Interleukin-1 beta in unstimulated whole saliva is a potential biomarker for oral squamous cell carcinoma

The objective of this study was to evaluate cytokines in unstimulated whole saliva (UWS) of oral squamous cell carcinoma (OSCC) patients as compared to those with pre- and post-operation for evaluation as markers of OSCC. Sixteen OSCC patients were included in this study. Cytokine concentrations in resting saliva were measured using a Bio-Plex suspension array system. Only interleukin-1 (IL-1) beta showed significantly different cytokine concentration in saliva between pre- and post-operation. IL-1 beta was released from cultured OSCC cells confirmed by ELISA and immunohistochemistry. From this study, IL-1 beta in UWS may be useful for detection of early stage OSCC. More studies are needed to accept the utility of IL-1 beta in UWS for predicting, diagnosis and evaluation of OSCC.

Multicenter phase II trial of preoperative chemoradiotherapy with S-1 for locally advanced oral squamous cell carcinoma

Purpose

We evaluated whether preoperative chemotherapy with S-1 and concurrent radiotherapy is feasible and efficacious in the treatment of advanced oral squamous cell carcinoma.

Methods

Participants comprised 39 patients with oral carcinoma (stage III, n = 15; stage IVA, n = 24). All patients received a total radiation dose of 40 Gy, in once-daily 2-Gy fractions, and received S-1 at 65 mg/m²/day for 5 consecutive days, over 4 consecutive weeks with concurrent radiotherapy.

Results

Hematological toxicity was mild and reversible. The most common non-hematological toxicity was grade 3 mucositis, but this was transient and tolerable. Radical surgery was performed for 37 patients, with the remaining 2 patients declining the surgery. Postoperatively, local failure developed in 1 patient, and neck failure in 2 patients. Distant metastases were identified in 4 patients. At a median follow-up of 38.0 months (range 23–88 months), locoregional control, disease-specific survival, and overall survival rates at 3 years were 91.5, 83.8, and 83.8 %, respectively.

Conclusion

Concurrent administration of S-1 and radiotherapy combined with surgery offers a well-tolerated method of successfully treating advanced oral squamous cell carcinoma. The locoregional control rate remains high even at 3 years of follow-up, and no serious adverse effects have been encountered.

Medical emergency education using a robot patient in a dental setting

INTRODUCTION

In an ageing society, the frequency of medical emergencies in a dental setting appears to be increasing because of a growing number of medically compromised patients. However, we currently have no dental-specific simulation environment with advanced reproducibility for medical emergencies. Therefore, we used the robot patient in objective structured clinical examinations (OSCEs) for testing student competence in emergency management. This study aimed to evaluate student responses to medical emergencies in the dental setting.

MATERIAL AND METHODS

We used 98 fifth-grade dental students at Showa University as subjects and implemented the OSCE task entitled 'Management of medical emergency using a robot patient'. Candidates were asked to manage an emergency situation immediately after local anaesthesia, with one robot patient configured to develop vasovagal syncope and the other to experience adrenaline hypersensitivity. A questionnaire on the educational value of the robot patient was completed after the examination.

RESULTS

Thirty-two per cent of students could not accurately count her pulse because of an inappropriate method. Moreover, 78% could not correctly attach either the tonometer or pulse oximetry to the patient. Accurate diagnoses were given by only 22% of students, with vasovagal syncope diagnosed by 33% and adrenaline hypersensitivity by 8%. From a questionnaire, 78% of students recognised the usefulness of the robot patient in medical emergency training.

CONCLUSION

We found that student responses to the emergency situation were poor. The robot patient is useful in dental education for medical emergency training and assessment not only for situation management but also for differential diagnosis.

