Increased expression of Cathepsin B in oral squamous cell carcinoma

Previously, an in vitro cellular carcinogenesis model of oral squamous cell carcinoma (OSCC) was established with a line of human immortalized oral epithelial cells (HIOECs), a line of cancerous HB96 cells and another type of cell (HB56 cells) at the early stage of carcinogenesis. In this study, comparative proteomic analysis identified a panel of differentially expressed proteins among these cells. Cathepsin B was one of the significantly up-regulated proteins accompanying cellular transformation. Cathepsin B was further validated for its expression in the three cell lines and in clinical samples of tumour tissues and their adjacent normal epithelia from 30 primary OSCC patients. Western blot analysis and real-time PCR detected increased Cathepsin B protein and mRNA levels in the cancerous HB56 and HB96 cells over HIOECs. Immunohistochemistry and real-time PCR showed elevated Cathepsin B protein and mRNA levels in the tumour tissues over the adjacent non-malignant epithelia from OSCC patients. The results presented here suggest that the expression of Cathepsin B increases along with the cancerisation in OSCC both in vitro and in vivo, and it may serve as a candidate biomarker of OSCC.     

Increased expression of Annexin A2 in oral squamous cell carcinoma

Previously, in vitro cellular carcinogenesis model of oral squamous cell carcinoma (OSCC) was established with a line of human immortalized oral epithelia cells (HIOECs), a line of cancerous HB96 cells, and another kind of cells (HB56 cells) at the early stage of carcinogenesis. In this study, comparative proteomic analysis identified a panel of differentially expressed proteins among these cells, and Annexin A2 shown as one of the significantly up-regulated proteins accompanying cellular transformation. Annexin A2 was further validated for its expression in the three kinds of cells and in the clinical samples of tumour tissues and their adjacent normal epithelia from primary OSCC patients. Western blot analysis and real-time PCR detected increased Annexin A2 protein and mRNA levels in cancerous HB56 and HB96 cells over HIOECs. Immunohistochemistry showed elevated Annexin A2 protein expression in tumour tissues over the adjacent non-malignant epithelia from OSCC patients; however, the mRNA levels between tumour and normal tissues did not change significantly. Interestingly, levels of Annexin A2 protein expression negatively correlated with the tumour differentiation grades. The results presented here suggest that Annexin A2 protein may play important roles in carcinogenesis of OSCC, and it may also serve as a candidate biomarker for pathologic differentiation grade of OSCC.     

Decreased expression of Annexin A1 correlates with pathologic differentiation grade in oral squamous cell carcinoma

Previously, we established an in vitro cellular carcinogenesis model of oral squamous cell carcinoma (OSCC), including the human immortalized oral epithelia cells (HIOECs) and its derived cancerous HB96 cells. In this study, comparative proteomic analysis identified that Annexin A1 was one of the significantly down-regulated genes in the cancerous HB96 cells. To investigate Annexin A1 down-regulation and its potential usefulness as a molecular marker in OSCC, we further screened Annexin A1 expressions with a panel of OSCC lines, and clinical samples of cancerous and the paired adjacent normal tissues from primary OSCC patients. By Western blot analysis and real-time PCR, we showed that both Annexin A1 mRNA and protein expressions decreased in OSCC cell lines except in two cell lines for the mRNA levels. Immunohistochemistry and real-time PCR also showed that both Annexin A1 mRNA and protein expressions decreased in the cancerous tissues from OSCC patients compared with those in the paired adjacent non-malignant epithelia. More importantly, both Annexin A1 mRNA and protein expressions negatively correlated with the pathologic differentiation grades of cancerous tissues. The lower Annexin A1 mRNA or protein expressions correlated with the poorer pathologic differentiation grades. These results suggest that decreased expression of Annexin A1 contributes to the cancerous progression of OSCC, and Annexin A1 may be a potential biomarker for pathologic differentiation grade of OSCC.     

