Inhibition of microflora associated with oral malignancy

Changes in the microflora on oral carcinoma surfaces may lead to both local and systemic infections, which may complicate the morbidity of the patient suffering from oral malignant neoplasms. Thus, anticancer therapy, irradiation, chemotherapy or surgery impairs the defence mechanism of the oral mucosa and is accompanied by proliferation of the mucosal biofilm with overgrowth of yeast and bacteria. This study investigates the inhibition of the biofilm present on the surface of oral squamous cell carcinomas. Biofilm samples were obtained from the central surface (1 cm2) of each lesion in 10 patients (eight male, two female; mean age: 47.6 years; SD +/- 7.6) before any antibiotherapy or tumour treatment. Patients were randomly divided into two groups and were rinsed with Meridol mouthrinse (amine fluoride) or placebo (saline solution) for 7 days. Samples were repeatedly taken from the same site after rinsing. Samples were transported in pre-reduced brain heart infusion broth and cultured within 1 h of removal, using aerobic and anaerobic complete and selective media. Total aerobic and anaerobic counts were determined and isolated bacteria were identified. The median counts of colony forming units (CFU/ml) after rinsing with Meridol were significantly lower for both aerobes and anaerobes than before rinsing with Meridol. (For aerobes before rinsing: 1.35 x 10(6), after rinsing: 7.55 x 10(5); p = 0.025; for anaerobes before rinsing: 1.39 x 10(6), after rinsing: 7.15 x 10(5); p = 0.011. Rinsing with placebo: no significant difference was found. Aerobe median counts before rinsing: 1.17 x 10(6), after rinsing: 1.03 x 10(5), and for anaerobes: before rinsing 1.75 x 10(6), after rinsing: 1.51 x 10(6); p > 0.05 [Wilcoxon test].) It was concluded that 7-days (three times a day) Meridol rinsing significantly reduced the surface biofilm of oral carcinoma compared to rinsing with placebo. Clinical examination indicated no irritation of the mucosa. The mouthrinse was well tolerated by the patients, who commented on a reduction in burning sensation and bad breath. Besides routine oral hygiene, rinsing itself could reduce patient morbidity. The findings of the present study indicate that in addition to any other oral focus, the lesion itself, when ulcerated, should receive direct antimicrobial treatment so as to reduce patient morbidity and enhance quality of life.     

Overexpression of cyclooxygenase-2 is associated with radioresistance in oral squamous cell carcinoma

Cyclooxygenase-2 (COX-2), an inducible isoform of cyclooxygenase, is overexpressed in many types of malignant tumors, which in turn may stimulate tumor growth and protect against damage by irradiation or cytotoxic agents. The purpose of this study is to investigate the relationship between the radiation sensitivity and elevated level of COX-2. Radiation sensitivity of the eight oral SCC cell lines differed greatly in their response to radiation. Further, the level of the COX-2 expression correlated inversely with increased tumor radiation sensitivity. The similar significant association between the response to preoperative radiation therapy and COX-2 overexpression was observed in the oral SCC patients. In addition, treatment with a COX-2 selective inhibitor enhanced the radioresponse of HSC-2 cell, which constitutively expressed COX-2. These results suggested that COX-2 expression level correlates to radiation tolerance and the COX-2 selective inhibitor may be a potent enhancer for tumor radioresponse in oral SCC.     

In vitro transformation of rat bladder epithelium by 2-amino-4-(5-nitro-2-furyl)thiazole

To establish a rat urinary bladder carcinogenesis model in vitro, primary rat bladder epithelial cells were grown in media containing 2-amino-4-(5-nitro-2-furyl)thiazole (ANFT), the water-soluble metabolite of N-[4-(5-nitro-2-furyl)-2-thiazolyl]-formamide (FANFT), for 4 weeks followed by long-term (4-7 months) exposure to control medium, sodium saccharin (NaS), or urea. Another set of cultures were exposed to ANFT, NaS and urea simultaneously. Several phenotypic changes were observed in the chemically exposed cell cultures, namely differences in cell morphology, increased growth rate and the ability to grow on plastic instead of rat-tail collagen support. All of the chemically exposed cultures were anchorage independent except one of those treated with NaS. The ANFT-treated cells followed by control medium or urea and cells treated with ANFT, NaS and urea were tumorigenic when transplanted to nude mice, whereas NaS or ANFT followed by NaS treatment were not. The tumors were carcinomas and their epithelial differentiation was verified by strong positive staining for cytokeratin. These studies demonstrate the urothelial transforming capability of ANFT in cell culture without the necessity for a long exposure to a secondary chemical.     

