Reduced E-cadherin expression correlates with increased invasiveness in colorectal carcinoma cell lines

A reduction in cell adhesiveness and cell invasion are essential steps in tumour progression to metastasis. In the present study two out of seven colorectal carcinoma cell lines exhibited reduced expression of the cell-cell adhesion molecule E-cadherin as assessed by immunofluorescence. The same two cell lines were invasive in the collagen gel and membrane invasion culture system invasion assays. Addition of anti-E-cadherin antibody to a non-invasive carcinoma cell line caused the cells to assume a dissociated morphology on plastic and to become invasive in collagen gels. This demonstrates a causal role for E-cadherin in the maintenance of intercellular adhesion and the suppression of tumour cell invasion and possibly metastasis in colorectal tumour cells.     

E-cadherin regulates anchorage-independent growth and survival in oral squamous cell carcinoma cells

Integrin-basement membrane interactions provide essential signals that promote survival and growth of epithelial cells, whereas loss of such adhesions triggers programmed cell death. We found that HSC-3 human squamous carcinoma cells survived and grew readily as monolayers, but when they were suspended as single cells, they ceased proliferating and entered into the apoptotic death pathway, characterized by DNA fragmentation. In contrast, if the suspended carcinoma cells were permitted to form E-cadherin-mediated multicellular aggregates, they not only survived but proliferated. However, aggregated normal keratinocytes were unable to survive in suspension culture and rapidly became apoptotic. Anchorage independence and resistance to apoptosis of HSC-3 cell aggregates required high levels of extracellular Ca2+ and was inhibited with function-perturbing anti-E-cadherin antibody. Resistance to suspension-induced apoptosis in cell aggregates paralleled the up-regulation of Bcl-2 but occurred in the absence of focal adhesion kinase activation. Analysis of suspension-induced death in a set of cloned squamous epithelial cell lines with different levels of E-cadherin expression revealed that receptor-positive cell clones evaded apoptosis and proliferated in three-dimensional aggregate culture, whereas cadherin-negative clones failed to survive. Collectively, these observations indicate that cadherin-mediated intercellular adhesions generate a compensatory mechanism that promotes anchorage-independent growth and suppresses apoptosis.     

Reduced E-cadherin expression correlates with unfavorable prognosis in adenoid cystic carcinoma of salivary glands of the oral cavity

OBJECTIVE: To describe the epidemiology, diagnosis, risk factors, patient impact, and treatment strategies for recurrent Clostridium difficile-associated disease (CDAD). DESIGN: Data were collected as part of a blinded, placebo-controlled clinical trial testing a new combination treatment for recurrent CDAD. Retrospective data regarding prior CDAD episodes were collected from interviews and medical-chart review. Prospective data on the current CDAD episode, risk factors, and recurrence rates were collected during a 2-month follow-up. SETTINGS: National referral study. PARTICIPANTS: Patients with recurrent CDAD. INTERVENTIONS: Treatment with a 10-day course of low-dose (500 mg/d) or high-dose (2 g/d) vancomycin or metronidazole (1 g/d). RESULTS: Recurrent CDAD was found to have a lengthy course involving multiple episodes of diarrhea, abdominal cramping, nausea, and fever. CDAD may recur over several years despite frequent treatment with antibiotics. Recurrence rates were similar regardless of the choice or dose of antibiotic. Recurrent CDAD is not a trivial disease: patients may have multiple episodes (as many as 14), may require hospitalization, and the mean lifetime cost of direct medical care was $10,970 per patient. Fortunately, the disease does not become progressively more severe as the number of episodes increase. Two risk factors predictive for recurrent CDAD were found: increasing age and a decreased quality-of-life score at enrollment. CONCLUSIONS: Recurrent CDAD is a persistent disease that may result in prolonged hospital stays, additional medical costs, and rare serious complications.     

