preservation group (DeLOS) to evaluate the effect of induction chemotherapy (ICHT) with paclitaxel/cisplatin (TP), followed by accelerated-hyperfractionated (concomitant boost) radiotherapy (RT) in responders. The trial was focused on larynx preservation, tumor control, survival, salvage surgery and late toxicity in patients with advanced larynx/hypopharynx carcinoma eligible for total laryngectomy (LE). Seventy-one patients (40 larynx, 87.5% St. III, IV; 31 hypopharynx, 93.4% St. III, IV) were enrolled into the study and treated with ICHT (200 mg/m(2) paclitaxel, 100 mg/m(2) cisplatin; day 1, 22) according to the DeLOS protocol. Patients with complete or partial tumor response proceeded to RT (69.9 Gy in 5.5 weeks). Non-responders received a LE followed by postoperative RT (56-70 Gy in 5.5-7 weeks). The response rate to ICHT for larynx cancer was 69.6% (7.1% complete, 62.5% partial response) and for hypopharyngeal cancer was 84.3% (6.9% complete, 77.4% partial response). Overall survival after 36 months was 60.3% (95% CI, 48.4-72.2%), after 42 months was 56.5% (95% CI, 44.2-68.8%). Laryngectomy-free survival was as follows: after 36 months, 43.0% (95% CI, 30.9-55.0%); after 42 months, 41.3% (95% CI, 29.3-53.3%). Both parameters did not show different outcomes after distinguishing larynx from hypopharynx. LE was indicated in 15 non-responders after ICHT. Five of the 15 non-responders refused the laryngectomy. Two of the five received RT instead and had no evidence of disease 42 months after RT. Late toxicity (dysphagia III, IV LENT SOMA score in laryngectomy-free survivors: after 6 months, 1.8%; 12 months, 11.4%; 18 months, 14.5%; 24 months, 8.1%; 36 months, 16%) and salvage surgery (4 pharyngocutaneous fistulas in 27 operations) were tolerable. In a large portion of patients eligible for LE, the larynx could be preserved with satisfying functional outcome. Good responders after ICHT had also a good general outcome with relatively rare severe late toxicities. Due to a slight increase of relevant late dysphagia, functional outcome regarding swallowing and tracheotomy free breathing should be more focused in future larynx organ preservation trials.

Saethre-Chotzen syndrome caused by TWIST 1 gene mutations: functional differentiation from Muenke coronal synostosis syndrome.

The Saethre-Chotzen syndrome (SCS) is an autosomal dominant craniosynostosis syndrome with uni- or bilateral coronal synostosis and mild limb deformities. It is caused by loss-of-function mutations of the TWIST 1 gene. In an attempt to delineate functional features separating SCS from Muenke's syndrome, we screened patients presenting with coronal suture synostosis for mutations in the TWIST 1 gene, and for the Pro250Arg mutation in FGFR3. Within a total of 124 independent pedigrees, 39 (71 patients) were identified to carry 25 different mutations of TWIST 1 including 14 novel mutations, to which six whole gene deletions were added. The 71 patients were compared with 42 subjects from 24 pedigrees carrying the Pro250Arg mutation in FGFR3 and 65 subjects from 61 pedigrees without a detectable mutation. Classical SCS associated with a TWIST 1 mutation could be separated phenotypically from the Muenke phenotype on the basis of the following features: low-set frontal hairline, gross ptosis of eyelids, subnormal ear length, dilated parietal foramina, interdigital webbing, and hallux valgus or broad great toe with bifid distal phalanx. Functional differences were even more important: intracranial hypertension as a consequence of early progressive multisutural fusion was a significant problem in SCS only, while mental delay and sensorineural hearing loss were associated with the Muenke's syndrome. Contrary to previous reports, SCS patients with complete loss of one TWIST allele showed normal mental development.

Pseudoaneurysm of the lingual artery after temperature-controlled radiofrequency tongue base reduction: a severe complication.

