Migration induced by epidermal and hepatocyte growth factors in oral squamous carcinoma cells in vitro: role of MEK/ERK, p38 and PI-3 kinase/Akt

J Oral Pathol Med (2012) 41 : 547–558 Background: Cell migration is a necessary part of malignant invasiveness. Oral squamous cell carcinomas (OSCC) have a great tendency for local invasive growth. We have investigated signalling pathways involved in cell migration induced by epidermal growth factor (EGF) and hepatocyte growth factor (HGF) in OSCC cells and examined the effects of various experimental and clinically approved anti‐tumour signal inhibitors on the migratory activity. Methods: Migration was studied in three human OSCC cell lines, using a scratch wound assay in vitro and time‐lapse cinematography. Specific phosphorylation of signalling proteins was assessed by Western blotting. Results: In the E10 cell line, EGF and HGF induced phosphorylation of EGF receptor (EGFR) and Met, respectively, phosphorylation of ERK1/2, p38 and Akt, and dose‐dependent activation of cell migration. Addition of the EGFR‐specific inhibitors cetuximab (antibody) or gefitinib (tyrosine kinase blocker) abolished cell migration elicited by EGF. Similarly, a Met kinase inhibitor (SU11274) blocked HGF‐induced cell migration. Furthermore, when three cell lines were treated with blockers of the MEK/ERK, p38 or the PI‐3 kinase/Akt pathways, the migratory response to both EGF and HGF was inhibited, but to varying degrees. Notably, in E10 and D12 cells, HGF‐induced migration was particularly sensitive to PI‐3 K‐inhibition, while in C12 cells, both HGF‐ and EGF‐induced migration were highly sensitive to p38‐blockade. Conclusion: The results demonstrate that the MEK/ERK, p38 and PI‐3 kinase pathways are all involved in mediating the increased migration in OSCC cell lines induced by EGF and HGF, but their relative importance and the effects of specific signal inhibitors differ.     

Cetuximab inhibits oral squamous cell carcinoma invasion and metastasis via degradation of epidermal growth factor receptor

Cetuximab (Erbitux, C225) is a chimeric monoclonal antibody that binds to the extracellular domain of epidermal growth factor receptor (EGFR), inhibiting tumor growth, invasion, angiogenesis and metastasis. However, the mechanisms underlying the effect of Cetuximab in human oral squamous cell carcinoma (OSCC) remain unclear. Here, we report that Cetuximab modulates EGFR protein stability through the ubiquitin/proteasome pathway, resulting in the inhibition of human OSCC growth. Cetuximab significantly inhibited the migration and invasion of human OSCC cells by blocking epithelial/mesenchymal transition (EMT) and the AKT and ERK pathways. Furthermore, Cetuximab‐inhibited cell growth by modulating the expression of integrin β5. Taken together, these results provide novel insights into the mechanism of Cetuximab action and suggest potential therapeutic strategies for OSCC.     

Endothelial cell Bcl-2 and lymph node metastasis in patients with oral squamous cell carcinoma

J Oral Pathol Med (2012) 41 : 124–130 Background: Loco‐regional spread of disease causes high morbidity and is associated with the poor prognosis of malignant oral tumors. Better understanding of mechanisms underlying the establishment of lymph node metastasis is necessary for the development of more effective therapies for patients with oral cancer. The aims of this work were to evaluate a possible correlation between endothelial cell Bcl‐2 and lymph node metastasis in patients with oral squamous cell carcinoma (OSCC), and to study signaling pathways that regulate Bcl‐2 expression in lymphatic endothelial cells. Methods: Endothelial cells were selectively retrieved from paraffin‐embedded tissue sections of primary human OSCC from patients with or without lymph node metastasis by laser capture microdissection. RT‐PCR was used to evaluate Bcl‐2 expression in tumor‐associated endothelial cells and in tumor cells. In vitro, mechanistic studies were performed to examine the effect of vascular endothelial growth factor (VEGF)‐C on the expression of Bcl‐2 in primary human lymphatic endothelial cells. Results:  We observed that Bcl‐2 expression is upregulated in the endothelial cells of human oral tumors with lymph node metastasis as compared to endothelial cells from stage‐matched tumors without metastasis. VEGF‐C induced Bcl‐2 expression in lymphatic endothelial cells via VEGFR‐3 and PI3k/Akt signaling. Notably, OSCC cells express VEGF‐C and induce Bcl‐2 in lymphatic endothelial cells. Conclusions: Collectively, this work unveiled a mechanism for the induction of Bcl‐2 in lymphatic endothelial cells and suggested that endothelial cell Bcl‐2 contributes to lymph node metastasis in patients with oral squamous cell carcinoma.     