Fos‐related activator‐1 is overexpressed in oral squamous cell carcinoma and associated with tumor lymph node metastasis

J Oral Pathol Med (2010) 39 : 470–476 Background: Previously, we established an in vitro cellular carcinogenesis model of oral squamous cell carcinoma (OSCC), including the human immortalized oral epithelia cells (HIOECs) and its derived cancerous HB cells. Then, expression microarray analysis showed that the gene encoding fos‐related activator‐1 (Fra‐1) was significantly upregulated in the cancerous HB cells compared with HIOECs. Methods: To confirm the expression of Fra‐1 at mRNA and protein levels by real‐time PCR and western blotting analysis in the carcinogenesis model of OSCC and CAL27 cells. To investigate Fra‐1 expression in clinical samples from 30 primary OSCC patients by immunohistochemistry. Results: Fra‐1 expression was increased both at mRNA and protein levels in this carcinogenesis model of OSCC and CAL27 cells. Nuclear and cytoplasmic Fra‐1 protein expressions both increased in the cancerous tissues compared with those in the paired adjacent non‐malignant epithelia (nuclear: P < 0.001, cytoplasmic: P = 0.003). A higher level of nuclear Fra‐1 expression was seen in the tumor samples of patients with lymph node metastasis than those without lymph node metastasis (5.07 ± 1.33 vs 3.81 ± 1.33, P = 0.023). Higher level of Fra‐1 expression was also found in the tumor invasive margin than tumor center. Conclusions: Fra‐1 is a positive gene of OSCC development and progression, Fra‐1 can be used as a potential therapeutic target gene and an additional marker for evaluation of lymph node metastasis.     

细胞角蛋白17在口腔鳞癌中的表达

目的 研究细胞角蛋白17(CK17)在口腔鳞癌中的表达,以期为口腔鳞癌的诊断和预防提供依据.方法 分别采用实时定量聚合酶链反应、免疫印迹方法和免疫组化方法检测口腔黏膜上皮体外癌变模型、口腔鳞癌细胞株及30例原发口腔鳞癌标本中的CKl7 mRNA及蛋白质的表达.结果 与永生化HIOEC细胞相比,CK17 mRNA在HB5...     

Characteristics of a cancerous cell line, HIOEC-B(a)P-96, induced by benzo(a)pyrene from human immortalized oral epithelial cell line

Oral squamous cell carcinoma (OSCC) is the most common malignant tumor in the oral and maxillofacial region. The mechanism of carcinogenesis of OSCC is still unclear. In vitro study on OSCC cell lines, especially derived from immortalized oral epithelial cells, is a very useful strategy to understand the mechanism of carcinogenesis. Based on our previous human immortalized oral epithelial cell (HIOEC) line, obtained from normal oral epithelial cells by transfection of HPV16 E6/E7 gene, a new cancerous cell line, HIOEC-B(a)P-96 (HB96), was established from the HIOEC by induction with benzo(a)pyrene. The characteristics of the HB96 cells such as cell morphology, ultrastructure, proliferation ability, invasion ability, and tumorigenesis were studied. The HB96 cells lost contact inhibition with uncontrolled cell division and obvious cell overlap, they were polygonal in shape and ununiform in size with increased ratio between nucleus and plasma. Increased proliferative ability and invasion ability were confirmed by the cell proliferation analysis and cell invasion assay, respectively. The tumorigenicity of well to moderately differentiated squamous cell carcinoma was confirmed in the nude mice experiments pathologically. Increased expression of HPV16 E6/E7 proteins and obvious correlation with decreased expression of p53 and Rb proteins was also confirmed by Western blotting. Thus, this HB96 cell line induced by benzo(a)pyrene from the HIOEC line is a useful tool to study the mechanism of carcinogenesis of OSCC in vitro for future genomic and proteomic analyses. It is also the first in vitro cancerous cell line of OSCC in China derived from immortalized oral epithelial cells.     