Immunohistochemical study of desmosomes in oral squamous cell carcinoma: correlation with cytokeratin and E-cadherin staining, and with tumour behaviour

Reduction or loss of the intercellular junctions known as desmosomes may contribute to the invasive and metastatic behaviour of various carcinomas. Previous studies have shown that metastasis of oral squamous cell carcinomas of the head and neck correlates with a reduction in immunohistochemical staining for desmoplakin and desmoglein at the invasion front. The primary aim of the present study was to extend these observations to include a third component of desmosomes, the glycoprotein desmocollin. An additional aim was to determine whether the differentiation status of tumours is reflected in their staining for cytokeratins 1, 13, and 19, and, if so, whether these parameters correlate with desmosomal staining and/or metastasis. The study included 54 primary tumours of which 28 showed lymph node metastases. The results of this investigation show that tumours can be divided into three groups according to whether they have lost staining for no, one or more than one desmosomal component. A statistically significant correlation was found between the number of desmosomal components lost and metastasis. Tumours could also be divided into five groups according to their staining for different combinations of cytokeratins. Furthermore, differentiation status as indicated both histologically and by cytokeratin staining correlated with reduced desmosomal staining and metastasis. Tumours were also examined for intensity of staining for the adhesion molecule E-cadherin. Reduction in E-cadherin staining was correlated with mode of invasion and with reduction in desmosomal staining, but not with poor differentiation as indicated by cytokeratin staining. The results of this extensive study reinforce the view that adhesive junctions and adhesion molecules contribute to the suppression of tumour invasion and metastasis.     

Tenascin-C matrix assembly in oral squamous cell carcinoma

We previously showed that the extracellular matrix component tenascin-C (TN-C) is upregulated in oral squamous cell carcinoma (SCC) compared with the normal oral mucosa. In this study we examined oral biopsy specimens of mild to moderate dysplasia or carcinoma in situ to study TN-C expression. We found that carcinoma in situ is the stage at which TN-C becomes widely expressed, suggesting it may be involved in the initial stages of tumor progression. To study TN-C matrix production in vitro, we used an invasive oral SCC cell line (HSC-3) and peri-tumor fibroblasts (PTF). Neither cell type organized a TN-C matrix when cultured alone; however, when co-cultured with HSC-3 cells, PTF were able to assemble a TN-C matrix. PTF retained the ability to organize a TN-C matrix when separated from the HSC-3 cells by a semi-permeable membrane, indicating that cell-cell contact is not necessary for TN-C matrix organization and suggesting that soluble factors may be involved. Moreover, PTF were induced to assemble TN-C matrices when grown in medium conditioned by both the PTF and HSC-3 cells. Antibodies to fibronectin (FN) and to the first FN type III repeat blocked both FN and TN-C matrix assembly, indicating that TN-C matrix organization is dependent on an FN template. Antibodies to alpha5, alphav and beta1 integrins also blocked TN-C matrix formation. When seeded onto FN matrices, the co-cultures were unaffected by the anti-integrin and anti-FN antibodies and were able to organize a TN-C matrix. Our results suggest that progression of malignant oral SCC is accompanied by an alteration of the normal ECM to one rich in TN-C, and that the organization of a TN-C matrix is dependent on soluble cues provided by both the SCC cells and the PTF.     

Cytokeratin expression in squamous cell carcinoma of the lung and oral cavity: an immunohistochemical study with possible clinical relevance

An extramural vessel wall hematoma occurred immediately after implanting a coronary stent in an in-stent-restenosis of the intermedius branch. Angiography showed a significant luminal reduction distal to the intervention site. Intravascular ultrasound revealed an extramural echolucent zone compressing the vessel lumen. Stent implantation compressed the hematoma and allowed adequate myocardial perfusion. This demonstrates the value of intravascular ultrasound (IVUS) in cases of unusual angiographic results which can help to manage complications after coronary intervention.     

Pre-operative radio-chemotherapy enhances apoptotic cell death in oral squamous cell carcinoma

The effect of pre-operative radio-chemotherapy (RCT) has been examined in a total of 15 oral squamous cell carcinomas (SCCs), in terms of apoptosis (cell loss) and proliferation. All the patients received pre-operative radiation at a dosage of 30 or 40 Gy, as well as anticancer agents including tagaful (FT), 5-fluorouracil (5-FU), bleomycin (BLM) and peplomycin (PEP). Surgical specimens were obtained before and after RCT, and serial sections were prepared for immunohistochemistry for p53 oncoprotein and Ki-67 antigen, as well as for terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL). TUNEL indices (TI; percentage of TUNEL-positive cells in the tumor cells) before and after RCT were 1.2+/-1.1 and 4.7+/-2.9 in the nine well-differentiated oral SCCs, and 1.0+/-0.7 and 3.9+/-2.1 in the six poorly differentiated SCCs, respectively. Similarly, Ki-67 indices (KI; percentage of Ki-67 antigen-positive cells in tumor cells) before and after RCT were 31.1+/-14.2 and 15.8+/-11.1 in the former, and 37.1+/-7.8 and 8.7+/- 13.4 in the latter, respectively. Thus, pre-operative RCT enhanced apoptotic cell death and abated proliferative activity significantly (P<0.05), regardless of histological differentiation. Enhancement of apoptosis was more prominent in the group treated with FT or 5-FU than with BLM or PEP. Oral SCC with >20% of nuclear p53-positive tumor cells was noted in six cases. Enhanced TI and abadement of KI did not differ among the p53-positive and -negative tumors.     

