Human papillomavirus (HPV) infections are related to the genesis of various benign and malignant human neoplasias. The HPV types 16 and 18 seem to be causally related to the development of most squamous cell carcinoma of the anogenital tract and a proportion of carcinomas of the upper aerodigestive tract. The near 100% positivity of the HPV types 6 and 11 in laryngeal papillomatosis is well established. We investigated whether HPV also plays a role in non-neoplastic mucosal entities such as sinunasal polyposis, the genesis of which has been discussed as being triggered by viral infections. On DNA from 39 sinunasal polyps (33 patients), polymerase chain reaction (PCR) was performed using beta-globin primers for demonstration of amplifiable DNA in the tissue extracts. Consensus primers for the detection of several different HPV types were applied to the beta-globin-positive samples. The results were confirmed by Southern blot hybridization using consensus probes. Cycle sequencing was performed on the positive cases. All 39 samples showed positive signals for beta-globin. HPV-DNA investigations showed a slight positive signal in only 1 of the 39 investigated cases (2.6%). Further molecular investigations of this sample, including cycle sequencing, could not confirm this result. All the other tissue samples remained HPV-DNA-negative. Therefore, those HPV types readily detectable with the PCR primers and probes used are not frequently associated with sinunasal polyposis. The data confirm the hypothesis that HPV is correlated to a lesser extent to infectious mucosal lesions than to proliferative lesions. Furthermore, the results emphasize that the presence of HPV in specific lesions does not occur by chance, but represents a specific infection of the mucosa leading to proliferation and even to malignancy.
p53 antibodies are a new serological parameter of unknown potential in patients with malignancies. Their occurrence has been described in various types of cancer patients. The mechanism underlying the immunization process is still unclear. We investigated the incidence of p53 serum antibodies in 143 head and neck cancer patients with an enzyme-linked immunosorbent assay. The posttherapy course of two matched study groups (n = 38 each), one p53-antibody-seropositive and one p53-antibody-seronegative, was followed up for 24 months. Thirty-nine head and neck cancer patients (27.3%) were seropositive for p53 antibodies. During the follow-up, the p53-antibody-seropositive patients accounted for more local tumor recurrences (n = 12 versus n = 8) and more tumor-related deaths (n = 11 versus n = 5) than did seronegative patients, and second primary tumors (n = 9 versus n = 0) occurred exclusively in seropositive patients. In total, therapy failures (recurrences, tumor-related deaths, second primaries) were observed in 17/38 cases (44.7%) in the p53-antibody-seropositive group and in 8/38 cases (21.1%) in the p53-antibody-seronegative group. These results, after a follow-up of 2 years, seem to indicate a prognostic value of p53 serum antibodies for therapy failure in patients with head and neck cancer.
Human papillomaviruses (HPV) are discussed as cofactors in the carcinogenesis of squamous cell carcinoma of the head and neck (SCCHN). The prevalence of HPV infection in SCCHN is the subject of controversy since reported HPV prevalences range from less than 10% to almost 100%, depending mainly on the detection method employed. This study presents a realistic approximation to the real prevalence of HPV in SSCHN by applying polymerase chain reaction (PCR) and Southern blot hybridization (SBH), which are the most sensitive and specific HPV detection methods. Diagnostic procedures were optimized by applying a "hot-start" PCR protocol followed by a confirmatory SBH of the PCR products to reactions using both type-specific and consensus primers and probes. DNA of 75 tumour samples and 22 normal mucosa samples of the same patients were investigated. In 14 cases genomic SBH using complete HPV genomes as probes was performed additionally. HPV DNA was detected in 17/75 (22.7%) SCCHN specimens. HPV 16 was identified in four cases, HPV 45 in three cases, and HPV 6 and 18 in one case each. Hot-start PCR and SBH are the most reliable HPV detection methods, as they minimize both false-positive and false-negative results. With these methods, a HPV prevalence of 23% was achieved, which can be assumed to be representative for comparable study populations. The significant number of positives detected only by consensus primer PCR, along with the identification of HPV 45, indicate that further HPV types may play an important role in the genesis of SCCHN.
Carcinogenesis is considered a multistep process. To further elucidate involved genetic changes, the differential display method was applied to compare gene expression of head and neck carcinoma cells and normal keratinocytes from the upper aerodigestive tract. Total RNA was extracted from cultured squamous carcinoma cells and keratinocytes. mRNA was reverse transcribed into cDNA, amplified by PCR, and separated on a gel. Currently three DNA transcripts were identified with a length of 191 to 336 base pairs (bp) that were either expressed only by the keratinocytes or by the malignant cells. Differentially expressed DNA fragments of the carcinoma cells and the keratinocytes were cloned and sequenced. A gene bank database search identified one fragment expressed by the carcinoma cells as an unknown gene, another one found in the keratinocytes as probably a part of the human cell attachment domain, and the third one with homology to the mRNA of the human epidermal growth factor receptor (EGFR). Northern blot analysis confirmed the differential expression in the malignant cells or the keratinocytes. Differential display seems to confirm the well-known overexpression and up-regulation of the EGFR, the differential expression of the cell attachment domain may play a role as a cofactor in carcinogenesis of head and neck cancer, and the third unknown fragment is still under investigation to elucidate the role in carcinogenesis.
Volume 117 Number 2Research Forum --Tuesday P 131 say using a human tongue SCC line, BroTo, was treated with a combination of chemotherapy and the MAb to the EGFr. Methods:The present investigators, using flow cytometry, determined that the EGFr MAb could bind to the cell line, BroTo. BroTo cells were then cultured in a 24-well tissue culture plate at a concentration of 5 x 104 cells per well.One hour later either control media or 1.25 pg/ml of cisplatin (Cis) were added to the cells. After 4 hours cells were washed with PBS and either control media, MAb to the EGFr, and/ or 5-fluorouracil (5-FU) were added. A viability test was then performed at 24, 48, and 72 hours and the number of live cells was counted.Results: After a 72-hour incubation, the cells exposed to both Cis and 5:FU exhibited 17.3% of the control cell concentration. However, ceils exposed to EGFr MAb, Cis, and 5-FU demonstrated 12.57% viable cells compared with the control at 72 hours. Comparatively these two groups were significantly different from each other with ap value of 0.002 using a two-tailed t test. Conclusion:These findings suggest the possible augmentation of the activity of the chemotherapeutic drugs when in the presence of MAb to the EGFr. Mechanisms for this occurrence are currently being elucidated and will be discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.