组织蛋白酶B在口腔黏膜上皮癌变过程中的表达及意义

目的：探讨组织蛋白酶B（Cathepsin B,CB）在口腔鳞状细胞癌中的表达及临床意义。方法：以口腔黏膜上皮永生化细胞系（human immortalized oral epithelia cell line,HIOEC）及经过苯丙芘[benzo（a）pyrene,B（a）P]诱导产生鳞状细胞癌细胞（HB）而形成的口腔鳞癌体外癌变模型为研究对象,通过双向凝胶电泳（2-DE）和质谱分析（LC-MS/MS）筛选和鉴定出差异蛋白质CB。采用实时定量PCR、Western印迹和免疫组化方法,检测口腔鳞癌细胞和30例原发口腔鳞癌标本中的mRNA及蛋白质表达水平。采用SPSS10.0软件包对数据进行非参数检验。结果：与永生化HIOEC相比,HB和CAL27细胞中CB的mRNA水平显著升高,HB、Tca8113、TSCC、CAL27和OSC细胞中CB蛋白表达水平明显升高。30例口腔鳞癌患者癌组织中CB的mRNA和蛋白表达水平均较癌旁组织升高（P〈0.01）。CB的表达水平与肿瘤大小、淋巴结转移、临床分期、病理分化程度无显著相关性。结论：CB在口腔鳞癌中的表达明显升高,提示其与肿瘤的发生、发展具有一定关系。     

Increased expression of focal adhesion kinase correlates with cellular proliferation and apoptosis during 4-nitroquinoline-1-oxide-induced rat tongue carcinogenesis

Background:  Oral carcinogenesis is a multistep process and requires accumulation and interplay of a series of molecular genetic events. Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that plays an important role in signalling pathways that are initiated at sites of integrin-mediated cell adhesions and by growth factor receptors. Overexpression of FAK has been linked to oral squamous cell carcinoma (OSCC). So, it is hypothesized that FAK expression might contribute to oral carcinogenesis.
Methods:  During 4-nitroquinoline-1-oxide-induced rat tongue carcinogenesis, FAK protein expression, proliferating cell nuclear antigen (PCNA) and apoptotic nuclei (TUNEL assay) were examined by means of immunohistochemistry.
Results:  Along with the progress of multistage carcinogenesis, FAK expression increased significantly among different histopathological groups with normal mucosa, mild-dysplastic epithelia, moderate-dysplastic epithelia, severe-dysplastic epithelia and in turn OSCC. Furthermore, FAK immunohistochemical index and PCNA-labelling index displayed positive correlation ( r  =   0.946, P  < 0.05), while negative associations were revealed between apoptotic index and final FAK index ( r  = −0.959, P  < 0.05).
Conclusion:  Our results implicated a role for FAK in oral carcinogenesis. Inhibition of FAK might be a potential novel treatment strategy in this disease.     

Expression of phosphorylated Akt in oral carcinogenesis and its induction by nicotine and alkaline stimulation

Background:  In Taiwan, it is well documented that cigarette smoking and areca nut chewing contribute to the risk of oral squamous cell carcinoma (OSCC). The role of phosphorylated Akt (p-Akt) in oral carcinogenesis induced by nicotine and alkaline environments was investigated.
Method:  Immunohistochemistry (IHC) was used to detect p-Akt expression in cancerous ( n  = 30) precancerous ( n  = 30), and normal mucosa tissues ( n  = 10). Western blotting was used to detect time-dependent induction of p-Akt by 100 μM nicotine in normal human bronchial epithelial cell (NHBE), normal human oral keratinocytes (NHOK), immortalized human epithelial cells (HaCaT) and OEC-M1 cells, dose-dependent induction of p-Akt in OEC-M1 and HaCaT cells and pH effect of p-Akt in OEC-M1. The unpaired t -test and the Fisher's exact test were used to analyze the p-Akt immunoreactivity in various groups and its association with clinicopathological parameters.
Results:  Higher p-Akt expression in cancerous group than in normal mucosa ( P  = 0.0002) and precancerous ( P  = 0.0049) groups was observed. A time-dependent increase in p-Akt in the NHBE, NHOK, HaCaT and OEC-M1 cell lines was observed with 100 μM nicotine treatment. The dose-dependent increase in p-Akt by nicotine treatment in HaCaT and OEC-M1 cells was obviously observed. Higher p-Akt expression in more alkaline environment (pH 8.0) was observed than at pH 7.4 in OEC-M1 cells.
Conclusion:  A potential role for increased p-Akt may relate to the dose and time of nicotine use. The potential role of an alkaline environment to enhance nicotine-related oral carcinogenesis may exist.     