Primary oral squamous cell carcinoma: a review of 92 cases

PURPOSE: This is a retrospective review of 92 cases of oral squamous cell carcinoma treated by one department of oral and maxillofacial surgery. PATIENTS AND METHODS: The medical records of 92 patients with oral squamous cell carcinoma were reviewed, and standard epidemiologic data were obtained. In addition, cases were identified as to site, stage, risk behavior, histologic classification, primary and secondary surgical treatment, adjunctive therapy, and survival rates. RESULTS: The results indicate a higher-than-predicted 2-year survival rate. The association between alcohol and tobacco consumption and incidence of disease is supported. There was a correlation between tumor size and survival rate, but no correlation between histologic classification and prognosis. CONCLUSION: Mortality increases in relation to the stage at which the diagnosis of oral squamous cell carcinoma is made. Patients with stage III or IV lesions have a much poorer prognosis than those with stage I or II lesions. However, histologic classification and prognosis were not correlated.     

Fibroblast growth factor receptor expression reflects cellular differentiation in human oral squamous carcinoma cell lines

This study examined the expression of fibroblast growth factor receptor 2 (FGFR 2) splice variants, IIIb and IIIc, in normal and malignant human oral keratinocytes and in normal oral fibroblasts by RT-PCR using both exon-specific primers and primers common to both FGFR 2 isoforms. Fibroblasts expressed exclusively FGFR 2/IIIc whilst the normal and malignant keratinocytes co-expressed FGFR 2/IIIb and FGFR 2/IIIc. Well-differentiated keratinocytes expressed proportionally more FGFR 2/IIIb than IIIc whereas the poorly-differentiated cells expressed more FGFR 2/IIIc than IIIb. The normal and malignant keratinocytes, but not fibroblasts, expressed an additional amplification product, which consisted of both IIIb and IIIc of FGFR 2 joined by an extra base pair and with the intronic sequence removed. The results indicate that the expression of FGFR 2 isoforms reflects the degree of cellular differentiation in normal and malignant human oral keratinocytes and that receptor complexes of FGFR 2/IIIb and IIIc may regulate ligand-receptor interactions.     

Inactivation of p16 in human mammary epithelial cells by CpG island methylation

Proliferation of human mammary epithelial cells (HMEC) is limited to a few passages in culture due to an arrest in G1 termed selection or mortality stage 0, M0. A small number of cells spontaneously escape M0, continue to proliferate in culture, and then enter a second mortality stage, M1, at which they senesce. Evidence that M0 involves the Rb pathway comes from the observation that expression of human papillomavirus type 16 E7 alleviates the M0 proliferation block, and we further show that the Rb-binding region of E7 is required to allow cells to bypass M0. In contrast, E6 does not prevent HMEC from entering M0 but, rather, is involved in M1 bypass. Here we show that inactivation of the D-type cyclin-dependent kinase inhibitor p16INK4A is associated with escape from the M0 proliferation block. Early-passage HMEC express readily detectable amounts of p16 protein, whereas normal or E6-expressing HMEC that escaped M0 expressed markedly reduced amounts of p16 mRNA and protein. This initial reduction of p16 expression was associated with limited methylation of the p16 promoter region CpG island. At later passages, a further reduction in p16 expression occurred, accompanied by increased CpG island methylation. In contrast, reduction of p16 expression did not occur in E7-expressing HMEC that bypassed M0, due to inactivation of Rb. These observations in the E6-expressing HMEC correlate well with the finding that CpG island methylation is a mechanism of p16 inactivation in the development of human tumors, including breast cancer.     

