Progressive increase of human papillomavirus carriage rates in potentially malignant and malignant oral disorders with increasing malignant potential

Introduction:  We investigated the potential role of human papillomaviruses (HPVs) in potentially malignant oral disorders, oral leukoplakia (OL) and oral lichen planus (OLP), and in oral squamous cell cancer (OSCC) in an Eastern Hungarian population with a high incidence of OSCC.
Methods:  Excised tumor samples (65 OSCC patients) and exfoliated cells from potentially malignant lesions (from 44 and 119 patients with OL and OLP, respectively) as well as from healthy controls (72 individuals) were analysed. OLPs were classified based on clinical appearance, 61 patients had erosive–atrophic lesions (associated with higher malignancy risk, EA-OLP) and 58 had non-erosive non-atrophic lesions (with lower risk of becoming malignant, non-EA-OLP), respectively. Exfoliated cells collected from apparently healthy mucosa accompanied each lesion sample. HPV was detected by MY/GP polymerase chain reaction (PCR) and genotyped by restriction analysis of amplimers. Copy numbers in lesions were determined using real-time PCR. Prevalence rates, copy number distributions, and association with risk factors and diseases were analysed using chi-square test, t -test, and logistic regression, respectively.
Results:  We detected HPVs significantly more frequently in lesions than in controls ( P  ≤ 0.001 in all comparisons). HPV prevalence increased gradually with increasing severity of lesions (32.8, 40.9, and 47.7% in OLP, OL, and OSCC, respectively). Copy number distribution patterns roughly corresponded to prevalence rates, but OLP and OL were comparable. HPV prevalence differed significantly between EA-OLP and non-EA-OLP groups (42.6 vs. 22.4%); EA-OLP group showed a prevalence similar to that found in OL.
Conclusion:  HPVs may be involved in the development or progression of not only OSCC but also of potentially malignant oral lesions.     

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.     

E‐cadherin downregulation and Twist overexpression since early stages of oral carcinogenesis

There is some evidence of Twist participation in oral carcinogenesis; however, little is known about its interaction with E‐cadherin in oral squamous cell carcinoma (OSCC) development. This experimental study included an immunohistochemical analysis of Twist and E‐cadherin proteins in paraffin‐embedded specimens of oral leukoplakia (OL), OSCC, and normal oral mucosa. In addition, it was also performed a Western blot and double‐immunofluorescence analysis of Twist and E‐cadherin expression in OSCC cell lines. Significant differences in Twist and E‐cadherin immunoexpression were observed between normal oral mucosa and OL, with an inverse relation since the earliest stages of oral dysplasia (r = ?0,512; P < 0.001). Western blot and double‐immunofluorescence analysis showed differences in Twist and E‐cadherin expression among human oral keratinocytes and OSCC cell lines suggesting that downregulation of E‐cadherin occurs in a dependent manner of Twist in OSCC. Our results showed a possible value of Twist and E‐cadherin in the prediction of risk of oral epithelium malignant transformation.     

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.     

Prognostic significance of Bcl-2 and Bax protein expression in the patients with oral squamous cell carcinoma

Background:  The aim of this study was to investigate the expression of the apoptosis-inhibitory Bcl-2 protein and the apoptosis-promoting Bax protein and to identify their association with the clinical parameters and prognosis of the patients with oral squamous cell carcinoma (OSCC).
Methods:  The expression of Bcl-2 and Bax proteins was evaluated by immunohistochemical staining in specimens from 110 patients with OSCC. Every section was scored according to both the percentage of positive staining tumor cells and the staining intensity. The Kaplan-Meier test and Cox proportional hazards regression analysis were performed to assess the correlation between the protein levels and the long survival rate of patients. The association between Bax, Bcl-2 immunoexpression and clinicopathologic variables was analyzed with the chi-square test and non-parametric analysis. The Bcl-2 and Bax immunoexpression in 20 oral mucosa samples were also investigated as normal control.
Results:  The results showed that the 5-year survival rate was significantly higher in the patients with the ratio of Bcl-2/Bax ≤ 1 than in those with Bcl-2/Bax > 1 (76.79 ± 6.69% vs. 59.26 ± 6.69%, P  = 0.0489). Bax immunoreactivity was significantly correlated with histological grading and lymph node metastasis. Univariate analysis indicated that the ratio of Bcl-2/Bax and lymph node metastasis were two independent factors related to the prognosis.
Conclusion:  The ratio of Bcl-2/Bax could be used as an effective biomarker to predict the prognosis of OSCC.     