口腔鳞癌与正常黏膜中细胞角蛋白基因13的表达

目的:研究细胞角蛋白基因13(cytokeratin13,CK13)在口腔鳞状细胞癌(oralsquamouscellcarcinoma,OSCC)组织中的表达及意义。方法:用RT-PCR方法检测30例OSCC患者肿瘤组织及其配对的正常黏膜中CK13mRNA的表达,同时用免疫组化方法检测CK13蛋白在OSCC及正常黏膜标本中的表达。所得数据采用Fisher确切概率计算法进行统计学处理。结果:RT-PCR检测结果表明,CK13mRNA在27例OSCC中的表达较其对照黏膜表达下调,平均下调4.2倍;免疫组化染色结果显示,CK13蛋白在正常口腔黏膜与肿瘤组织之间、高分化OSCC与中、低分化OSCC之间的表达差异具有统计学意义(P<0.05)。结论:在OSCC的发生、发展中,CK13基因的转录和表达水平发生明显变化,可能存在转录后水平的表达调控。CK13在OSCC分类诊断中有应用价值。     

半乳凝素1在口腔黏膜上皮癌变过程中的表达及意义

目的 探讨半乳凝素1( galectin-1)在口腔鳞状细胞癌(oral squamous cell carcinoma,OSCC)中的表达及临床意义,旨作为OSCC早期诊断的检测指标。方法分别采用实时定量聚合酶链反应(PCR)、蛋白质印迹法和免疫组化方法检测口腔黏膜上皮体外癌变模型、OSCC细胞系及30例原发OSCC标本中的半乳凝素1 mRNA及蛋白质的表达。结果半乳凝素1在永生化细胞系(humanimmortalized oral epithelia cell,HIOEC)中mRNA和蛋白相对表达量平均为0.071±0.023和0.118±0.046,与永生化细胞系HIOEC相比,半乳凝素1在所有检测的体外癌变模型和OSCC细胞系中mRNA和蛋白相对表达水平均升高,分别为0.141±0.049和0.504±0.33（P＜0.01）。30例OSCC组织中半乳凝素1 mRNA和蛋白相对表达量(0.059±0.034、1.5±0.68)均显著高于癌旁组织(0.029±0.012、0.4±0.56) (P＜O.01)。结论半乳凝素1在口腔黏膜上皮癌变过程中表达上调可能与OSCC的发生、发展有关,可作为OSCC早期诊断的检测指标。     

Loss of human β-defensin 1, 2, and 3 expression in oral squamous cell carcinoma

Introduction:  Human β-defensins (HBDs) are cationic, antimicrobial peptides produced by epithelial cells and involved in various aspects of the innate and acquired immune responses. They are expressed by oral tissues as constitutive and inducible genes. Recently, single nucleotide polymorphisms (SNPs) of β-defensins have been correlated with increased susceptibility to certain diseases. Studies have reported altered expression of β-defensins in cancers suggesting their involvement in carcinogenesis. The purpose of this study was to evaluate the regulation of HBD-1 (also published as DEFB1), HBD-2 (DEFB4) and HBD-3 (DEFB103A) ( http://www.genenames.org/index.html ) and HBD-1 SNPs in oral squamous cell carcinoma cell lines (OSCC) and healthy gingival keratinocytes.
Methods:  β-defensin expression was quantitatively assessed using real-time polymerase chain reactions in OSCC and control cell lines after exposure to interleukin-1β, tumor necrosis factor-α, and interferon-γ. Control data were obtained in a previous study. DNA from 19 OSCC cell lines and 44 control subjects were extracted and the HBD-1 region spanning the 5' untranslated region to the first intron was sequenced and analysed for SNP identification and distribution.
Results:  HBD-1 and HBD-2 basal messenger RNA expression were significantly lower in OSCC. In addition, the ability to be induced was significantly reduced in OSCC for all three β-defensins. Four HBD-1 SNPs were differentially distributed between cancer and control populations. Genotype distribution at the HBD-1 locus also suggested loss of heterozygosity in OSCC.
Conclusions:  The genetic variation observed in OSCC compared with that in control cell lines may account for differences in β-defensin expression. These results suggest a putative role for β-defensins in carcinogenesis and indicate that β-defensins may be useful markers of OSCC.     