Temperature-controlled radiofrequency reduction (TCRF) of the tongue base has been developed as an alternative option for the treatment of patients with obstructive sleep apnea syndrome. The technique is propagated as an easy and safe surgical method. The case of a 34-year-old male patient with obstructive sleep apnea syndrome who underwent TCRF is reported. Fourteen days after surgery was performed, heavy bleeding at the base of the tongue occurred. Computed tomography and digital subtraction angiography imaging revealed a pseudoaneurysm of the lingual artery, which was treated endovascularly by detachable and free platinum coils during the same session. The article reports the first case of pseudoaneurysm under TCRF of the tongue base and discusses the diagnostic and therapeutic procedure to handle and avoid life-threatening complications under this method of treatment.

The antileukoprotease secretory leukocyte protease inhibitor (SLPI) and its role in the prevention of HPV-infections in head and neck squamous cell carcinoma.

Recently, we demonstrated a significant inverse correlation between HPV-infection and SLPI-expression suggesting that SLPI protects against HPV-infection of HNSCC. Here we analyzed in a single lab setting 307 formalin-fixed paraffin-embedded HNSCC cases (tonsillar n = 135; non-tonsillar: n = 172) from eight health care centers. Samples were analyzed for SLPI gene- and protein-expression. Annexin A2, its heterotetramer A2t, putatively facilitating HPV- and SLPI-cell entry, was measured to study the correlation between SLPI and annexin A2. Data were correlated with tobacco consumption and HPV-status. Overall, HPV-DNA prevalence was 23.5% (72/307); attributed to: 43.7% (59/135) tonsillar and 7.6% (13/172) non-tonsillar cases. Smoking resulted in 6.44-fold increased and HPV-infection in 3.46-fold decreased SLPI-gene expression in all HNSCC with similar significant results obtained in tonsillar and non-tonsillar SCC separately. Correlating annexin A2- and SLPI-gene expression showed a significant surplus of annexin A2 in HPV-positive tumors (4.21× more annexin A2) and 6.72× more annexin A2 than SLPI in nonsmokers in all HNSCCs and similar significant results for both tumor entities separately. The surplus of annexin A2 in non-smokers and HPV-positive patients supports our hypothesis that decreased SLPI levels facilitate HPV-infection i.e., increased SLPI-expression may protect against HPV-infection of tonsillar and non-tonsillar SCC.

Geographical and anatomical influences on human papillomavirus prevalence diversity in head and neck squamous cell carcinoma in Germany.

The increased knowledge regarding HPV-infections in head and neck squamous cell carcinoma (HNSCC) has unexpectedly contributed to several uncertainties related to i) prevalence diversities depending on tumour site and geographical origin of the patients, ii) proportion of HPV-driven tumours among HPV-DNA-positive cases, and iii) identification of patients with HPV-attributed survival benefit. To investigate this heterogeneity, we analysed 307 HNSCC cases (tonsillar, n=135; non-tonsillar, n=172) from eight health care centers mostly from Northern Germany and determined HPV-DNA/mRNA and p16INK4A-status and combined results with the patient outcome. Overall HPV-DNA prevalence rate was 23.5% (72/307); attributed to: 43.7% (59/135) and 7.6% (13/172) tonsillar and non-tonsillar cases, respectively. Among these, 96.6% tonsillar and 38.5% non-tonsillar SCC were HPV-mRNA-positive. Although the study cohort was composed of patients from regions of rather close proximity, prevalence rates showed diversities of up to 40% in HNSCC subsite analysis with the lowest prevalence for tonsillar SCC in metropolitan areas (22.2%) vs. 50.9% in rural areas. Survival analysis identified p16INK4A alone as strongest predictor, followed by HPV-DNA-status alone or in combination with p16INK4A. This survival benefit was shown for tonsillar and non-tonsillar cases. Smoking significantly correlated with HPV-status, however, it does not influence survival when stratified for HPV. In conclusion, the data emphasize the urge for further data on HPV-infection in HNSCC to, e.g. clarify to what extent survival benefits of p16INK4A-positive patients are truly attributed to HPV-infections.