The potential anticancer activity of extracts derived from the roots of Scutellaria baicalensis on human oral squamous cell carcinoma cells

Various herb products derived from plants have potent biological effects including anticancer activity. In the present study, the antitumor activity of a herbal product derived from the Scutellaria baicalensis (S. baicalensis) was examined, using in vitro assays in a human oral squamous cell carcinoma (OSCC) cell line. Results showed that S. baicalensis root extract at the concentration of 100 μg/ml inhibited monolayer- and anchorage-independent growth in human OSCC cell lines, while not affecting the adhering abilities of cells. This suggested that it did not alter the expression of any of the adhesion receptors that mediate cell-extracellular matrix (ECM) interactions. The S. baicalensis root extract demonstrated potent cytostatic and apoptotic effects due to the downregulation of the cyclin-dependent kinase 4 expression and its partner cyclin D1, resulting in G1 arrest and poly (ADP-ribose) polymerase (PARP) cleavage. Additionally, the S. baicalensis root extract was found to have blocked vascular endothelial growth factor (VEGF)-induced migration and tube formation in human endothelial cells. Taken together, these results demonstrate that as a herbal product, the S. baicalensis root extract is a potential inhibitor of tumori- and angiogenesis and may be valuable in the development of pharmaceutical medications for the treatment of oral squamous cell carcinoma.

Binding of glyceraldehyde-3-phosphate dehydrogenase to the cis-acting element of structure-anchored repression in ccn2 mRNA

CCN2/connective tissue growth factor (CTGF) can be induced by hypoxia and promotes tumor angiogenesis. Our previous studies revealed that hypoxia-induced gene expression of human ccn2 mRNA is regulated post-transcriptionally in human chondrosarcoma-derived cell line, HCS-2/8, in which a minimal cis-element, entitled CAESAR, in the 3'-untranslated region (UTR) of ccn2 mRNA and a 35-kDa protein counterpart play an important role by determining the stability of ccn2 mRNA. In the present study, we identified this corresponding protein as glyceraldehyde-3-phosphate dehydrogenase (GAPDH) by utilizing RNA affinity chromatography combined with mass spectrometry. The results of an RNA binding assay revealed the specific binding of GAPDH to this cis-element. To further characterize the interaction between GAPDH and ccn2 mRNA, we examined the roles of redox conditions and glycolytic coenzyme in the binding of GAPDH to the ccn2 mRNA. An oxidizing agent, diamide, abolished the GAPDH-RNA interaction in a concentration-dependent manner; whereas this effect could be reversed by subsequent treatment with 2-mercaptoethanol (2-ME). In addition, nicotinamide-adenine dinucleotide (NAD), a coenzyme of GAPDH, inhibited the GAPDH-RNA binding. Taken together, these findings suggest that the glycolytic enzyme GAPDH regulates the gene expression of ccn2 mRNA in trans by acting as a sensor of oxidative stress and redox signals, leading to CCN2 overexpression under the condition of hypoxia and promotion of angiogenesis.

Bone destruction by invading oral squamous carcinoma cells mediated by the transforming growth factor-beta signalling pathway

BACKGROUND

Gingival squamous cell carcinoma (SCC) cells frequently invade mandibular bone, and this destruction is associated with a worse prognosis. However, the relationship between bone destruction and associated factors is unclear. In this study, the role and diagnostic utility of transforming growth factor-beta (TGF-beta) type I receptor (TbetaRI) in bone destruction of the mandible was investigated.

PATIENTS AND METHODS

The expression of TbetaRI was explored by using an immunohistochemical method on paraffin-embedded tissues from 21 cases of mandibular SCC. An inhibitor of the kinase activity of the TbetaRI (TbetaRI-I) was used to assess the role of TbetaRI in bone destruction by a human oral SCC cell line (HSC-2) that highly expresses TbetaRI.

RESULTS

TbetaRI-positive signals were closely associated with destructive invasion of the mandible by oral SCC cells. Consistent with these results, TbetaRI-I greatly reduced HSC-2 cell-induced bone destruction and osteoclast formation in vivo and in vitro. TbetaRI-I treatment reduced the expression of TNF-alpha, RANKL and connective tissue growth factor (CTGF/CCN2), all of which were up-regulated by TGF-beta in HSC-2 cells.