细胞角蛋白19mRNA在口腔鳞状细胞癌中表达的研究

目的探讨口腔鳞状细胞癌（OSCC）患者癌组织中细胞角蛋白（CK）19 mRNA的变化和其发生的可能机制以及CK19 mRNA检测的临床应用价值。方法收集未接受过放疗和化疗的20例OSCC患者的手术标本（包括癌组织20块、癌旁组织20块和颈清扫的淋巴结43枚）,采用荧光定量聚合酶链式反应（FQ-PCR）法检测组织内CK19 mRNA的表达,比较CK19 mRNA在上述组织中的相对表达量。结果CK19 mRNA在OSCC癌组织内表达比其在正常口腔黏膜内表达高1.85倍,比其在癌旁组织内表达高1.66倍。9例患者颈清扫淋巴结内CK19 mRNA表达阳性,阳性率为45%（9/20）,而9例患者的22枚淋巴结中CK19 mRNA表达阳性率是81.8%（18/22）,占20例患者43枚淋巴结的41.9%（18/43）。淋巴结CK19 mRNA阳性患者的癌组织与癌旁组织和正常口腔黏膜的表达量比CK19 mRNA阴性患者低。结论CK19 mRNA在OSCC癌组织中的表达高于其在癌旁组织和正常口腔黏膜内的表达,可能是由于癌组织中CK19的合成明显增加所致。淋巴结中CK19 mRNA的表达可以作为检测OSCC淋巴结微转移的指标之一,运用FQPCR法检测淋巴结中CK19 mRNA的表达来检测OSCC的淋巴结微转移比普通病理法检测更灵敏。     

细胞角蛋白19和间隙连接蛋白43在4-亚基硝氧喹啉诱发大鼠舌黏膜癌变过程中表达的研究

目的 研究4-亚基硝氧喹啉（4NQO）诱发大鼠口腔黏膜癌变过程中细胞角蛋白19（CK19）和间隙连接蛋白43（Cx43）的表达,探讨口腔黏膜癌变过程中CK19与Cx43的相关性。方法 利用4NQO诱导SD大鼠的口腔黏膜癌变,运用免疫组织化学的方法检测CK19、Cx43在口腔黏膜癌变过程中各阶段的动态变化。结果 在大鼠正常舌黏膜组织中,CK19阳性染色的细胞散在分布于黏膜基底层;随着大鼠舌黏膜上皮异常增生程度的增加,CK19表达于黏膜基底上层;在口腔鳞状细胞癌（OSCC）组织中,CK19阳性染色细胞分布在黏膜各层。CK19在正常舌黏膜、轻度上皮异常增生、中度上皮异常增生、重度上皮异常增生、OSCC组织中阳性表达率分别为30.00%、50.00%、58.33%、80.00%、91.67%,差异有统计学意义（P<0.05）。在正常舌黏膜中Cx43蛋白主要表达于大鼠舌黏膜上皮细胞的细胞膜上,上皮的基底层、棘层和颗粒层呈阳性染色。随着大鼠舌黏膜上皮异常增生程度的增加,Cx43的表达明显下降。Cx43在正常舌黏膜、轻度上皮异常增生、中度上皮异常增生、重度上皮异常增生、OSCC组织中阳性表达率分别为100.00%、85.71%、66.67%、40.00%、33.33%,差异有统计学意义（P<0.05）。结论 在大鼠舌黏膜癌变过程中,CK19蛋白表达水平随病变程度加重显著升高,提示CK19与口腔上皮细胞的癌变有关;Cx43蛋白表达水平随病变程度加重显著下降,Cx43表达下降是口腔黏膜癌变的早期事件。CK19与Cx43蛋白表达呈负相关,CK19和Cx43的联合检测对OSCC的早期诊断有重要的作用,有利于提高OSCC早期诊断的灵敏度和特异性。     