Induction chemotherapy with paclitaxel and cisplatin and CT-based 3D radiotherapy in patients with advanced laryngeal and hypopharyngeal carcinomas--a possibility for organ preservation.

BACKGROUND: To evaluate the effect of paclitaxel/cisplatin induction chemotherapy (ICHT) and CT-based radiotherapy (RT) on larynx preservation, tumor control, and survival in patients with larynx/hypopharynx carcinoma eligible for total laryngectomy (TL) or TL plus partial pharyngectomy (TLPP). PATIENTS AND METHODS: Fifty patients eligible for TL or TLPP were enrolled onto a prospective study and treated with ICHT (200 mg/m(2) paclitaxel, 100 mg/m(2) cisplatin; day 1, 22). In patients with complete or partial tumor response RT (69.9 Gy in 5.5 weeks at the gross tumor, 50.4 Gy in the lymphatic drainage; single dose: 1.8 Gy, concomitant boost: 1.5 Gy) was applied. Non-responders had TL/TLPP and RT with total doses adapted to the radicality of tumor resection (56-70 Gy). RESULTS: The response rate to ICHT was 88% (10% complete, 78% partial response). At a median follow-up period of 25 months the larynx preservation rate was 84%. The 2-year local-regional control rate was 91% and the 2-year overall survival rate was 72.3%. The 3-year estimate to survive with functional larynx is 60%. CONCLUSION: In a large portion of patients eligible for TL or TLPP the larynx was preserved by paclitaxel/cisplatin ICHT and 3D RT.

Expression of bone morphogenetic protein-2 messenger ribonucleic acid in cholesteatoma fibroblasts.

HYPOTHESIS: The aim of the study was to evaluate the role of bone morphogenetic protein-2 (BMP-2) in the pathology of middle ear cholesteatoma. BACKGROUND: Middle ear cholesteatoma is a chronic inflammatory disease associated with destruction of the temporal bone and marked by increased expression levels of diverse cytokines. Bone remodeling associated with this disease is mainly caused by the action of osteoclasts. It has been shown that BMP-2 expression is inducible by interleukin 1 in synovial fibroblasts and that BMP-2 in combination with interleukin 1alpha is able to stimulate the formation of osteoclast-like multinucleated cells in co-cultures of osteoblast-like cells and hematopoietic cells. METHODS: By using Northern hybridizations, we examined the messenger ribonucleic acid expression of BMP-2 in keratinocytes and fibroblasts derived from normal external ear canal skin (EACS) and from cholesteatoma, respectively. RESULTS: We show that normal EACS fibroblasts do not express BMP-2, whereas keratinocytes of both EACS and cholesteatoma origin are positive for the BMP-2 transcript. In contrast to EACS fibroblasts, BMP-2 is clearly expressed in cholesteatoma perimatrix fibroblasts. Incubation of normal fibroblasts with cholesteatoma extracts caused the transcription of BMP-2. Interleukin 1alpha, bacterial endotoxin, or bovine keratin, however, were not able to initiate BMP-2 expression in normal fibroblasts. CONCLUSION: In view of the above data, it is tempting to speculate that BMP-2 expression might play a role in cholesteatoma pathology.

Predictors of listening capabilities and patient satisfaction after stapes surgery in otosclerosis.

