Melatonin is a potential drug for the prevention of bone loss during space flight.

Astronauts experience osteoporosis-like loss of bone mass because of microgravity conditions during space flight. To prevent bone loss, they need a riskless and antiresorptive drug. Melatonin is reported to suppress osteoclast function. However, no studies have examined the effects of melatonin on bone metabolism under microgravity conditions. We used goldfish scales as a bone model of coexisting osteoclasts and osteoblasts and demonstrated that mRNA expression level of acetylserotonin O-methyltransferase, an enzyme essential for melatonin synthesis, decreased significantly under microgravity. During space flight, microgravity stimulated osteoclastic activity and significantly increased gene expression for osteoclast differentiation and activation. Melatonin treatment significantly stimulated Calcitonin (an osteoclast-inhibiting hormone) mRNA expression and decreased the mRNA expression of receptor activator of nuclear factor κB ligand (a promoter of osteoclastogenesis), which coincided with suppressed gene expression levels for osteoclast functions. This is the first study to report the inhibitory effect of melatonin on osteoclastic activation by microgravity. We also observed a novel action pathway of melatonin on osteoclasts via an increase in CALCITONIN secretion. Melatonin could be the source of a potential novel drug to prevent bone loss during space flight.

Development of oral epithelial cell line ROE2 with differentiation potential from transgenic rats harboring temperature-sensitive simian virus40 large T-antigen gene.

We have developed an immortalized oral epithelial cell line, ROE2, from fetal transgenic rats harboring temperature-sensitive simian virus 40 large T-antigen gene. The cells grew continuously at either a permissive temperature of 33°C or an intermediate temperature of 37°C. At the nonpermissive temperature of 39°C, on the other hand, growth decreased significantly, and the Sub-G1 phase of the cell cycle increased, indicating that the cells undergo apoptosis at a nonpermissive temperature. Histological and immunocytochemical analyses revealed that ROE2 cells at 37°C had a stratified epithelial-like morphology and expressed cytokeratins Krt4 and Krt13, marker proteins for oral nonkeratinized epithelial cells. Global-scale comprehensive microarray analysis, coupled with bioinformatics tools, demonstrated a significant gene network that was obtained from the upregulated genes. The gene network contained 16 genes, including Cdkn1a, Fos, Krt13, and Prdm1, and was associated mainly with the biological process of skin development in the category of biological functions, organ development. These four genes were validated by quantitative real-time polymerase chain reaction, and the results were nearly consistent with the microarray data. It is therefore anticipated that this cell line will be useful as an in vitro model for studies such as physiological functions, as well as for gene expression in oral epithelial cells.

Polychlorinated biphenyl (118) activates osteoclasts and induces bone resorption in goldfish.

To analyze the effect of polychlorinated biphenyl (PCB) 118 on fish bone metabolism, we examined osteoclastic and osteoblastic activities, as well as plasma calcium levels, in the scales of PCB (118)-injected goldfish. In addition, effect of PCB (118) on osteoclasts and osteoblasts was investigated in vitro. Immature goldfish, in which the endogenous effects of sex steroids are negligible, were used. PCB (118) was solubilized in dimethyl sulfoxide at a concentration of 10 ppm. At 1 and 2 days after PCB (118) injection (100 ng/g body weight), both osteoclastic and osteoblastic activities, and plasma calcium levels were measured. In an in vitro study, then, both osteoclastic and osteoblastic activities as well as each marker mRNA expression were examined. At 2 days, scale osteoclastic activity in PCB (118)-injected goldfish increased significantly, while osteoblastic activity did not change significantly. Corresponding to osteoclastic activity, plasma calcium levels increased significantly at 2 days after PCB (118) administration. Osteoclastic activation also occurred in the marker enzyme activities and mRNA expressions in vitro. Thus, we conclude that PCB (118) disrupts bone metabolism in goldfish both in vivo and in vitro experiments.

Common gene expression patterns responsive to mild temperature hyperthermia in normal human fibroblastic cells.