Physiologic levels of epidermal growth factor in saliva stimulate cell migration of an oral epithelial cell line,HO-1-N-1

An oral epithelial cell line derived from buccal mucosa squamous cell carcinoma, HO-1-N-1, was used to elucidate the role of epidermal growth factor (EGF) in saliva on wound healing of the oral mucosa. The effects of EGF on DNA synthesis, and cell migration was studied and the related signal transduction pathways examined. DNA synthesis by HO-1-N-1 cells was stimulated dose-dependently by 1-10 ng ml(-1) EGF, but significantly inhibited by addition of a PI3-K inhibitor (wortmannin), a p38 MAPK inhibitor (SB203580) or an MEKs inhibitor (PD98059). Cell migration was also accelerated by addition of 1-10 ng ml(-1) EGF; however, the migration rate was decreased to 30% by adding PD98059, to 40% by adding a tyrosine kinase inhibitor (herbimycin A), and to 60% by adding wortmannin or dexamethasone. These results indicate that the physiologic concentration of EGF in saliva may stimulate proliferation and migration of oral epithelial cells for wound healing, when the oral mucosa has been injured. Furthermore, this study revealed that EGF-stimulated signal transduction pathways for epithelial cell proliferation and cell migration are different.     

核因子κB/B细胞淋巴瘤2信号通路与糖原合成激酶3β在口腔鳞状细胞癌中的表达及临床意义

目的 初步探讨核因子κB（NF-κB）/B细胞淋巴瘤2（Bcl-2）信号通路与糖原合成激酶3β（GSK-3β）在口腔鳞状细胞癌（OSCC）组织中的表达情况,为OSCC的早期诊断及治疗提供参考。方法 收集OSCC标本55例及癌旁组织10例,采用免疫组织化学SP法检测OSCC组织及癌旁组织中GSK-3β、NF-κB及Bcl-2的表达情况,并分析三者相互之间的表达关系及三者与患者临床病理参数之间的关系。结果 GSK-3β、NF-κB及Bcl-2在OSCC中的表达高于癌旁组织中的表达（P<0.01）,且三者与患者年龄、性别以及临床分期无明显关系（P>0.05）。Bcl-2在不同组织学分化程度的OSCC组织中的表达有统计学差异（P<0.05）,而GSK-3β及NF-κB在不同组织学分化程度的OSCC中的表达无统计学差异（P>0.05）。GSK-3β、NF-κB及Bcl-2在OSCC中的表达均两两相关（P<0.05）。结论 GSK-3β、NF-κB及Bcl-2在OSCC组织中的表达显著高于癌旁组织中的表达,检测GSK-3β、NF-κB及Bcl-2的表达水平对于OSCC的早期诊断和预后估计有一定的临床意义。     

COX-2、bFGF在口腔鳞癌发生发展过程中的表达及相互关系

目的:研究环氧合酶-2(cyclooxygenase-2,COX-2)、碱性成纤维细胞生长因子(basic fibroblast growth factors,bFGF)在口腔鳞状细胞癌(oral squamous cell carcinoma,OSCC)的发生、发展过程中的表达情况,进而探求COX-2、bFGF在OSCC发生发展过程中的作用及相互关系。方法:应用COX-2,bFGF多克隆抗体对25例口腔白斑(癌前病变)(oral leukoplakia,OLK)、23例口腔鳞状细胞癌进行检测,另取10例口腔正常颊、舌黏膜组织为对照组,做组织切片进行免疫组化研究。结果:COX-2在正常口腔黏膜不表达,bFGF在正常口腔黏膜仅为弱表达或不表达,COX-2、bFGF在口腔白斑中有一定的表达,染色强度与正常口腔黏膜相比具有显著性差异(P<0.01 ),COX-2、bFGF在口腔鳞癌中高表达,其染色强度强于口腔白斑(P<0.01),口腔鳞癌中COX-2的表达阳性率为82.61%,bFGF的表达阳性率为86.96%,二者共同表达阳性率为78.26%,r=0.8,P<0.05,二者表达呈正相关关系。结论:COX-2、bFGF在口腔鳞癌发生、发展中起着重要作用,二者表达显著相关,在口腔鳞癌的发生发展中有协同作用,COX-2可促进bFGF的形成。     