Overexpression of SENP5 in oral squamous cell carcinoma and its association with differentiation

Small ubiquitin-like modifiers (SUMOs) play an important role in tumors. The SUMOylation can be reversed by SUMO-specific proteases (SENPs). As one of the crucial members of the SUMO system, SENP5 is essential in mitosis and/or cytokinesis. In the present study, we analyzed the expression of SENP5 in human oral squamous cell carcinoma and investigated the relationship between its expression level and clinicopathological parameters. Expression levels of SENP5 in 48 patients with oral squamous cell carcinoma were investigated by immunohistochemistry. Immunoreactivity was evaluated semiquantitatively using German immunoreactive score (IRS). The relationship between SENP5 expression status and the clinical and pathological characteristics of patients was analyzed and survival curves were calculated using the Kaplan-Meier method and log-rank tests. We found that SENP5 predominantly localized to cytoplasm of OSCC cells and the expression of SENP5 in OSCC is not the same as in paracarcinoma epithelia. The SENP5 expression status was associated with differentiation of OSCC and not with any other clinicopathological parameters. These findings suggest altered subcellular localization of SENP5 in OSCC cells and the correlation between SENP5 expression and the differentiation of OSCC.     

Overexpression of beta2-microglobulin is associated with poor survival in patients with oral cavity squamous cell carcinoma and contributes to oral cancer cell migration and invasion

beta2-Microglobulin (beta2M), a component of MHC class I molecules, is believed to be associated with tumour status in various cancers. In this study, we examined the expression of beta2M at different malignant stages of oral cavity squamous cell carcinoma (OCSCC). To determine the possible correlation between beta2M expression and various clinical characteristics, 256 samples from patients with OCSCC were evaluated by immunohistochemical staining. Strong beta2M expression was significantly correlated with a relatively advanced tumour stage (P<0.001), positive nodal status (P<0.001), and TNM stage (P<0.001). The cumulative 5-year survival rate was significantly correlated with a relatively advanced tumour stage (P<0.001), positive nodal status (P<0.001), TNM stage (P<0.001), and strong expression of beta2M (P<0.001). Thus, elevated beta2M expression is an indicator of poor survival (P<0.001). In addition, we extended our analysis of beta2M expression to the FaDu and SCC25 oral cancer cell lines. beta2-Microglobulin expression was positively correlated with cell migration and invasion in beta2M-overexpressing transfectants in Transwell chambers. The suppression of beta2M expression using small interfering RNA (siRNA) was sufficient to decrease cell migration and invasion in vitro. Taken together, our results suggest that beta2M expression in the tissues is associated with survival and may be involved in tumour progression and metastasis in OCSCC.     

Carcinogenicity of 2-amino-4-(5-nitro-2-furyl)thiazole in rats by oral and subcutaneous administration

Female Fischer rats were divided into two groups and fed eitherbasal diet or basal diet containing 0.166% 2-amino-4-(5-nitro-2-furyl)thiazolefor 52 weeks followed by basal diet for an additional 16 weeks.Out of the 24 rats fed 2-amino-4-(5-nitro-2-furyl)thiazole,23 had forestomach tumors, four had fibroadenomas and two hadadenocarcinomas in the mammary glands, two had renal pelviccarcinomas, five had papillomas and six had carcinomas in thebladder, and two had cutaneous tumors. None of the 10 rats fedbasal diet developed tumors. In another study, two-week-oldFischer rats of both sexes were injected s.c. once a week forthe first eight weeks with 2-amino-4-(5-nitro-2-furyl)thiazoleat a dose of 10 mg/kg and then 1.4 mg/rat for an additional46 weeks. The control rats were injected with solvent (dimethylsulfoxide:water, 1: 1) only. The experiment was terminated atthe end of 58 weeks. Malignant fibrous histiocytomas were foundin five out of eight male rats and four out of 11 female rats,and an angiosarcoma was found in one out of eight male ratsinjected with 2-amino-4-(5-nitro-2-furyl)thiazole. None of thecontrol rats developed tumors.     