PURPOSE: Heat stress induces complex cellular responses, and its detailed molecular mechanisms still remain to be clarified. The objective of this study was to investigate the molecular mechanisms underlying cellular responses to mild hyperthermia (MHT) in normal human fibroblastic (NHF) cells. MATERIALS AND METHODS: Cells were treated with MHT (41°C, 30 min) and then cultured at 37°C. Gene expression was determined by the GeneChip® system and bioinformatics tools. RESULTS: Treatment of the NHF cell lines, Hs68 and OUMS-36, with MHT did not affect the cell viability or cell cycle. In contrast, many probe sets were differentially expressed by >1.5-fold in both cell lines after MHT treatment. Of the 1,196 commonly and differentially expressed probe sets analysed by k-means clustering, three gene clusters, Up-I, Down-I and Down-II, were observed. Interestingly, two gene networks were obtained from the up-regulated genes in cluster Up-I. The gene network E contained DDIT3 and HSPA5 and was mainly associated with the biological process of endoplasmic reticulum stress, while the network S contained HBEGF and LIF and was associated with the biological process of cell survival. Eighteen genes were validated by quantitative real-time polymerase chain reaction, consistent with the microarray data, in four kinds of NHF cells. CONCLUSIONS: Common genes that were differentially expressed and/or acted within a gene network in response to MHT in NHF cells were identified. These findings provide the molecular basis for a further understanding of the mechanisms of the MHT response in NHF cells.

Prostaglandin E2 increases both osteoblastic and osteoclastic activity in the scales and participates in calcium metabolism in goldfish.

Using our original in vitro assay system with goldfish scales, we examined the direct effect of prostaglandin E2 (PGE2) on osteoclasts and osteoblasts in teleosts. In this assay system, we measured the activity of alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) as respective indicators of each activity in osteoblasts and osteoclasts. ALP activity in scales significantly increased following treatment at high concentration of PGE2(10⁻7 and 10⁻6 M) over 6 hrs of incubation. At 18 hrs of incubation, ALP activity also significantly increased in the PGE2 (10⁻9 to 10⁻6 M)-treated scale. In the case of osteoclasts, TRAP activity tended to increase at 6 hrs of incubation, and then significantly increased at 18 hrs of incubation by PGE2 (10(-7) to 10⁻6 M) treatment. At 18 hrs of incubation, the mRNA expression of osteoclastic markers (TRAP and cathepsin K) and receptor activator of the NF-κB ligand (RANKL), an activating factor of osteoclasts expressed in osteoblasts, increased in PGE2 treated-scales. Thus, PGE2 acts on osteoblasts, and then increases the osteoclastic activity in the scales of goldfish as it does in the bone of mammals. In an in vivo experiment, plasma calcium levels and scale TRAP and ALP activities in the PGE2-injencted goldfish increased significantly. We conclude that, in teleosts, PGE2 activates both osteoblasts and osteoclasts and participates in calcium metabolism.

Gene networks related to the cell death elicited by hyperthermia in human oral squamous cell carcinoma HSC-3 cells.

Local hyperthermia (HT) for various types of malignant tumors has shown promising antitumor effects. To confirm the detailed molecular mechanism underlying cell death induced by HT, gene expression patterns and gene networks in human oral squamous cell carcinoma (OSCC) cells were examined using a combination of DNA microarray and bioinformatics tools. OSCC HSC-3 cells were treated with HT at 44˚C for 90 min or mild hyperthermia (MHT) at 42˚C for 90 min, followed by culturing at 37˚C for 0-24 h. Treatment of cells with HT prevented cell proliferation (62%) and induced cell death (17%), whereas these alterations were not observed in cells treated with MHT. Microarray analysis revealed substantial differences with respect to gene expression patterns and biological function for the two different hyperthermic treatments. Moreover, we identified the temperature-specific gene networks D and H that were obtained from significantly up-regulated genes in the HT and MHT conditions, respectively, using Ingenuity pathway analysis tools. Gene network D, which contains 14 genes such as ATF3, DUSP1 and JUN, was associated with relevant biological functions including cell death and cellular movement. Gene network H, which contains 13 genes such as BAG3, DNAJB1 and HSPA1B, was associated with cellular function and maintenance and cellular assembly and organization. These findings provide a basis for understanding the detailed molecular mechanisms of cell death elicited by HT in human OSCC cells.

Identification of biological functions and gene networks regulated by heat stress in U937 human lymphoma cells.