口腔鳞癌中COX-2、VEGF-C的表达及其临床意义

目的：检测口腔鳞癌（OSCC）中COX-2、VEGF-C的表达,以探讨COX-2、VEGF-C与OSCC淋巴转移的关系及其临床意义。方法：应用免疫组织化学染色S-P法检测COX-2、VEGF-C在OSCC中的表达情况。结果：COX-2在OSCC组织中表达明显高于正常口腔黏膜（P〈0.01）;COX-2在伴淋巴结转移者的阳性表达率明显高于不伴淋巴结转移者（P〈0.05）。VEGF-C在OSCC组织中表达明显高于正常口腔黏膜（P〈0.01）;VEGF-C在伴淋巴结转移者的阳性表达率明显高于不伴淋巴结转移者（P〈0.05）。40例OSCC组织中,COX-2与VEGF-C表达共阳性16例（40.0%）,表达阴性10例（25.0%）,二者在OSCC中的表达成正相关（r=0.517,P〈0.01）。结论：COX-2、VEGF-C在OSCC组织中表达明显上调,并与淋巴结转移有关,提示二者有可能在OSCC的生长及转移中起重要作用。COX-2表达上调与VEGF-C表达成正相关,提示二者在OSCC的淋巴管生成及侵袭转移中可能起协同作用。     

口腔鳞癌中COX-2的表达与淋巴管生成的关系

目的:检测口腔鳞癌中环氧合酶-2(COX-2)和微淋巴管密度(MLVD)的表达,探讨COX-2与口腔鳞癌淋巴管生成的关系及临床意义.方法:应用免疫组织化学染色(S-P法)检测40例口腔鳞癌组织、14例正常口腔黏膜组织中COX-2的表达情况.应用免疫双重组织化学染色检测肿瘤中的MLVD.结果:COX-2 在口腔鳞癌中的阳性表达率为70.0 %,明显高于对照组(P ＜ 0.01).COX-2的表达与口腔鳞癌颈淋巴结转移、TNM分期相关(P ＜0.05).COX-2表达阳性组的MLVD值为23.3±1.9,显著高于阴性组的MLVD值16.9±2.2( t ＝ 9.295,P ＜ 0.01).结论:COX-2在口腔鳞癌组织中表达明显上调,并与淋巴管生成、颈淋巴结转移及TNM分期等临床病理生物学行为有关,COX-2可能在口腔鳞癌的生长及转移中起重要作用.     

转化生长因子β1对口腔鳞状细胞癌脑转移细胞系Tb细胞生长抑制作用的研究

目的 探讨转化生长因子(transforming growth factor,TGF)β1对口腔鳞状细胞癌脑转移细胞系Tb细胞的生长抑制作用及可能的机制.方法 采用细胞计数法检测TGF-β1对Tb细胞的生长抑制作用,流式细胞仪检测细胞周期的变化,微阵列分析法(superarray)筛查smad蛋白介导的TGF-B(TGF-β-Smads)信号通路中基因表达水平的变化,反转录聚合酶链反应(RT-PCR)验证差异表达基因.结果 TGF-β1对Tb细胞有明显的生长抑制作用(P<0.05).流式细胞仪检测显示,TGF-β1能够使Tb细胞周期阻滞于G1期(P<0.05).微阵列分析法筛查结果显示,TGF-β1作用后,活化素受体样激酶1(activin receptor-like kinase-1,ACVRL-1)、抗苗勒激素(anti-mullerian hirmine,AMH)、细胞周期蛋白依赖性激酶抑制因子2B(cyclim-dependent kinase inhibitor-2B,CDKN-2B)、TGF-相互作用因子(indnced factor,TGIF)基因表达增加,而畸形肿瘤衍生生长因子1(teratocarcinomaderived growth factor-1,TDGF-1)基因表达降低.RT-PCR验证结果表明,ACVR-1(0.67±0.08)、CDKN-2B基因表达(2.16±0.95)与微阵列分析法结果一致,差异有统计学意义(P<0.05),AMH(0.38±0.07)、TDGF-1(0.44±0.06)及TGIF(0.52±0.10)基因表达水平无统计学意义(P>0.05).结论 TGF±β1对口腔鳞状细胞癌脑转移细胞系Tb细胞有明显的生长抑制作用,其机制可能与细胞周期调控及调节TGF-β1-Smads信号通路中ACVRL-1、CDKN-2B基因表达有关.     