CONCLUSION

These data demonstrated an important role for TGF-beta signalling in bone invasion by oral SCC cells, and suggest that the bone destruction is mediated by RANKL, TNF-alpha and CCN2.

Identification of CCDC62-2 as a novel cancer/testis antigen and its immunogenicity

Cancer/testis (CT) antigens are expressed in normal germ line tissues and various cancers. They are considered promising target molecules for immunotherapy for patients with various cancers. To identify CT antigens, we performed serological identification of antigens by recombinant expression cloning. The humoral immune response of cancer patients against a newly defined antigen was analyzed. A testicular cDNA library was immunoscreened with serum obtained from a gastric adenocarcinoma patient whose primary cancer had regressed once and most liver metastases had disappeared transiently. We isolated 55 positive cDNA clones comprising 23 different genes. They included 4 genes with testis-specific expression profiles in the Unigene database, including coiled-coil domain containing 62 (CCDC62). RT-PCR analysis showed that the expression of 2 splice variants of CCDC62 was restricted to the testis in normal adult tissues. In malignant tissues, CCDC62 variant 2 (CCDC62-2) was aberrantly expressed in a variety of cancers, including stomach cancer. A serological survey of 191 cancer patients with a range of different cancers by ELISA revealed antibodies to CCDC62-2 in 13 patients, including stomach cancer. None of the 41 healthy donor serum samples were reactive in the same test. The serum reaction against CCDC62-2 was confirmed by western blot. CCDC62-2 is a CT antigen that is immunogenic in cancer patients.

[Two cases of giant metastatic cervical lymphnode from oral cancer responding to concurrent chemoradiotherapy with S-1]

We report two cases of giant metastatic cervical lymphnode from oral squamous cell carcinoma, successfully treated with concurrent chemoradiotherapy with S-1. Case 1 was a 80-year-old male who had an ipsilateral occult neck metastasis(52x46 mm mass)at level IV after surgery of the left tongue carcinoma(T2N0M0). Radiotherapy(2.0 Gy/day; 5 days/week)was given at a total dose of 66 Gy. Two courses of oral administration of S-1(61 mg/m2/day)for 2 weeks followed by 1-week rest period as one course was repeated with the concurrent radiotherapy. After the radiotherapy, the oral administration of S-1 alone was continued for 1 year under the same regimen. Case 2 was a 51-year-old male who had left tongue carcinoma(T4bN2cM0)with ipsilateral cervical lymphnode metastasis(88x44 mm mass). The same chemoradiotherapy(1.8 Gy/day; 5 days/week; a total dose of 63 Gy; S-1 53 mg/m2/day)was carried out as in case 1. These giant metastatic lymphnodes of case 1 and 2 disappeared by 3 and 6 months after radiotherapy, respectively, and achieved a complete response. This therapy may be effective not only for primary lesion of oral cancer, but also metastatic regional lymphnodes in some cases.

Clinical significance and pathogenic function of connective tissue growth factor (CTGF/CCN2) in osteolytic mandibular squamous cell carcinoma

BACKGROUND

Mandibular bone destruction is a frequent occurrence in oral squamous cell carcinoma. However, the relationship between the bone destruction and associated factors is unclear. Here, the role and diagnostic utility of connective tissue growth factor (CCN2) in bone destruction of the mandible was investigated.

PATIENTS AND METHODS

The production of CCN2 was explored by using immunohistochemistry on paraffin-embedded tissues from 20 cases of mandibular squamous cell carcinoma. The effect of CCN2 on osteoclastogenesis was examined in vitro by using total bone marrow cell populations from male mice.

RESULTS

Immunohistochemical analysis showed that CCN2-positive signals were closely associated with destructive invasion of the mandible by oral squamous cell carcinomas. Consistent with these results, recombinant human CCN2 (rCCN2) stimulated tartrate-resistant acid phosphatase (TRAP)-positive osteoclast-like cell formation in vitro.