Expression of p16 in oral cancer and premalignant lesions

Background:  Expression of p16 has been proposed as a marker for malignant transformation. This study aimed to evaluate p16 expression in oral squamous cell carcinoma (OSCC) and premalignant lesions including oral leukoplakia (OL) with and without dysplasia.
Methods:  Expression of p16 was investigated in 56 samples including OSCC, OL with and without dysplasia, and normal oral mucosa. Expression of p16 was identified by immunohistochemistry, using the CINtecTM p16INK4a Histology Kit. Both nuclear and/or cytoplasmic staining of the keratinocytes were considered to be positive and the percentage of positive cells was calculated.
Results:  Expression of p16 was detected in 3/16 (18.75%) cases of OSCC, in 4/15 (26.7%) cases of OL without dysplasia, and in none of OL with dysplasia and normal mucosa. No significant differences in p16 expression prevalence were found among OSCC, OL with and without dysplasia and normal mucosa. The percentages of positive cells in OSCC and OL without dysplasia were 0.89 and 0.17, respectively. No significant difference in the percentage of positive keratinocytes was found.
Conclusion:  As a marker, p16 is not reliable for oral mucosal dysplasia and malignant transformation.     

Effects of small interfering RNAs targeting Fascin on gene expression in oral cancer cells

Background:  Oral squamous cell carcinoma (OSCC) is one of the most common head and neck cancers. The prognosis of OSCC is usually poor because of extensive local invasion at initial diagnosis. In the literature, Fascin has been reported responsible for cell motility and over-expression of Fascin contributes to an unfavorable clinical course. Nevertheless, the roles of Fascin protein playing in aggressiveness of OSCC and their potential mechanisms need to be elucidated.
Methods:  Two cell lines of OSCC (OECM-1 and SCC-25) via the vector-based small interfering RNA (siRNA) to suppress the expression of the Fascin gene were used. Subsequent analyses and observation regarding the expression of Fascin protein and cyto-morphological alterations were detected by Western blot and immunofluorescent microscopy. Boyden chamber invasion assay, cell migration assay and adhesion assay were also applied to investigate the functional changes of OSCC.
Results:  There were statistically significant differences ( P  < 0.05) of Fascin expression before and after silencing. Down-regulation of Fascin protein directly led to changes of cell surface protrusions under immunofluorescent microscopy and resulted in suppression of migration, invasion and increase of adhesion in both cell lines ( P  < 0.05). Furthermore, down-regulation of Fascin expression also resulted in alterations of E-cadherin, β-catenin and TWIST at certain level, implicative of an association with epithelial-mesenchymal transition (EMT).
Conclusions:  Our results suggest that expression of Fascin protein may play an essential role in regulation of progression of OSCC and contributes to the event of EMT in the early aggressiveness of OSCC.     

Promoter hypermethylation of mismatch repair genes, hMLH1 and hMSH2 in oral squamous cell carcinoma

Objectives:  Major risk factors of oral squamous cell carcinoma (OSCC) are environmental and can lead to DNA mutagenesis. Mismatch repair (MMR) system functions to repair small DNA lesions, which can be targeted for promoter hypermethylation. We therefore wanted to test whether hypermethylation of MMR genes ( hMLH1, hMSH2 ) could contribute to oral carcinogenesis by correlating the information to patient clinical data.
Methods:  Genomic DNA was extracted from 28 OSCC and six normal oral epithelium samples. The methylation status of the two MMR genes was assessed using Methylation Specific PCR after DNA modification with sodium bisulfite. Serial sections of the same tissues were immunostained with antibodies against hMLH1 and hMSH2 protein.
Results:  Promoter hypermethylation was observed in 14/28 OSCC cases. Remarkably, 100% of patients with multiple oral malignancies showed hypermethylation in hMLH1 or hMSH2 compared with 31.5% of single tumor patients. In 10 cancer cases, expression of the hMLH1 and hMSH2 genes by immunostaining showed reduced or absence of expression of one of the genes, although some did not reflect the methylation status.
Conclusions:  Hypermethylation of hMLH1 and hMSH2 might play a role in oral carcinogenesis and may be correlated with a tendency to develop multiple oral malignancies.     