Elevated expression of cyclooxygenase (COX)-2 in oral squamous cell carcinoma – evidence for COX-2 induction by areca quid ingredients in oral keratinocytes

BACKGROUND: Elevated expression of cyclooxygenase (COX)-2 has been demonstrated in several human cancers. Whether COX-2 is up-regulated in areca quid (AQ) related oral squamous cell carcinoma (OSCC) is unknown and the potential of AQ ingredients to induce COX-2 expression has not been studied. METHODS: COX-2 expression was analyzed by immunohistochemistry and RT-PCR in oral tissues. The COX-2 mRNA and protein induction potential of AQ ingredients were analyzed by real-time RT-PCR and Western blotting in normal human oral keratinocyte (NHOK). RESULTS: COX-2 protein expression was significantly higher (P < 0.01) in OSCC (n = 27) as compared to their adjacent non-cancerous matched tissue (NCMT). COX-2 protein was nearly undetectable in control normal oral mucosa. The level of COX-2 mRNA was markedly elevated in 63% (12/19) of OSCC compared to NCMT. Hydroxychavicol induced COX-2 mRNA and protein expression in NHOK. CONCLUSIONS: COX-2 protein as well as mRNA expression were significantly enhanced in OSCC as compared to NCMT. Hydroxychavicol, a unique ingredient in AQ, induced COX-2 expression in NHOK, which highlighted early involvement of COX-2 in AQ-associated oral oncogenesis.     

脾络氨酸激酶-核因子κB调控口腔癌相关巨噬细胞中癌痛相关环氧化酶2的机制研究

目的通过体外原代巨噬细胞诱导以及分子生物学的方法,探究口腔癌相关巨噬细胞环氧化酶2（COX-2）上调的机制。方法 构建小鼠原代巨噬细胞,使用Cal27条件培养基（CM）刺激诱导形成口腔癌相关巨噬细胞,使用免疫荧光检测原代巨噬细胞的纯度。使用小分子抑制剂分别抑制脾络氨酸激酶（Syk）及核因子κB（NFκB）通路。使用实时定量聚合酶链反应（PCR）、Western blot检测COX-2及信号通路相关蛋白的变化。结果 所诱导的原代巨噬细胞均特异性表达CD68蛋白。Cal27 CM刺激能够显著提高COX-2的表达（P<0.001）;抑制Syk的磷酸化即能够进一步抑制NFκB-P65的磷酸化,从而导致COX-2的表达显著降低（P<0.01）;而抑制NFκB-P65的磷酸化不能抑制Syk的磷酸化但可以显著降低COX-2的表达（P<0.01）。结论 Syk-NFκB信号通路导致COX-2在口腔癌相关的巨噬细胞中高表达,靶定该信号通路可能是控制口腔癌相关癌痛的新方向。     

MMP-9、COX-2、NF-κB在口腔鳞状细胞癌组织中的表达及意义

目的:探讨基质金属蛋白酶-9(MMP-9)、环氧化物酶-2(COX-2)、细胞核因子KB(NF-κB)在口腔鳞状细胞癌(OSCC)组织中的表达及意义.方法:分别采用实时荧光定量聚合酶链反应(qRT-PCR)、蛋白免疫印迹法(West-ern blot)、免疫组化法检测80例OSCC组织中的表达水平;采用Pearson法...     

