Expression of Ricinus communis receptors on epithelial cells in oral carcinomas and oral wounds.
(65/13224)
The histological distribution of receptors for Ricinus communis Fraction 1 (RCA1) in oral carcinomas and in oral epithelial cells during wound healing has been studied by use of fluorescein-tagged RCA1. Biopsies from 15 human oral carcinomas and adjacent normal mucosa showed RCA1 receptors at the cell membranes in the basal and spinous layer of the normal epithelium, whereas receptors could not be demonstrated in invading islands of the tumors. In healing oral wounds from eight humans and three monkeys, RCA1 receptors were demonstrated both in normal epithelium adjacent to the wounds and in the epithelial outgrowth from the wound margin. Titrations, however, showed that the epithelial outgrowth reacted more weakly than did the normal adjacent epithelium. These results support previous in vitro studies showing changes in carbohydrate composition of moving normal cells and of malignant cells, a finding that may be of interest in relation to formation of metastases. (+info)
Lymphoscintigraphy in tumors of the head and neck using double tracer technique.
(66/13224)
Knowledge of possible lymphatic drainage may facilitate planning of surgery for patients with head and neck tumors. Therefore, the aim of this study was to present a method of lymphoscintigraphy with special attention to an accurate correlation of lymphatic drainage to anatomic regions. METHODS: Lymphoscintigraphy was performed using a double tracer technique before surgery in a total of 75 patients with squamous cell carcinoma of the head and neck. All patients received 100 MBq 99mTc-colloid at three to four peritumoral sites. A perchlorate solution (2 mL) was given orally to block salivary glands and the thyroid gland. Patients received 50 MBq 99mTc-pertechnetate intravenously for body contouring 20 min postinjection. Planar images were obtained over 5 min each, at 30 min and 4 h postinjection from anterior, right lateral and left lateral views with a large-field-of-view gamma camera. Lymphatic drainage was assessed by visual inspection and assigned to six cervical compartments. RESULTS: Neither the salivary glands nor the thyroid gland were seen in any of the patients. In 22 of 75 patients (29.3%), the injection site was the only focal tracer uptake seen. In contrast, lymphatic drainage was identified in the remaining 53 patients (70.7%), and lymph nodes could be assigned easily to the six cervical compartments. Of 75 patients, 36 (48%) exhibited ipsilateral lymphatic drainage. In addition, 17 patients (22.7%) with unilateral tumor showed bilateral (n = 12), contralateral (n = 2) or retropharyngeal (n = 3) lymphatic drainage. In 3 of these 17 patients, bilateral lymph node metastases were proven. A subgroup of 12 patients (16%) exhibited N2c nodal status, despite a unilateral localized primary tumor. In 3 of these 12 patients, surgery was extended as a result of scintigraphic findings from unilateral toward bilateral neck dissection, and histology confirmed nodal involvement in these patients. CONCLUSION: Lymphoscintigraphy using the double tracer technique allows an accurate correlation of lymphatic drainage to the six cervical compartments. This may provide the basis for a re-evaluation of its impact in treatment planning of patients with head and neck tumors. (+info)
Retinoic acid is able to induce interferon regulatory factor 1 in squamous carcinoma cells via a STAT-1 independent signalling pathway.