CONCLUSION

CCN2 can be considered a diagnostic marker and target for treatment in oral osteolytic mandibular squamous cell carcinoma.

[A case of acute respiratory distress syndrome (ARDS) induced by docetaxel administration for lung metastases from oral cancer]

We reported a case of acute respiratory distress syndrome (ARDS) induced by docetaxel in treating lung metastases from oral cancer. The patient was an 84-year-old man who had undergone partial mandibulectomy and radical neck dissection for lower gingival carcinoma. The patient developed ARDS after docetaxel administration (40 mg/body) for multiple lung metastases.

An immunohistochemical evaluation of BMP-2, -4, osteopontin, osteocalcin and PCNA between ossifying fibromas of the jaws and peripheral cemento-ossifying fibromas on the gingiva

The present study examined histological difference between ossifying fibromas (OF, n=5) and peripheral cemento-ossifying fibromas (PCOF, n=7). Bone morphogenetic proteins (BMP)-2 and -4, osteopontin (OPN), osteocalcin (OCN) and proliferating cell nuclear antigen (PCNA) were used for the immunohistochemical examinations. Oxytalan fibers present at the periodontal tissue were stained to determine the tumor cell origin. Many OFs showed high immunohistochemical reactions for BMP-2, -4 and OPN compared to those of PCOFs. PCNA index (IP) of OFs was significantly higher than that of PCOFs. All the PCOFs showed a high expression of oxytalan fibers. Only two OFs exhibited a small number of oxytalan fibers. These results suggest that PCOF has only little ability to form hard tissue and seems to be a reactive lesion. The expression of oxytalan fibers reveals that OF does not only originate from periodontal tissue.

Expression of vascular endothelial growth factor-C predicts regional lymph node metastasis in early oral squamous cell carcinoma

The purpose of this study was to investigate the association of the expression of vascular endothelial growth factor-C (VEGF-C) with regional lymph node metastasis in oral squamous cell carcinoma (OSCC). The expression of VEGF-C in biopsy specimens obtained from 62 patients with OSCC was examined by immunohistochemistry. In the early stages of T1 and T2 (38 cases), VEGF-C expression strongly correlated with lymph node metastasis (P < 0.001), and the percentage of VEGF-C-positive staining was 88.2% for patients with lymph node metastasis (15 of 17 cases) and 28.6% for those without lymph node metastasis (6 of 21 cases). However, in the advanced stages of T3 and T4, no significant correlation between VEGF-C expression and lymph node metastasis was observed. These results indicate that VEGF-C expression in biopsy specimens can be used as a reliable predictor of regional lymph node metastasis, particularly in early OSCC, and may become an important factor in the selection of appropriate treatment.

Prognostic significance of heat shock protein 27 (HSP27) in patients with oral squamous cell carcinoma

Heat shock proteins (HSPs) have been defined as proteins induced by heat shock and other environmental and pathophysiologic stress. Heat shock protein 27 (HSP27) is one of the small heat shock proteins. HSP27 is implicated in protein-protein interactions such as folding, translocation, and prevention of inappropriate protein aggregation. Many of their functions suggest that they play important roles in cancers. Archival tissues from 40 patients with oral squamous cell carcinoma who received primary surgical resection were examined for HSP27 by immunohistochemistry and correlated with clinical stage, lymph node metastasis, histological grade and survival period. HSP27 expression was positive staining (+) in 20 (50%), weak or negative staining (-) in 20 (50%) of total 40 cases. There was no correlation between HSP27 expression and clinical stage, lymph node metastasis and histological grade. However, when compared with clinicopathological features, the expression of HSP27 correlated inversely with survival period. This study suggests that the expression of HSP27 is frequently promoted in patients with oral squamous cell carcinoma and should be considered an independent prognostic factor of oral squamous cell carcinoma patients.