OBJECTIVE: To study objective or subjective preoperative factors predicting improvement in listening capabilities and patient satisfaction after stapes surgery in otosclerosis. STUDY DESIGN: Prospective, multicenter study. SETTING: Two tertiary referral centers. PATIENTS: Fifty-four consecutive adult patients with otosclerosis. INTERVENTIONS: Stapedotomy, stapedectomy. MAIN OUTCOME MEASURES: Pure tone and speech audiometry and questionnaires were assessed preoperatively and repeated 6 months postoperatively. The questionnaires consisted of a visual analogue scale (VAS, 0-10) to score the overall quality of life, and the Operation Benefit Profile to assess the listening capability in various circumstances. Stereophony, defined by the Belfast rule of thumb, was used to divide the patients in 3 categories having unilateral, symmetric bilateral, or asymmetric bilateral hearing loss. RESULTS: Six patients were considered early failures of surgery, and 8 patients were lost to follow-up. In the remaining 40 patients (43 ears), all audiometric parameters improved significantly. The postoperative air-bone gap was less than 10 dB in 70%. The postoperative average air conduction threshold was less than 30 dB in 49%. The postoperative quality of life was excellent (VAS, ≥9) in 45% and did not correlate with any preoperative parameter. Preoperative and postoperative overall listening capabilities correlated slightly (Spearman r, 0.47). The postoperative VAS correlated with all postoperative audiometric parameters and the Operation Benefit Profile. CONCLUSION: Uncomplicated stapes surgery itself is the only predictor of improvement in listening capabilities and patient satisfaction 6 months after stapes surgery in otosclerosis.

Differential gene expression in a paclitaxel-resistant clone of a head and neck cancer cell line.

The anti-neoplastic drug paclitaxel (taxol), which is known to block cells in the G2/M phase of the cell cycle through stabilization of microtubules, is meanwhile commonly used for chemotherapy of advanced head and neck cancer. Chemotherapy is primarily used in order to preserve laryngeal and/or pharyngeal structures. Although paclitaxel generally seems to be a powerful agent, it failed to reach a loco-regional tumor control in a sufficient percentage of patients. In order to investigate molecular resistance mechanisms, we have established a paclitaxel-resistant subline originating from the larynx carcinoma cell line HLaC79, which seemed to be partially dependent on taxol. The original and the descendant cell line were characterized by growth inhibition assays. We used western blotting and the cDNA subtraction (SSH) technique to identify genes differentially expressed in the taxol-resistant cell clone. cDNA subtraction revealed increased expression of six genes, including clathrin heavy chain, alpha3-tubulin, a neuroblastoma-specific Thymosin beta, the ribosomal protein L7a, HLA-B associated transcript 3 and collagen IIIalpha1 in the taxol-resistant cell line. Furthermore, western blots showed an overexpression of MDR-1 in the taxol-resistant clone, while alpha- and beta-tubulins and p48/IRF9 were expressed in equal amounts in both cell lines.

Hyperfractionated accelerated radiotherapy in combination with weekly cisplatin for locally advanced head and neck cancer.

BACKGROUND: The purpose of this study was to determine the feasibility and efficacy of hyperfractionated accelerated radiotherapy (HFRCB) combined with simultaneous chemotherapy with weekly cisplatin (CDDP) in locally advanced inoperable head and neck cancer. METHODS: From August 1999 to December 2002, 37 patients (median age, 59 years) with Union Internationale Contre le Cancer stage III (n = 2) and stage IV (n = 35) squamous cell cancer of the oropharynx and hypopharynx were treated in a prospective phase I/II trial. Concomitant boost radiotherapy (1.8 Gy, days 1-38 and 1.5 Gy boost, days 22-38, twice daily with at least a 6-hour interval; total dose 69.9 Gy) and simultaneous cisplatin, 40 mg/m2 weekly, were given. RESULTS: The median treatment duration was 42 days (range, 38-46 days). Toxicity was manageable, with neutropenia grade III/IV and thrombocytopenia grade IV in seven and one patients, and mucositis grade III/ IV in 27 and five patients, respectively. Chemotherapy was restricted to four weekly applications in 29 patients mainly because of mucosal toxicity with a median dose intensity of 160 mg/m2 (0-200) of cisplatin in 5.5 weeks. With a median follow-up of 28 months for living patients, the 2-year overall survival rate was 67%. The median overall and relapse-free survival times were 36 and 31 months, respectively. CONCLUSION: HFRCB in combination with weekly cisplatin achieves a high rate of locoregional control and survival. Four weekly cycles of 40 mg/m2 cisplatin seem to be the dose limit for most patients.

Tumor volume as determined by computed tomography predicts local control in hypopharyngeal squamous cell carcinoma treated with primary surgery.