CXCR-4 knockdown by small interfering RNA inhibits cell proliferation and invasion of oral squamous cell carcinoma cells

Background:  Oral squamous cell carcinomas (OSCCs) are characterized by a high degree of local invasion and a high rate of metastases to cervical lymph nodes. Downregulation of CXCR-4 by siRNA inhibits invasion and growth of breast and colon cancer cells. However, there have been no reports on the downregulation of CXCR-4 by small interfering RNA (siRNA) in oral cancer cells.
Methods:  We generated two stable CXCR-4-knockdown clones (KBsi and KOSCC-25Bsi) from the KB and KOSCC-25B OSCC cell lines by lentiviral delivery. In vitro invasion and cell proliferation assays were used to investigate the effect of CXCR-4 downregulation on cell proliferation and invasiveness in KBsi and KOSCC-25Bsi. Immunohistochemistry was performed to evaluate the correlation between CXCR-4 expression and proliferation in 26 OSCC tissue samples.
Results:  CXCR4-knockdown OSCC cells showed reduced invasiveness. The invasiveness of KBsi decreased to 29.5% of the vector-infected controls, and KOSCC-25Bsi decreased to 38.1% of the control vector-infected cells ( P  <   0.05). The CXCR4-knockdown OSCC cells grew significantly slower than the vector-infected control cells. KBsi and KOSCC-25Bsi cells proliferated at 69.5% and 71.7%, respectively, of the rate of control vector-infected cells ( P  <   0.05). CXCR-4-positive group had significantly higher PCNA labeling index than CXCR-4-negative group in OSCC tissue samples.
Conclusion:  These results suggest that the downregulation of CXCR-4 induces anti-proliferative and anti-invasive effects in OSCC and that CXCR-4 might be a useful target molecule for the treatment of OSCC.     

Role of TP53 in the progression of pre-malignant and malignant oral mucosal lesions. A follow-up study of 144 patients

Background:  Prediction of progression from pre-malignant oral mucosal lesions to malignancy, or recurrence of an existing oral squamous cell carcinoma (OSCC), is an important clinical problem in oral medicine.
Methods:  This study presents a follow-up of a study published in 2002. Samples from 54 patients with OSCC, 45 with oral lichen planus (OLP) and 45 with hyperkeratosis (clinically leukoplakia), diagnosed between 1987 and 1996, were analysed for TP53 protein expression and TP53 mutation. Follow-up was 11–17 years for OSCC (mean 13.3), 12–22 years for OLP (mean 15.9) and 12–17 years for hyperkeratosis (mean 14.5).
Results:  Of the 54 OSCC patients, 28 experienced recurrent disease, 21 died of OSCC, 22 died of other causes. Of the 14 OSCC patients with mutated TP53 ( n  = 11), the cancer recurred in eight (57%) and in 20/39 (51%) without mutation. Expression of TP53 protein was significantly associated with reduced overall survival. Among OLP patients, nine were TP53- mutated out of 31 tested. One TP53- mutated OLP patient developed OSCC in a different site. Of the hyperkeratosis patients, three were mutated of 22 tested. One hyperkeratosis patient (non-mutated) developed OSCC in the same site.
Conclusion:  TP53 mutations can exist in benign oral mucosal lesions for many years without progression to malignancy. No association was found between TP53 protein expression or TP53 mutation and recurrence of OSCC or disease-related survival. Overall survival was reduced in patients with positive TP53 protein expression.