Prognostic significance of heat shock protein 27 (HSP27) in patients with oral squamous cell carcinoma

Heat shock proteins (HSPs) have been defined as proteins induced by heat shock and other environmental and pathophysiologic stress. Heat shock protein 27 (HSP27) is one of the small heat shock proteins. HSP27 is implicated in protein-protein interactions such as folding, translocation, and prevention of inappropriate protein aggregation. Many of their functions suggest that they play important roles in cancers. Archival tissues from 40 patients with oral squamous cell carcinoma who received primary surgical resection were examined for HSP27 by immunohistochemistry and correlated with clinical stage, lymph node metastasis, histological grade and survival period. HSP27 expression was positive staining (+) in 20 (50%), weak or negative staining (-) in 20 (50%) of total 40 cases. There was no correlation between HSP27 expression and clinical stage, lymph node metastasis and histological grade. However, when compared with clinicopathological features, the expression of HSP27 correlated inversely with survival period. This study suggests that the expression of HSP27 is frequently promoted in patients with oral squamous cell carcinoma and should be considered an independent prognostic factor of oral squamous cell carcinoma patients.

The usefulness of intraoral ultrasonography in the evaluation of oral cancer

Many studies focused on the tumour thickness in oral squamous cell carcinomas, suggesting a relationship with the occurrence of cervical metastasis. Accurate preoperative assessment of the tumour thickness of oral cancer would provide useful information for targeting those patients who need elective treatment of the neck. Some useful diagnostic aids to evaluate oral cancer are computed tomography (CT), magnetic resonance imaging (MRI), and intraoral ultrasonography. The purpose of the present study is to compare intraoral ultrasonography with CT and MRI in delineating the disease extent and in measuring the tumour thickness of oral carcinoma. Thirty-nine patients with oral cancer were preoperatively evaluated with intraoral ultrasonography, and CT, and in 26 of them MRI was carried out. High-quality ultrasonographic images were obtained and the tumour thickness was measured within 1 mm. However, in most tumours less than 5.0 mm in thickness, CT and MRI could not detect a sufficient density difference from the normal tissue to accurately delineate the extent of the tumour. There was a significant correlation between measurements by intraoral ultrasonography and the histological sections. The present study shows that ultrasonography is superior to CT and MRI in assessment of the primary lesion of oral carcinoma.

The influence of blood arterial oxygen condition on the tumor response to preoperative radiation therapy in oral cancer patients

The relationship between clinicopathological factors and response of radiation therapy in oral squamous cell carcinoma has been studied. It has been suggested that factors such as tumor site, extent and tumor differentiation determine the response to radiation therapy. It is known that oxygenation is related to the therapeutic effects of radiation therapy. However, there are few reports on the relationship between oxygen condition and the response to radiation therapy. The present study was carried out to assess whether any clinicopathological factors, including an evaluation of the oxygen condition can be used to predict the effects of preoperative radiation therapy in oral squamous cell carcinomas. Forty-seven patients with oral cancer treated with external radiation therapy preoperatively were evaluated. There were no significant differences in response to the radiation with respect to age, sex, tumor site, stage, macroscopic shape of tumors, and the histological factors. The hemoglobin (Hb) and arterial oxygen content (CaO(2)) levels of favorable cases (Hb: 14.4 g/dl, CaO(2) 19.1 ml/dl) were significantly higher than those of unfavorable cases (Hb: 11.0 g/dl, CaO(2): 16.1 ml/dl). These findings suggest that oxygen conditions of oral cancer patients predict tumor response to preoperative radiation therapy.

Apoptosis and p53 are associated with effect of preoperative radiation in oral squamous cell carcinomas

This study was carried out to elucidate whether apoptosis and p53 can be used to stratify oral cancer patients into groups with a favorable or unfavorable response to preoperative radiation therapy. Thirty-two patients were evaluated. The apoptosis index was 1.7+/-0. 9% in the ineffective cases, and it was significantly lower than effective cases (3.2+/-1.2%). While 14 of 16 effective cases (86.7%) did not express p53, 13 of 16 ineffective cases (81.3%) overexpressed p53. These results suggest that mutated p53 in tumors is associated with a poor response to radiation which may be related to evasion of apoptosis in oral cancer.