Although cancer cells exposed to temperatures >42.5°C undergo cell death as the temperature rises, exposure of up to 42.5°C induces slight or no cytotoxicity. The temperature of 42.5°C is, therefore, well known to be the inflection point of hyperthermia. To better understand the molecular mechanisms underlying cellular responses to heat stress at temperatures higher and lower than the inflection point, we carried out global scale microarray and computational gene expression analyses. Human leukemia U937 cells were incubated at 42°C or 44°C for 15 min and cultured at 37°C for 0-6 h. Apoptosis accompanied by the activation of caspase-3 and DNA fragmentation was only observed in cells treated with heat stress at 44°C, but not at 42°C. Although a large number of genes were differentially expressed by a factor of 2.0 or greater, we found substantial differences with respect to the biological functions and gene networks of the genes differentially expressed at the two temperatures examined. Interestingly, we identified temperature-specific gene networks that were considered to be mainly associated with cell death or cellular compromise and cellular function and maintenance at 44°C or 42°C, respectively, by using the Ingenuity pathway analysis tools. These findings provide the molecular basis for a further understanding of the mechanisms of the biological changes that are responsive to heat stress in human lymphoma cells.

Osteoblast activity in the goldfish scale responds sensitively to mechanical stress.

The adaptive response of bone to mechanical loading in teleosts is not well understood. We recently developed a new assay system using teleost scales, which consists of osteoblasts, osteoclasts, and bone matrix protein. In this system, alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) were used as markers of osteoblasts and osteoclasts, respectively. Using this assay system, we examined the effects of mechanical loading on ALP and TRAP activity in goldfish scales. ALP activity in the scales was significantly elevated (p<0.01) by ultrasound stimuli (1 MHz, 50% duty factor, 0.5 Hz pulse repetition frequency, 60 mW/cm(2) [I(SATA)] and 6 min) after both 18 h and 24h of incubation while TRAP activity remained unchanged. In addition, mRNA expression of both insulin-like growth factor-I (IGF-I) and estrogen receptors (ER) increased significantly, as did ALP activity. After the goldfish had been swimming for 3 days (speed: 2 body lengths/second, duration: 3h/day), the scales' ALP activity increased significantly (p<0.01) but TRAP activity did not change. These in vitro and in vivo results strongly suggest that osteoblasts in the goldfish scale respond sensitively to mechanical stress and may be important in promoting bone formation.

Ultrasound-induced apoptosis in the presence of Sonazoid and associated alterations in gene expression levels: a possible therapeutic application.

Ultrasound (US) has been shown to induce apoptosis and cell lysis in cancer cells. In this study, we report on the potential of using Sonazoid, a new echo-contrast agent, that is chemically more stable and US-resistant in combination with US in cancer therapy. The biological effects and their mechanisms in the presence or absence of ultrasonic exposure in vitro were investigated. In addition, the impact of the agent on the expression levels of genes responsive to US was studied using global-scale microarrays and computational gene expression analysis tools. Our results show that the combination led to enhanced cell killing in the presence of 1 MHz acoustic field. The apoptosis induction was shown to be mediated by the mitochondrial pathway. The occurrence of US-induced DNA damage was also observed. Despite these findings, the agent at concentrations similar to those clinically used can be considered as well tolerated. Furthermore, Sonazoid enhanced expression of genes that related to apoptosis and are responsive to US, although it alone had almost no effect. These results indicate the potential of Sonazoid for US contrast enhancement as well as the possibility of its use in US-aided therapies.

Multicenter phase 2 study of induction chemotherapy with docetaxel and nedaplatin for oral squamous cell carcinoma.

PURPOSE: To determine the clinical and hisotological efficacy and toxicities of induction chemotherapy with docetaxel (DOC) and nedaplatin (CDGP) for oral squamous cell carcinoma (OSCC) in the preoperative setting. METHODS: A total of 30 patients with locally advanced but operable OSCC were enrolled. Combination induction chemotherapy consisted of DOC 60 mg/m2 followed by CDGP 100 mg/m2. RESULTS: All patients received one cycle of chemotherapy. In the clinical assessment, ten patients achieved partial response for an overall response rate of 33.3% (95% CI, 16.4-50.2%). Histological assessment of surgical specimens showed an overall response rate of 56.6% (95% CI, 38.9-74.3%). Although severe neutropenia was observed in 90% of patients, only one patient (3.3%) experienced severe infection. Toxicities associated with this regimen did not interfere with planned radical surgery. CONCLUSIONS: A single cycle of preoperative combination chemotherapy with DOC and CDGP showed moderate histological activity with an acceptable safety profile for the planned radical surgery. Further studies testing more cycles before surgery might be more appropriate.