Computed tomography reliably evaluates hypopharyngeal squamous cell carcinomas (SCC) regarding the infiltration of specific anatomic structures and tumor volumes, both of which have been shown to be predictors of local control in patients treated with radiation therapy alone. However, an association of specific infiltrated structures and/or tumor volume with local control has not been investigated for surgical treatment; thus, we determined relationships of various infiltrated anatomic structures and tumor volume with local control in patients with hypopharyngeal SCC treated with primary surgery. In 45 hypopharyngeal SCC, tumor volumes were measured by pretreatment CT, and extent of tumor infiltration was determined by postoperative pathologic examination. All patients had clinical follow-up for recurrent tumor at the primary site. Statistical analysis basically consisted of chi-square and U-tests. Local control rate was 84.4% (38 of 45). Tumor volume was significantly associated with local control (p=0.004). Six of 16 (38%) patients with tumor volumes > or =8.1 cm3 (mean) had a local recurrence, which is significantly (p=0.003) more compared with 1 of 29 (3%) in the group of patients with volumes <8.1 cm3. Among all evaluated anatomic structures, only a tendency for significant association with local control was found for tumor involvement of the tonsils and the extralaryngeal soft tissues. The determination of tumor volumes by CT helps predict local control in patients with hypopharyngeal SCC treated with primary surgery.

CT determination of lymphocytic infiltration around head and neck squamous cell carcinomas may be a predictor of lymph node metastases.

The histological detection of a peritumoral lymphocytic infiltration (PLI) and a sharp tumor border in patients with squamous cell carcinoma (SCC) of the larynx, pharynx or oral cavity is inversely correlated with the development of cervical lymph node metastases and is therefore a favorable prognostic factor. However, preoperative biopsies are often too small for an evaluation of these tumor features. Here, we examined retrospectively whether elevation of peritumoral density values as determined by contrast-enhanced computed tomography (CT) correlates with PLI and the presence of cervical lymph node metastases. A total of 40 patients with primarily resected SCC were studied (pT1=8, pT2=13, pT3=9, pT4=10); 25 patients were pN-positive. All tumors were histologically analyzed regarding PLI (present or not) and the tumor border (sharp or infiltrating). Based on standardized CT examinations (90 ml contrast agent at 1.5 ml/s), repeated region-of-interest (ROI)-based peritumoral density measurements were obtained. Correlations between CT density, PLI, tumor border and metastatic involvement of regional lymph nodes were statistically evaluated. CT densities were significantly higher (P<0.001) in patients with PLI and sharp tumor borders than in patients without PLI and patients with infiltrating tumor borders. Moreover, the presence of PLI, sharp tumor borders and elevated peritumoral CT densities were each correlated with the absence of lymph node metastases (P<0.001). An elevation of peritumoral CT densities is linked to PLI and sharp tumor borders on histology and a lower risk to develop lymph node metastases. For a patient-adapted therapy, these relations have to be prospectively evaluated regarding their prognostic relevance.

Inducible promoters for gene therapy of head and neck cancer: an in vitro study.

The aim of gene therapy includes the tight spatial and temporal control of transgenic expression. There are several approaches concerning externally inducible gene promoters used for the control of suicide genes. Two of the promoters that might play a role in head and neck cancer gene therapy are the hyperthermia-inducible human heat shock protein-70 (hsp70) promotor, as well as the radiation-inducible promoter of the early growth response-1 gene (egr-1). We tested the hsp-70 promoter as well as a promoter construct, containing synthetic radio-responsive elements of the egr-1 enhancer for the effect on reporter gene expression in two stably transfected head and neck carcinoma cell lines in vitro and measured the success of gene activation by FACS analysis, western blot analysis and fluorescence microscopy. With the hsp70 promoter we reached a 5.83-fold increase of reporter gene expression after hyperthermic treatment in one of the two cell lines tested. The radiation-inducible construct revealed only weak gene induction and was marked by high background expression. Both systems worked in a highly cell-type dependent manner. The possible clinical use of externally inducible transgene expression in head and neck carcinoma gene therapy is critically discussed.