Differential induction of heme oxygenase-1 against nicotine-induced cytotoxicity via the PI3K, MAPK, and NF-kappa B pathways in immortalized and malignant human oral keratinocytes

BACKGROUND:  Heme oxygenase-1 (HO-1) exhibits cytoprotective effects in many different cell types and is induced by nicotine exposure in human gingival fibroblasts. However, the role of HO-1 in cancer cells exposed to nicotine has not previously been described.
METHODS:  We investigated the effects of nicotine on HO-1 protein expression and cell viability in immortalized (IHOK) and malignant (HN12) human oral keratinocyte cells using the 3,4,5-dimethylthiazol-2-yl-2,5-diphenyl tetrazolium bromide assay and Western blotting. We also examined the involvement of the phosphoinositide-3-kinase (PI3K), mitogen-activated protein kinase (MAPK), and nuclear factor-κB (NF-κB) signaling pathways in nicotine-induced cytotoxicity and HO-1 levels in IHOK and HN12 cells.
RESULTS:  Nicotine-induced HO-1 production and had cytotoxic effects on cells in both a concentration- and time-dependent manner. Nicotine-induced cytotoxicity and accumulation of HO-1 were greater in IHOK cells than in HN12 cells. Molecular inhibitors of the ERK, p38 MAP kinase, PI3 K, and NF-κB signaling pathways blocked the cytotoxic effects and induction of HO-1 expression by nicotine. Treatment with antioxidants (bilirubin, N -acetylcysteine) protected cells against nicotine-induced cytotoxicity and blocked the upregulation of HO-1, the effects of which were more pronounced in IHOK cells than in HN12 cells.
CONCLUSIONS:  Collectively, these results suggest that HO-1 plays a principal role in the protective response to nicotine in oral cancer and immortalized keratinocytes. Moreover, the addition of exogenous antioxidants may help to protect oral epithelial cells as chemopreventive agents against nicotine-induced oxidative stress.     

SOX2通过PI3K/AKT通路调控口腔鳞癌细胞迁徙的机制研究

目的:研究过表达SOX2通过PI3K/AKT通路促进口腔鳞癌(oral squamous cell carcinoma,OSCC)细胞迁移及上皮间质转化(epithelial mesenchymal transition,EMT)的作用及机制.方法:收集OSCC组织及正常口腔黏膜组织,培养OSCC细胞株Tca83、SC...     

VEGF、EGFR、p16在唇癌与口腔鳞癌中的表达及临床意义

目的 检测血管内皮生长因子（vascular endothelial factor,VEGF)、表皮生长因子受体（epidermal growth for receptor,ERFR)及p16在唇癌及口腔鳞癌组织中的表达分布特征，探讨其在癌发生发展中的作用及临床病理意义，为唇癌及口腔鳞癌的抗血管生成治疗提供临床病理学依据。方法 应用免疫组化LSAB法检测69例唇癌及口腔鳞癌组织中VEGF、EGFR，p16蛋白的表达及变化。结果 唇癌及口腔鳞癌VEGF、EGFR,p16蛋白表达率分别为71．01％、46．37％及28．98％。不同部位唇癌及口腔鳞癌组织间VEGF、GEFR、p16阳性表达率差异无显著性（P＞0．05）；VEGF在唇癌及口腔鳞癌与非瘤组织中的阳性表达率分别为71．01％、10．00％，二者差异有显著性（P＜0．05）；VEGF、EGFR、p16在唇癌及口腔癌组织中的阳性表达无明显相关（P＞0．05）。结论 唇癌及口腔鳞癌组织中VEGF、EGFRp16之间蛋白表达无相关；VEGF在非瘤组织与唇癌及口腔鳞癌中的表达率差异有显著性；VEGF在唇癌及口腔鳞癌发生发展中起重要作用，可作为有用的标志物。     

口腔鳞癌COX-2表达和肿瘤血管生成的研究

目的 探讨环氧化酶-2(COX-2)表达和口腔鳞癌血管生成的关系.方法 免疫组化检测口腔鳞癌COX-2、诱导型一氧化氮合酶(iNOS)、血管内皮生长因子(VEGF)表达,并测定肿瘤微血管密度(MVD).结果 口腔鳞癌COX-2表达与VEGF、iNOS表达密切相关(P＜0.05).口腔鳞癌COX-2表达阳性组和阴性组MVD有显著差异(P＜0.01)结论 口腔鳞癌COX-2表达和肿瘤血管生成有关,iNOS 和VEGF可能参与COX-2对肿瘤血管生成的促进作用.     