Infrequent alternations of RB pathway (Rb-p16INK4A-cyclinD1) in adenoid cystic carcinoma of salivary glands

Retinoblastoma (Rb) tumor suppressor genes' products and of the proteins regulating its phosphorylation and function in G1 arrest, p16INK4A and cyclin D1, play important roles in the regulation of the cell cycle. Rb gene inactivation, reflected by the absence of Rb protein expression, has been reported in oral squamous cell carcinomas. p16INK4A is frequently deleted, methylated, or mutated, and cyclin D1 gene amplification in many malignancies including oral squamous cell carcinomas (SCC). These findings suggested that Rb pathway of G1 arrest are the most commonly affected genes in Oral SCC. However, alternation of Rb pathway in salivary gland tumors was not clear. In this study, the expressions of Rb, p16INK4A, and cyclin D1 alternations were analyzed by immunohistochemical assay in 5 specimens of normal salivary glands and twenty-two cases of adenoid cystic carcinomas (ACC). Proliferating cell nuclear antigen (PCNA) labelling index (P.I.) was used for the evaluation of cell proliferation. Rb was consistently expressed in normal salivary glands and ACC. Loss of p16INK4A expression was observed in three cases (13.6%) of ACC. And overexpression of cyclin D1 was observed in four cases (18.2%). The three p16INK4A absent cases were the tumors with predominantly solid pattern and those cases were overexpressed cyclin D1. The cell proliferation activities of p16INK4A absent tumors (P.I. = 24.2 +/- 2.1%) were significantly higher than those of p16INK4A present tumors (P.I. = 10.4 +/- 3.5%) (P < 0.05). Cyclin D1 expression was also related to cell proliferation (P.I. of cyclin D1 negative cases vs. cyclin D1 positive: 10.1 +/- 3.0% vs. 22.6 +/- 3.4%) (P < 0.05). These findings suggested, however, alternations of Rb pathway were infrequent events in ACC of salivary glands and inactivation of p16INK4A, cyclin D1 overexpression may be related to the high cell proliferating activity of ACC.

p53 and MDM2 expression in oral squamous cell carcinoma

The p53 tumor suppressor gene is the most commonly mutated gene in human cancer and is a frequent abnormality in oral squamous cell carcinoma and its precancerous lesions. MDM2 (murine double minute-2), a new proto-oncogene, may be associated with p53 gene products and may negatively affect the transcriptional activating function of p53. The purpose of this study was to investigate the incidence of MDM2 and its relationship to the expression of p53 in oral squamous cell carcinoma and precancerous lesions. Overexpression of p53 and MDM2 proteins was detected in 52 and 40% of oral squamous cell carcinomas, respectively. p53 gene mutation, absent in normal oral epithelium was observed in 31% of the carcinoma cases. Our finding suggested that MDM2 protein may be an alternative mechanism causing p53 protein dysfunction in oral squamous cell carcinoma.

Sequential expression of myc-, ras-, oncogene products and EGF receptor during DMBA-induced tongue carcinogenesis

The mechanism leading to development of oral cancer has not been completely understood. It is currently believed that alternation of a number of genes can result in the development of epidermoid carcinomas. In this investigation, we used a 9,10-dimethyl 1,2-benzanthracene (DMBA)-induced carcinogenesis in a hamster tongue model to investigate the expression of c-myc, c-Ha-ms proteins and epidermal growth factor receptor (EGFr). During the DMBA-carcinogenesis of the tongue, the number of c-myc protein positive cells were increased in epithelial dysplasia and elevated throughout the process of tumorigenesis. The expression of c-Ha-ras protein was detected in normal epithelium. The level of c-Ha-ras protein expression was decreased in the dysplastic stage, and it was almost negative in squamous cell carcinomas. Detection of EGFr overexpression occurred only after 1-4 weeks of DMBA treatment, at a very early stage of tumor development, and increased through carcinogenesis varying individually within the malignant tissues. These results suggest that c-myc protein and c-Ha-ras protein expression may have an important role in malignant transformation, and the overexpression of EGFr can be correlated to very early stages of tumor development in the DMBA-induced in vivo tongue carcinogenesis.