Combination assay for tumor markers in oral squamous cell carcinoma

PURPOSE: This study evaluated use of a combination assay of tumor markers in the diagnosis of oral squamous cell carcinoma. PATIENTS AND METHODS: Serum levels of four tumor markers (carcinoembryonic antigen [CEA], squamous cell carcinoma antigen [SCCA], immunosuppressive acidic protein [IAP], and cytokeratin 19 fragment [Cyfra]) were simultaneously measured in 42 patients with oral squamous cell carcinoma (O-SCC) and in 12 patients with oral benign diseases. RESULTS: The positive rates were 31.0% for CEA, 38.1% for SCCA, 52.4% for IAP, and 38.1% for Cyfra in patients with O-SCC. These rates were significantly different (P < .01) from those of control patients with oral benign diseases. The sensitivity (81.0%) and accuracy (77.8%) of the combination assay uses higher than that obtained with individual markers. CONCLUSION: A combination assay with CEA, SCCA, IAP, and Cyfra may be useful for the screening of patients with suspected oral squamous cell carcinoma.     

Frequent deletion and 5' CpG island methylation of the p16 gene in primary malignant lymphoma of the brain

A total of 10 primary malignant lymphomas of the brain were examined for deletion, mutation, and 5' CpG island methylation of the p16 gene, which is a candidate tumor suppressor gene with CDK-inhibitory function. In Southern blot analysis, p16 gene deletion was suggested in nine cases, homozygously (five cases) or hemizygously (four cases). In the remaining one case, p16 gene deletion was not suggested. Although single-strand conformation polymorphism and nucleotide analyses suggested no mutations of the p16 gene in these cases, methylation analyses revealed 5' CpG island methylation in three cases, of which two were those with presumed hemizygous deletion and one was that without deletion in Southern blot analysis. Thus, p16 gene abnormality was detected in all 10 of the brain lymphomas examined, and in 8 of them, actual p16 gene inactivation was suggested by their homozygous deletion (5 cases) or 5' CpG island methylation (3 cases). These findings suggest that p16 gene abnormality and inactivation are closely related to carcinogenesis in primary malignant lymphoma of the brain. The p15 gene, another candidate tumor suppressor gene located in the vicinity of the p16 gene, to which it shows structural and functional similarity, was also presumed to be deleted similarly in most cases. Its methylation was seen in one case, the case without the methylated p16 gene.     

Distribution and synthesis of type VII collagen in oral squamous cell carcinoma

Modern reproductive techniques and alternative family structures (with single or homosexual parents and adoption situations) raise questions about the consequences for the growing children involved. Genetic links appear to be less important for the functioning of a family than a strong wish for parenthood; parents who have become parents only through great efforts display a better quality of parenthood than average natural parents. Characteristics of the parent/parents, such as paedagogic qualities, and the quality of the parent-child relationship appear more important than the type of family. Published results of research reveal no reason why lesbian families should be judged differently from heterosexual ones as family types for the raising of children. The main negative factor for the functioning of the child growing up in a single-parent family is the marriage conflicts that have led to the single-parent situation; being raised by a single parent in itself has no adverse effect. Raising adopted children from other countries makes far greater demands on the adoptive parents than parents of biological children have to meet. The raising of a foreign adopted child by a single parent entails additional risks for the child's development. Data on the development of children in alternative family structures frequently concern exceptionally competent parents, which may have biased the findings.     

Possible involvement of DNA methylation in 5-azacytidine-induced neuronal cell apoptosis

Firefly luciferase emits a burst of light when the substrates luciferin and ATP are mixed in the presence of oxygen. We (I. Ueda, A. Suzuki, Biophys. J. 75 (1998) 1052-1057) reported that long-chain fatty acids are specific inhibitors of firefly luciferase in competition with luciferin in microM ranges. They increased the thermal transition temperature. In contrast, 1-alkanols of the same carbon chain length inhibited the enzyme non-competitively in mM ranges and decreased the transition temperature. The present study showed that the action of fatty acids switched from specific to non-specific when the carbon chain length was reduced below C8 (octanoate). The fatty acids longer than C10 inhibited the enzyme in microM ranges whereas those shorter than C8 required mM ranges to inhibit it. The longer fatty acids increased whereas shorter fatty acids decreased the transition temperature. The Hill coefficients of longer chain bindings were less than one whereas those of shorter chain were more than one. The shorter fatty acids interacted with the enzyme cooperatively at multiple sites. Binding of the longer fatty acids is limited. Fatty acids longer than C10 are high-affinity specific binders and followed Koshland's induced-fit model. Those shorter than C8 are low-affinity non-specific denaturants and followed Eyring's rate process model. These results contradict the general consensus that the size of the receptor cavity discriminates specific binders.     

p53 antibodies in the saliva of patients with squamous cell carcinoma of the oral cavity

A significant age dependence of the risk of complete heart block complicating radiofrequency ablation of the AV nodal slow pathway was noticed, with no patients <45 years of age experiencing this complication.