Neoplasms associated with paraneoplastic pemphigus: a review with emphasis on non-hematologic malignancy and oral mucosal manifestations

The review included 163 cases of paraneoplastic pemphigus (PNP) reported between 1990 and 2003, including a new unique case of PNP associated with occult breast cancer and an ovarian cyst of borderline malignancy. Hematologic-related neoplasms or disorders were associated with 84% of the cases, with non-Hodgkin lymphoma (38.6%) as the most frequent, followed by chronic lymphocytic leukemia (18.4%) and Castleman's disease (18.4%). The non-hematologic neoplasms comprised 16% of all cases: epithelial origin-carcinoma (8.6%), mesenchymal origin-sarcoma (6.2%), and malignant melanoma (0.6%). Carcinoma cases comprised 58% of the non-hematologic neoplasms. Carcinoma cases (n = 14) consisted of adenocarcinoma (n = 7), squamous cell carcinoma (n = 2), multiple skin tumors probably basal cell carcinoma (n = 1), and bronchogenic carcinoma (n = 1). Of the 10 (6.2%) sarcoma cases, there was one case each of leiomyosarcoma, liposarcoma, malignant nerve sheath tumor, poorly differentiated sarcoma, reticulum cell sarcoma, dendritic cell sarcoma and inflammatory myofibroblastic tumor. The oral mucosa was involved in all of cases. Isolated oral ulcerations were the first sign in 45% of the cases. Diffuse and persistent oral ulcerations with a progressive course could be a sign of malignancy, either recognized or occult. In the absence of a clear diagnosis, malignancy should be suspected and extensive work-up performed. The full spectrum of signs of PNP may not be present initially. Repeated biopsies, direct and indirect immunofluorescence as well as screening indirect immunofluorescence on murine bladder are required for diagnosis. Clinicians should be highly suspicious when signs and symptoms suggestive of PNP are present in cancer patients, of hematologic and non-hematologic origin.     

Overexpression of HER-2/neu is associated with poor survival in advanced epithelial ovarian cancer

Previous studies have suggested that overexpression of HER-2/neu oncogene occurs in 15-40% of breast cancers and that overexpression is associated with poor prognosis. In the present report, we have used an immunohistochemical technique involving a monoclonal antibody specifically reactive with the external domain of HER-2/neu to study expression of HER-2/neu in frozen sections of normal ovary and advanced epithelial ovarian cancer. The intensity of staining for HER-2neu was always moderate or less (0-2+) in normal ovarian epithelium. Among 73 ovarian cancers, 50 (68%) had staining similar to that for normal ovarian epithelium (0-2+) while 23 (32%) stained heavily (3+). Survival of the 23 patients with high HER-2/neu expression (median, 15.7 months) was significantly worse (P = 0.001) than that of the 50 patients (median, 32.8 months) with normal HER-2/neu expression. In addition, patients whose tumors had high HER-2/neu expression were significantly less likely to have a complete response to primary therapy (P less than 0.05) or have a negative second-look laparotomy when serum CA 125 levels were normal preoperatively (P less than 0.05). These findings suggest that HER-2/neu deserves further evaluation as a prognostic marker in epithelial ovarian cancer.     