COX-2、VEGF在口腔扁平苔藓、口腔白斑及口腔鳞状细胞癌中的表达

目的研究环氧合酶(COX)-2、血管内皮生长因子(VEGF)在口腔扁平苔藓(OLP)、口腔白斑(OLK)及口腔鳞状细胞癌(OSCC)组织中的表达及分布,探讨其在OLP、OLK癌变机制中的作用。方法采用免疫组化法检测33例OLP患者(单纯扁平苔藓19例,伴异常增生14例)、35例OLK患者(单纯增生14例、伴异常增生21例)、31例OSCC患者及10例正常对照者口腔黏膜组织(NOM)中COX-2、VEGF的分布和表达。应用统计分析软件SPSS 13.0对结果进行统计分析。结果COX-2、VEGF在正常口腔黏膜组织无表达或低表达;在单纯扁平苔藓组均为26.32%过表达;在扁平苔藓异常增生组分别为71.43%、64.29%过表达;在白斑单纯增生组过表达情况均为21.42%;在白斑异常增生组分别为80.95%、71.43%过表达;在口腔鳞状细胞癌组分别为93.55%、90.32%过表达;COX-2、VEGF在扁平苔藓异常增生组的表达明显高于单纯扁平苔藓组(P<0.05),低于OSCC组(P<0.05),与白斑异常增生组无明显差异(P>0.05)。COX-2的表达与VEGF表达呈明显正相关(r=0.595,P<0.01)。结论COX-2、VEGF在NOM、OLP及OLK伴异常增生、OSCC的表达逐渐增高,表明COX-2及VEGF与OLP、OLK的异常增生及癌变有关。     

PI3K与PTEN蛋白在口腔鳞癌中的表达及相关性研究

目的：探讨口腔鳞癌中PTEN、PI3K的表达情况,并对其表达水平与临床特征之间的关系进行相关性分析,探讨其与口腔鳞癌发生、发展和转移的关系。方法采用免疫组化SP法对52例口腔鳞癌石蜡标本及20例癌旁正常组织中PTEN、PI3K蛋白的表达情况进行研究,分析其与临床病理特征的关系。结果 PTEN在口腔鳞癌中表达明显低于癌旁正常组织。PI3K表达明显高于癌旁正常组织。PTEN与PI3K表达与细胞分化、临床分期、淋巴结转移相关。PTEN与PI3K阳性表达之间呈负相关。结论 PI3K在口腔鳞癌中的表达上调, PTEN在口腔鳞癌中的表达下调。PTEN与PI3K蛋白表达呈负相关。     

Expression of hepatocyte growth factor and c-met protein is significantly associated with the progression of oral squamous cell carcinoma in Taiwan

BACKGROUND: Hepatocyte growth factor (HGF) is a pleotropic growth factor that regulates cell proliferation, migration, survival, tumor angiogenesis, and tumor cell invasion and metastasis. Its diverse biological effects are mediated through its interaction with its receptor, c-met protein. METHODS: In this study, we examined the expression of HGF and c-met protein in 93 specimens of oral squamous cell carcinoma (OSCC), 10 specimens of oral epithelial dysplasia (OED), 14 specimens of oral epithelial hyperkeratosis (OEH), and 16 specimens of normal oral mucosa (NOM) by immunohistochemistry. The HGF and c-met labeling indices (LIs) in OSCC, OED, OEH, and NOM groups were calculated and compared between groups. The correlation between the expression of HGF or c-met in OSCCs and clinicopathological parameters, or survival of OSCC patients was analyzed statistically to investigate the possible influence of HGF or c-met on the progression and prognosis of OSCCs in Taiwan. RESULTS: Positive HGF or c-met staining was mainly cytoplasmic. The mean HGF LI increased significantly from NOM (3.1 +/- 5.1%) through OEH (32.5 +/- 19.8%) and OED (52.0 +/- 19.3%) to OSCC (71.9 +/- 28.6%; P = 0.000). The mean c-met LI also increased significantly from NOM (25.8 +/- 30.8%) and OEH (34.4 +/- 19.3%) through OED (53.0 +/- 20.0%) to OSCC (73.0 +/- 29.4%; P = 0.000). Statistical analysis showed that the c-met LI in either the tumor center or invasion front was significantly associated with T status, N status, and clinical staging of OSCC. However, only the HGF LI in the tumor invasion front was significantly correlated with N status and clinical staging of OSCC. CONCLUSION: Our results suggest that the expression of HGF and c-met protein is an early event in oral carcinogenesis in Taiwan. The HGF LI in the tumor invasion front and the c-met LI in either the tumor center or invasion front can predict the progression of OSCCs in Taiwan.