Stromal myofibroblasts in oral leukoplakia and oral squamous cell carcinoma

Objectives: Oral leukoplakia (OL) is the main potentially malignant disorder and oral squamous cell carcinoma (OSCC) is the most common malignancy of the oral mucosa. Stromal myofibroblasts play an important role in tumor invasion and metastasis, due to its ability to modify the extracellular matrix. This study aimed to evaluate the presence of stromal myofibroblasts in OL and OSCC. Differences in the presence of myofibroblasts among OL with distinct grades of epithelial dysplasia as well as between histologically high- and low-invasive OSCC were also assessed. Study Design: A total of 30 OL and 41 OSCC from archival formalin-fixed, paraffin-embedded specimens were evaluated. 10 samples of normal oral mucosa were used as a control. Myofibroblasts were identified by immunohistochemical detection of alpha smooth muscle actin and its presence was classified as negative, scanty or abundant. Differences in the presence of myofibroblasts among OL with distinct grades of epithelial dysplasia as well as between high- and low-invasive OSCC were analyzed using the Mann-Whitney test. Results: Myofibroblasts were not detected in normal oral mucosa and OL, whatever its histological grade. In OSCC, the presence of stromal myofibroblasts was classified as negative in 11 (26.8%), scanty in 15 (36.6%), and abundant in 15 samples (36.6%). The presence of stromal myofibroblasts was statistically higher in high-invasive OSCC than in low-invasive OSCC (p<0.05). Conclusions: Stromal myofibroblasts were not detected in OL, indicating that these cells are not important during oral carcinogenesis. Nevertheless, stromal myofibroblasts were heterogeneously detected in OSCC and its presence was higher in tumors with a more diffuse histological pattern of invasion. These findings suggest that myofibroblasts are associated with the creation of a permissive environment for tumor invasion in OSCC. Key words:Leukoplakia, oral squamous cell carcinoma, myofibroblast.     

诱导型一氧化氮合酶表达在口腔癌前病变口腔鳞癌发展过程中的作用研究

目的　探讨诱导型一氧化氮合酶 (iNOS)在口腔癌前病变、口腔鳞癌发展过程中的表达情况及其作用。方法　采用免疫组化SABC法检测 10例正常口腔黏膜、8例上皮单纯增生、2 0例上皮异常增生和 3 2例鳞状细胞癌组织中iNOS的表达。结果　正常口腔黏膜iNOS阴性表达 ;上皮异常增生组和鳞癌组中iNOS的表达较上皮单纯增生组均显著增加 (P <0 .0 5 ) ;随着上皮异常增生程度的加重 ,iNOS的标记指数逐级显著上升 (P <0 .0 5 ) ;上皮异常增生组与鳞癌组之间以及鳞癌的各病理分级之间iNOS的表达均无显著性差异 (P >0 .0 5 )。结论　iNOS的表达可能参与了口腔鳞癌的衍进过程     