Sensitivity test for 5-fluorouracil and its analogues, 1-(2-tetrahydrofuryl)-5-fluorouracil, uracil/1-(2-tetrahydrofuryl)-5-fluorouracil (4:1) and 1-hexylcarbamoyl-5-fluorouracil, using the subrenal capsule assay

The chemosensitivity of 20 human neoplastic tissues including 13 gastric and 7 colorectal cancers was tested using 5-fluorouracil (5-FU) and its analogues: 1-(2-tetrahydrofuryl)-5-FU (FT), uracil/FT (UFT) and 1-hexylcarbamoyl-5-FU (HCFU), and the in vivo subrenal capsule (SRC) assay. The relative variation of tumor size (delta TS/TSo) was calculated as follows: delta TS/TS0 = (TS6-TS0/TS0) x 100%, where TS6 was the tumor size on day 6 and TS0 on day 0, and the chemosensitivity was considered to be sensitive when delta TS/TS0 in the treated group was decreased to below -10%. The mean tumor size was -10.9 +/- (SD) 10.9% for 5-FU, -12.3 +/- 17.1% for FT, -18.4 +/- 15.8% for UFT and -17.9 +/- 15.4% for HCFU. The decrease of tumor size was marked when exposed to UFT (p less than 0.01) or HCFU (p less than 0.02), compared with that to 5-FU. Positive correlations were noted between the tumor sizes of 5-FU and its analogues (5-FU vs. FT, r = 0.851; 5-FU vs. UFT, r = 0.746; 5-FU vs. HCFU, r = 0.685). In 9 tissues resistant to 5-FU, 2 (22%) were sensitive to FT, 4 (44%) to UFT, 5 (56%) to HCFU and 7 tissues (78%) to at least one of these analogues. These results suggest that the SRC assay is useful for predicting the effective drug among 5-FU and 5-FU analogues, for individual patients with cancer.     

Overexpression of cIAP2 contributes to 5-FU resistance and a poor prognosis in oral squamous cell carcinoma

Background:

Resistance to 5-fluorouracil (5-FU) is a major obstacle in treating oral squamous cell carcinoma (OSCC). However, little is known about apoptosis resistance, which contributes to 5-FU resistance in OSCC.

Methods:

We focussed on the cellular inhibitor of apoptosis protein 2 (cIAP2) on the basis of a DNA microarray data using parental and 5-FU-resistant OSCC cell lines. The effects of cIAP2 downregulation on 5-FU sensitivity and apoptosis were evaluated. An immunohistochemical analysis of cIAP2 and related proteins, cIAP1 and X-linked IAP, was performed in 54 OSCC patients who were treated with 5-FU-based chemoradiotherapy and surgery.

Results:

The downregulation of cIAP2 significantly enhanced the sensitivity of the 5-FU-resistant cells to 5-FU, with a significant increase in apoptosis. The immunohistochemical analysis demonstrated a high cIAP2 tumour expression to significantly correlate with the pathological response to chemoradiotherapy. Furthermore, a Cox regression analysis revealed the cIAP2 expression status (hazard ratio, 4.91; P=0.037) and the pathological response to chemoradiotherapy (hazard ratio, 0.418; P=0.016) to be significant prognostic factors for OSCC patients.

Conclusion:

These novel findings demonstrate that cIAP2 may represent a potentially useful therapeutic target for improving the treatment and survival of OSCC patients, particularly in the setting of 5-FU resistance.     

Antitumour action of 1,5-dihalogeno-, and 1, 2-4, 5-dianhydro-xylitol derivatives

The antitumour action of some xylitol compounds possessing alkylating potency at 1 and 5 position of the sugar skeleton was investigated. Unlike the hexitol derivatives, bi-halogenated xylitols showed no antitumour action. The modest therapeutic index of 1, 2-4,5-dianhydroxylitol on the NK/Ly ascites tumour could be substantially increased by the addition of a phenyl-benzoyl group at the 3 position. This latter compound appeared to be active against L1210 leukaemia, S-180, and Yoshida solid sarcoma; and furthermore, against metastasis formation of the Lewis lung tumour.     

Tuberculosis associated with malignancy of the nasopharynx

A case of malignancy and tuberculosis occurring together in the nasopharynx is reported. The relevant literature on the association of these two diseases is reviewed.