(67/13224)
Interferon regulatory factor 1 (IRF-1) transcription factor binds to DNA sequence elements found in the promoters of type I IFN and IFN-inducible genes. Transient up-regulation of the IRF-1 gene by virus and IFN treatment causes the consequent induction of many IFN-inducible genes involved in cell growth control and apoptosis. We reported recently that IFN-alpha and all-trans retinoic Acid (RA) inhibit the cell proliferation of squamous carcinoma cell line ME-180 by inducing apoptotic cell death. IRF-1 expression correlates with the IFN-alpha-induced apoptosis phenomenon and, surprisingly, with the RA-induced apoptosis phenomenon. To study how these two different ligands cross-talk in the regulation of cellular antitumor responses, the signalling pathways involved in IRF-1 induction were analyzed in RA and/or IFN-alpha-treated ME-180 cells. We provide evidence indicating that RA-induced IRF-1 gene expression is independent of the STAT-1 activation pathway, despite the presence of the IFN-gamma activated sequence element in the gene promoter, but involves nuclear factor-kappaB activation. Thus, here we first describe the activation of nuclear factor-kappaB by both IFN-alpha and RA in the ME-180 cell line. The induced IRF-1 protein is successively able to bind the IFN-stimulated responsive element in the promoter of the target gene 2',5'-oligoadenylate synthetase. (+info)
Overriding of cyclin-dependent kinase inhibitors by high and low risk human papillomavirus types: evidence for an in vivo role in cervical lesions.
(68/13224)
High risk types of human papillomavirus (HPV) are agents in the aetiology of cervical carcinoma. The products of two early genes, E6 and E7, appear to be the principal transforming proteins. Studies of various monolayer cell culture systems have shown that the E7 oncoprotein of human papillomavirus type 16 is able to neutralize or bypass the inhibitory effect of the cell cycle-dependent kinase (CDK) inhibitors (CKIs) p21WAF1/CIP1 and p27KIP1. To understand whether the p21WAF1/CIP1 or p27KIP1 neutralization also plays a role in vivo, we performed studies on clinical specimens. Forty-five cervical biopsies, including HPV-negative mucosa, HPV 16-positive preinvasive (low and high grade lesions) and invasive neoplasia as well as HPV 6-positive condyloma acuminatum were analysed by single and double immunohistology. We examined the positive cell cycle regulator cyclin A and the universal cell cycle marker Ki67 as well as the negative cell cycle regulators p21WAF1/CIP1 and p27KIP1. Here, we show that in a significant fraction of cells the G1 block can be overcome despite high levels of CKIs in HPV lesions. This phenomenon, which was more evident for p21WAF1/CIP1 than for p27KIP1 was most marked in low grade lesions and in condylomata acuminata, in which a high viral productivity is expected. These results indicate that the overriding of CKI inactivation by viral oncoproteins appears to be a conserved property between low and high risk HPV types. We conclude that the CKI neutralization by HPVs is likely to be required for viral DNA replication rather than for malignant transformation of the host cell. (+info)
Dendritic cell differentiation pathways of CD34+ cells from the peripheral blood of head and neck cancer patients.
(69/13224)
Patients with head and neck squamous cell carcinoma (HNSCC) have increased levels of immune-suppressive peripheral blood CD34+ cells. This study showed that the peripheral blood CD34+ cells of HNSCC patients are capable of differentiating into dendritic cells. Because CD34+ cells can differentiate through several pathways into dendritic cell subpopulations, the intermediate cells through which the blood CD34+ cells of HNSCC patients differentiate were identified. After 6-7 days of culturing the CD34+ cells of HNSCC patients with granulocyte-macrophage colony-stimulating factor, stem cell factor, and tumor necrosis factor at, there appeared CD14+CD1a+ and a lesser proportion of CD14(-)CD1a+ cells resembling the precursor cells of the bipotential and committed dendritic cell differentiation pathways that have been described for cord blood CD34+ cells. To functionally analyze whether these populations were in fact precursor cells, they were isolated and cultured for an additional 10-12 days. Each of these populations was shown to function as precursor cells because they were able to develop into cells that resembled dendritic cells, although a higher proportion developed from the CD14-CD1a+ cells. In contrast, expression of the dendritic activation/maturation marker CD83 was highest on the cells that developed from CD14+CD1a+ cells. Thus, the CD34+ cells whose levels are increased in HNSCC patients can develop into both committed and bipotential dendritic precursor cells, which can subsequently give rise to dendritic cells. (+info)
Randomized comparison of fluorouracil plus cisplatin versus hydroxyurea as an adjunct to radiation therapy in stage IIB-IVA carcinoma of the cervix with negative para-aortic lymph nodes: a Gynecologic Oncology Group and Southwest Oncology Group study.