Expression of c-erbB family gene products in adenoid cystic carcinoma of salivary glands: an immunohistochemical study

The tyrosine kinase receptor family, including the epidermal growth factor receptor (EGF-R), c-erbB2 and, more recently, the c-erbB3, has been recognized as being of particular importance in many human malignancies. This study was undertaken to define the role of c-erb B2 and c-erbB3 in adenoid cystic carcinomas (A.C.C.) of the salivary glands. Sixteen cases of A.C.C. were studied immunohistochemically, using antibodies against each erbB gene family product. EGF-R was not detected in any of these samples but c-erbB2 and c-erbB3 gene products (ERBB2and ERBB3) were demonstrated in all A.C.C. sections with some degree of straining. Tubular and cribriform patterns overexpressed particularly large amounts of ERBB2 and ERBB3. Strong staining was mainly demonstrated in tumor cells of the invasive area. These results suggested that overexpression of ERBB2 and ERBB3 is related to tumor differentiation and invasion in adenoid cystic carcinomas.

Prognostic significance of ERBB3 overexpression in oral squamous cell carcinoma

Immunohistochemical analysis of erbB3, as the third member of epidermal growth factor receptor gene family, was performed on 41 cases of oral squamous cell carcinoma, correlating the staining pattern with clinical outcome. High expression of erbB3 protein (ERBB3) was significantly associated with lymph node metastasis (P < 0.05), survival rate (P < 0.05) and mode of invasion (P < 0.01) in this series. These results demonstrated that ERBB3 expression may be helpful in identifying those oral squamous cell carcinomas with higher malignant potential.

Cell proliferation and tumor angiogenesis in oral squamous cell carcinoma

Cell proliferation and vascularization play an important role in the metabolic functions of normal and malignant tissues. Tumor cell proliferation and density of microvessels (DM) in 33 specimens of oral squamous cell carcinoma (SCC) were assessed by immunohistochemical staining of proliferating nuclear cell antigen (PCNA) and JC/70A, respectively. Their staining patterns were compared to the clinicopathologic findings. The PCNA labeling index (LI) showed significantly higher values in advanced carcinomas (T3 and T4) (mean, 20.19 +/- 12.79) than in early carcinomas (T1 and T2) (mean, 9.58 +/- 4.01; P < 0.01). The DM (mean, 105.92 +/- 22.65) and PCNA LI (mean, 25.69 +/- 13.32) of tumors with lymph node metastasis were significantly higher than in tumors without nodal involvement (DM, mean, 72.6 +/- 24.30; P < 0.01) (PCNA LI, mean, 10.25 +/- 3.99; P < 0.001). Marginal DM values were significantly correlated and directly proportional to the mode of tumor invasion. Evaluation of PCNA and DM at the periphery of the tumor may help to identify oral SCC that have higher malignant potential.

Overexpression of p53 is an early event in the tumorigenesis of oral squamous cell carcinomas

The purpose of this study was to determine the timing of p53 overexpression during the development of oral squamous cell carcinomas. Immunohistochemical analysis of p53 expression was performed on 107 cases of oral squamous cell carcinoma, 37 cases of leukoplakia, and 10 cases of cancer-free patient's normal oral mucosa samples. 43 of the 107 (40.2%) oral squamous cell carcinomas showed p53 overexpression. There was no relationship between p53-overexpression and clinicopathological factors, such as size of tumors, lymph node metastasis, hostological differentiation and prognosis. Overexpression of p53 was not detected in 10 normal mucosa. Seven out of 37 (18.7%) samples of leukoplakia and 15 out of 43 (34.8%) samples of noncancerous epithelium adjacent to the p53-positive carcinomas showed p53 overexpression, the results demonstrate that p53 protein may have an important role in the early stages of oral tumorigenesis.