Gene networks involved in apoptosis induced by hyperthermia in human lymphoma U937 cells.

To define the molecular mechanisms that mediate hyperthermia-induced apoptosis, we performed microarray and computational gene expression analyses. U937 cells, a human myelomonocytic lymphoma cell line, were treated with hyperthermia at 42 degrees C for 90 min and cultured at 37 degrees C. Apoptotic cells ( approximately 15%) were seen 6 h after hyperthermic treatment, and elevated expression of heat shock proteins (HSPs) including Hsp27, Hsp40, and Hsp70 was detected, following the activation of heat shock factor-1. Of the 54,675 probe sets analyzed, 1334 were upregulated and 4214 were downregulated by >2.0-fold in the cells treated with hyperthermia. A non-hierarchical gene clustering algorithm, K-means clustering, demonstrated 10 gene clusters. The gene network U1 or U2 that was obtained from up-regulated genes in cluster I or IX contained HSPA1B, DNAJB1, HSPH1, and TXN or PML, LYN, and DUSP1, and were mainly associated with cellular compromise, and cellular function and maintenance or death, and cancer, respectively. In the decreased gene cluster II, the gene network D1 including CCNE1 and CEBPE was associated with the cell cycle and cellular growth and proliferation. These findings will provide a basis for understanding the detailed molecular mechanisms of apoptosis induced by hyperthermia at 42 degrees C in cells.

Monohydroxylated polycyclic aromatic hydrocarbons inhibit both osteoclastic and osteoblastic activities in teleost scales.

AIMS: We previously demonstrated that monohydroxylated polycyclic aromatic hydrocarbons (OHPAHs) bound to a human estrogen receptor (ER) by a yeast two-hybrid assay, but polycyclic aromatic hydrocarbons did not have a binding activity. Therefore, the direct effect of 3-hydroxybenz[a]anthracene (3-OHBaA) and 4-hydroxybenz[a]anthracene (4-OHBaA) on osteoclasts and osteoblasts in teleosts was examined. As a negative control, 1-hydroxypyrene (1-OHPy), which has no binding activity to human ER, was used. MAIN METHODS: The effect of OHPAHs on osteoclasts and osteoblasts was examined by an assay system using teleost scale as each marker: tartrate-resistant acid phosphatase for osteoclasts and alkaline phosphatase for osteoblasts. Changes in cathepsin K (an osteoclastic marker) and insulin-like growth factor-I (IGF-I) (an osteoblastic marker) mRNA expressions in 4-OHBaA-treated goldfish scales were examined by using a reverse transcription-polymerase chain reaction. KEY FINDINGS: In both goldfish (a freshwater teleost) and wrasse (a marine teleost), the osteoclastic activity in the scales was significantly suppressed by 3-OHBaA and 4-OHBaA, although 1-OHPy did not affect the osteoclastic activity. In reference to osteoblasts, the osteoblastic activity decreased with both 3-OHBaA and 4-OHBaA and did not change with the 1-OHPy treatment. However, 17beta-estradiol (E(2)) significantly increased both the osteoclastic and osteoblastic activities in the scales of both goldfish and wrasse. The mRNA expressions of both cathepsin K and IGF-I decreased in the 4-OHBaA-treated scales but increased in the E(2)-treated scales. SIGNIFICANCE: The current data are the first to demonstrate that 3-OHBaA and 4-OHBaA inhibited both osteoclasts and osteoblasts and disrupted the bone metabolism in teleosts.

Genes and genetic networks responsive to mild hyperthermia in human lymphoma U937 cells.