(70/13224)
PURPOSE: In 1986, a protocol comparing primary radiation therapy (RT) plus hydroxyurea (HU) to irradiation plus fluorouracil (5-FU) and cisplatin (CF) was activated by the Gynecologic Oncology Group (GOG) for the treatment of patients with locally advanced cervical carcinoma. The goals were to determine the superior chemoradiation regimen and to quantitate the relative toxicities. METHODS: All patients had biopsy-proven invasive squamous cell carcinoma, adenocarcinoma, or adenosquamous carcinoma of the uterine cervix. Patients underwent standard clinical staging studies and their tumors were found to be International Federation of Gynaecology and Obstetrics stages IIB, III, or IVA. Negative cytologic washings and para-aortic lymph nodes were required for entry. Patients were randomized to receive either standard whole pelvic RT with concurrent 5-FU infusion and bolus CF or the same RT plus oral HU. RESULTS: Of 388 randomized patients, 368 were eligible; 177 were randomized to CF and 191 to HU. Adverse effects were predominantly hematologic or gastrointestinal in both regimens. Severe or life-threatening leukopenia was more common in the HU group (24%) than in the CF group (4%). The difference in progression-free survival (PFS) was statistically significant in favor of the CF group (P = .033). The sites of progression in the two treatment groups were not substantially different. Survival was significantly better for the patients randomized to CF (P = .018). CONCLUSION: This study demonstrates that for patients with locally advanced carcinoma of the cervix, the combination of 5-FU and CF with RT offers patients better PFS and overall survival than HU, and with manageable toxicity. (+info)
Head and neck cancer: altered fractionation schedules.
(71/13224)
Local control is paramount in the treatment of localized advanced head and neck cancer. Standard radiotherapy cures a high percentage of early tumors--more than 80% of the early laryngeal tumors--but fewer of the advanced tumors. Attempts have therefore been made to improve the therapeutic ratio by: A) hyperfractionation: reducing the dose per fraction to reduce late morbidity; the total dose is then elevated in an attempt to improve local tumor control with equal morbidity, and B) acceleration: reducing the overall treatment time to overcome repopulation during a protracted course of radiotherapy. The total dose and dose per fraction have been reduced in the accelerated arm in some trials, while in others the total dose has been maintained. Both these strategies have been tested in multicenter randomized controlled trials, but neither have become part of routine clinical practice. The biological parameters determining local tumor control and normal tissue effects are being studied at Mount Vernon by an analysis of selected randomized controlled trials, with the aim of designing new schedules of radiotherapy for future studies. (+info)
Predictive value of malignancy grading systems, DNA content, p53, and angiogenesis for stage I tongue carcinomas.
(72/13224)
AIM: To assess the clinical value of malignancy grading systems compared with nuclear DNA content, protein p53, and angiogenesis for predicting recurrence of stage I (UICC, 1987) tongue carcinomas. METHODS: Histopathological malignancy grading according to Jakobsson and tumour front grading according to Bryne et al were performed on haematoxylin and eosin slides. DNA analysis was performed by image cytometry. Protein p53 and angiogenesis were evaluated by immunohistochemical analysis using antibody CM1 and antibody against factor VIII related antigen, respectively. RESULTS: 49 patients with stage I carcinomas of the mobile tongue were included, all treated by local surgical excision alone. Eight patients (16%) suffered from local recurrence during follow up, and 13 (27%) had regional recurrence. Both Jakobsson's malignancy grading system and p53 immunoreactivity proved to be useful predictors of regional recurrence in a Cox multivariate regression analysis. CONCLUSIONS: Histopathological malignancy grading systems provide valuable prognostic information and can still compete with current biological markers in this respect. (+info)