In this study, to better understand the molecular mechanism underlying cellular responses to mild hyperthermia, we investigated gene expression patterns and genetic networks in human myelomonocytic lymphoma U937 cells using high-density oligonucleotide microarrays and computational gene expression analysis tools. The cells were incubated at 41 degrees C for 30 min (mild hyperthermia treatment) and then at 37 degrees C for 0-6 h. Although the mild hyperthermia treatment of the cells did not induce apoptosis, significant increases in the protein expression levels of heat shock proteins (HSPs), namely, Hsp27, Hsp40 and Hsp70, were observed following the activation of heat shock factor-1. Of the 22,283 probe sets analyzed, 423 probe sets were up-regulated and 515 probe sets were down-regulated by >1.5-fold in the cells 3 h post-treatment. Computational gene network analysis demonstrated that the significant genetic network A that contained many HSPs such as DNAJB1, HSPA1A, and HSPA1B was associated with cellular function and maintenance, post-transcriptional modification, or protein folding. Moreover, the significant genetic network B whose core contained v-myc myelocytomatosis viral oncogene homolog (MYC) was associated with cell morphology, cell cycle, and cellular development. The expression levels of nine selected genes were comparable to those determined by microarray analysis with real-time quantitative PCR assay. The present results indicate that mild hyperthermia affects the expression of a large number of genes and provides additional novel insights into the molecular basis of mild hyperthermia in cells.

Genetic networks responsive to low-intensity pulsed ultrasound in human lymphoma U937 cells.

To clarify the detailed molecular mechanism underlying cellular responses to nonthermal low-intensity pulsed ultrasound (LIPUS), gene expression patterns and genetic networks in human lymphoma U937 cells were examined using global-scale microarrays and computational gene expression analysis tools. Six hours after LIPUS treatment (0.3W/cm(2) for 1min), apoptosis (14+/-3.8%, mean+/-SD) without no cell lysis was observed. Of 22,283 probe sets analyzed, LIPUS down-regulated 193 genes and up-regulated 201 genes by >1.5-fold. For down-regulated genes, the significant genetic network D was associated with cellular growth and proliferation, gene expression, or cellular development. For up-regulated genes, the significant genetic network U was associated with cellular movement, cell morphology, and cell death. The present results indicate that LIPUS affects the expression of many genes and will provide novel insight into the biomolecular mechanisms of LIPUS in therapeutic application for cancer therapy.

Gene expression in enhanced apoptosis of human lymphoma U937 cells treated with the combination of different free radical generators and hyperthermia.

The effects of various free radicals derived from 6-formylpterin (6-FP), alpha-phenyl-tert-butyl nitrone (PBN) and 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) combined with hyperthermia, on gene expression in similarly enhanced apoptosis of human lymphoma U937 cells were investigated using cDNA microarrays containing approximately 16,600 genes and computational gene expression analysis tools. When the cells were treated for 10 min at 44 degrees C (15% apoptosis level), 39 up-regulated and 3 down-regulated genes were identified. In the up-regulated genes, apoptosis- and unfolded protein response-associated genes were contained. The combined treatment with heat and either chemical enhanced apoptosis level (approximately 30%) and showed a chemical-specific gene expression pattern. Furthermore, the expression levels of selected genes were confirmed by a real-time quantitative PCR. The present results will provide a basis for further understanding the molecular mechanisms in enhancement of heat-induced apoptosis by different intracellular oxidative stress.

Tributyltin inhibits osteoblastic activity and disrupts calcium metabolism through an increase in plasma calcium and calcitonin levels in teleosts.

To examine the direct effects of tributyltin acetate (TBTA) on osteoclasts and osteoblasts, teleost scale, which has both osteoclasts and osteoblasts and is similar to mammalian membrane bone, was used in the present study. The activities of tartrate-resistant acid phosphatase and alkaline-phosphatase, as respective indicators of activity in both cells, were used. In freshwater teleost (goldfish) and marine teleosts (nibbler and wrasse), the osteoclastic activity in the scales did not change as a result of TBTA treatment (10(-9) to 10(-5) M). However, the osteoblastic activity decreased in the goldfish, nibbler, and wrasse after 6 h of incubation. In goldfish, even 10(-10) M of TBTA significantly inhibited the osteoblastic activity. The inhibitory activity in goldfish was stronger than that in nibbler and wrasse. Therefore, details of the mechanism were examined using goldfish. The mRNA expressions of the estrogen receptor and insulin-like growth factor-I, which participate in osteoblastic growth and differentiation, decreased in the TBTA-treated scales. However, the mRNA expression of metallothionein (MT), a metal-binding protein that protects the organism from heavy metal, increased much less than those of cadmium and methyl-mercury. Furthermore, we showed that the plasma calcium and hypocalcemic hormone (calcitonin) level increased in goldfish kept in water containing TBTA (10(-10) and 10(-8) M). The current data are the first to demonstrate that, in teleosts, TBTA inhibits osteoblastic activity without affecting osteoclastic activity and disrupts the calcium metabolism, including the calcemic hormone, in goldfish.

A new retractor for surgical removal of mandibular torus.

INTRODUCTION: A newly devised retractor for mandibular torus is presented. It has a half-spoon-shaped head and was applied to various cases of mandibular torus for its evaluation. RESULTS: It was found that the elevated mucoperiosteum flap was safely protected lingually by using this retractor. Various mandibular tori were completely resected without damaging the surrounding tissues.

Multicenter phase I trial of induction chemotherapy with docetaxel and nedaplatin for oral squamous cell carcinoma.

A phase I study of combination neoadjuvant chemotherapy with docetaxel (DOC) and nadaplatin (CDGP) was conducted in patients with untreated, advanced but operable oral squamous cell carcinoma. DOC was administered (one-hour i.v. infusion) on day 1 followed by CDGP (one-hour i.v. infusion). The dose levels of DOC and CDGP tested were 60/70, 60/80, 60/90, 60/100, and 70/100 (mg/m(2)). Fifteen patients enrolled in this study and median age was 60 years. Dose-limiting toxicity (DLT) occurred in one of six patients at DOC dose of 60 mg/m(2) and CDGP dose of 100 mg/m(2). The DLT was diarrhea. Because one additional patient at this dose-level developed grade 4 neutropenia lasting for 4 days that approached DLT and because fear of severe hematological problems was predicted, further dose escalation was not performed. This combination chemotherapy is active and well tolerated and warrants a phase II study. We recommended 60 mg/m(2) DOC and 100 mg/m(2) CDGP for phase II study.

Enhancement of radiation-induced apoptosis by 6-formylpterin.

Radiation-induced apoptosis and its possible enhancement in the presence of 6-formylpterin (6-FP), a metabolite of folic acid, were examined in human myelomonocytic lymphoma U937 cells. When cells were treated with 6-FP at a nontoxic concentration of 300 microM, and then exposed to X-rays at a dose of 10 Gy, significant enhancement of radiation-induced apoptosis as determined by nuclear morphological change, phosphatidylserine (PS) externalization and DNA fragmentation were observed. Flow cytometry for the detection of intracellular hydrogen peroxide (H2O2) revealed that 6-FP increased the formation of intracellular H2O2, which further increased when the cells were irradiated. Decrease of mitochondria trans-membrane potential (MMP), release of cytochrome c from mitochondria, and activation of caspase-3 were enhanced after the combined treatment. Remarkable activation of protein kinase C delta (PKC delta) and its translocation from cytosol to mitochondria were detected in combined treatment. Increase of intracellular Ca2+ concentrations ([Ca2+]i) was also observed, however, neither calpain I nor calpain II could inhibit the apoptosis. In addition, c-Jun NH2-terminal kinase (JNK) activation was not enhanced in the combined treatment. A protein involved in a caspase-independent apoptosis pathway, apoptosis inducing factor (AIF), remained unchanged even 3 h after treatment. These results indicate that intracellular H2O2 generated by 6-FP enhances radiation-induced apoptosis via the mitochondria-mediated caspase-dependent pathway, with the active involvement of PKC delta.

Prognostic significance of p34cdc2 expression in tongue squamous cell carcinoma.

We evaluated the prognostic significance of p34cdc2 expression in 50 tongue squamous cell carcinomas (SCC) using immunohistochemical methods. The p34cdc2 protein was expressed in 33 cases of 50 tumor tissues (66.0%), compared with 15 cases of 42 controlled epithelia (35.7%). The expression of p34cdc2 was significantly correlated with the histological grade of tongue carcinoma (P<0.01). In addition, on evaluation of prognosis of tumor, the p34cdc2 protein was overexpressed in recurrent tumors or in those with lymph node metastasis. Statistics showed a significant reduction in the 5-year accumulative survival rate of p34cdc2 positive cases compared with p34cdc2 negative cases (P<0.01). Namely, the p34cdc2 positive patients had worse prognosis. The results suggested that the expression of p34cdc2 suited to the histological grade might reflect the malignant degree of tongue carcinoma biologically. Therefore, the evaluation of p34cdc2 expression was of benefit in elucidating the nature of tumor malignancy and the prognostic prediction of tongue SCC.