Stromal myofibroblasts in oral leukoplakia and oral squamous cell carcinoma

Objectives: Oral leukoplakia (OL) is the main potentially malignant disorder and oral squamous cell carcinoma (OSCC) is the most common malignancy of the oral mucosa. Stromal myofibroblasts play an important role in tumor invasion and metastasis, due to its ability to modify the extracellular matrix. This study aimed to evaluate the presence of stromal myofibroblasts in OL and OSCC. Differences in the presence of myofibroblasts among OL with distinct grades of epithelial dysplasia as well as between histologically high- and low-invasive OSCC were also assessed. Study Design: A total of 30 OL and 41 OSCC from archival formalin-fixed, paraffin-embedded specimens were evaluated. 10 samples of normal oral mucosa were used as a control. Myofibroblasts were identified by immunohistochemical detection of alpha smooth muscle actin and its presence was classified as negative, scanty or abundant. Differences in the presence of myofibroblasts among OL with distinct grades of epithelial dysplasia as well as between high- and low-invasive OSCC were analyzed using the Mann-Whitney test. Results: Myofibroblasts were not detected in normal oral mucosa and OL, whatever its histological grade. In OSCC, the presence of stromal myofibroblasts was classified as negative in 11 (26.8%), scanty in 15 (36.6%), and abundant in 15 samples (36.6%). The presence of stromal myofibroblasts was statistically higher in high-invasive OSCC than in low-invasive OSCC (p<0.05). Conclusions: Stromal myofibroblasts were not detected in OL, indicating that these cells are not important during oral carcinogenesis. Nevertheless, stromal myofibroblasts were heterogeneously detected in OSCC and its presence was higher in tumors with a more diffuse histological pattern of invasion. These findings suggest that myofibroblasts are associated with the creation of a permissive environment for tumor invasion in OSCC.     

P53 and bcl-2 immunoexpression in patients with oral lichen planus and oral squamous cell carcinoma

Objective: The aim of this study was to determine by immunohistochemistry the presence and significance of p53 and bcl-2 proteins in oral lichen planus (OLP) and oral squamous cell carcinoma (OSCC). Study Design: We used 21 cases diagnosed as OLP 16 diagnosed as OSCC and four normal gingival biopsies taken from healthy patients were used as controls. Slides were processed for immunohistochemistry using anti-p53 and anti-bcl-2 monoclonal antibodies. Results: We found p53 immunoexpression in 71.4% OLP cases and 68.7% OSCC cases, with no immunoexpression in control cases. Bcl-2 was negative for all OLP and OSCC cases, and mild positivity was observed in normal tissue. We found significant correlation among p53 expression and OSCC malignancy. Conclusions: Our results suggest that TP53 system mainly promotes a hyperproliferative state by cell cycle arrest of the OLP epithelial cells for repairing damaged DNA nor apoptosis and that anti-apoptotic action of bcl-2 is not important in this disease. Key words:Oral lichen planus, oral squamous cell carcinoma, p53, Bcl-2, carcinogenesis, malignant transformation.     

P21/ WAF1 and cyclin D1 variants and oral squamous cell carcinoma

Background:  Genetic factors are known to be involved in oral squamous cell carcinoma (OSCC) development.
Method:  We evaluated a possible association between CCND1 A870G and P21/WAF1 C98A polymorphisms and OSCC, as well as the impact of the genotypes on protein immunoexpression. The study group consisted of 80 individuals with histopathological diagnosis of OSCC and the control group consisted of 80 healthy individuals without oral lesions and matched by age, sex and tobacco usage. The genotypes were studied by the polymerase chain reaction and restriction fragment length polymorphic analysis. Paraffin-embedded sections were used for immunohistochemical analysis.
Results:  No statistical association between CCND1 and/or P21/WAF1 genotypes and OSCC was demonstrated, although we found that people harbouring the combined presence of at least one variant allele of both genes showed a 1.8 times more chance of developing OSCC compared to the referent genotype. OSCC tumours from individuals with P21 heterozygous genotype showed a significantly higher immunopositivity than tumours from wild-type individuals.
Conclusion:  The present study did not demonstrate a significant association between CCND1 and / or P21 / WAF1 genotypes and OSCC. However, P21 protein expression in OSCC tumours is affected by P21 / WAF1 genotype.     

Alteration in the expression of cdk4 and cdk6 proteins in oral cancer and premalignant lesions

J Oral Pathol Med (2010) 39 : 793–799 Background: Cdk4 and cdk6, key players in G1 phase, have been shown to play an important role in the development of oral squamous cell carcinoma (OSCC). This study investigated the expression of these two proteins in OSCC and premalignant lesions including oral leukoplakia (OL) with and without dysplasia and determined if alterations in the expression of these two proteins could be used as markers of malignant transformation. Methods: Expressions of cdk4 and cdk6 were evaluated in 61 samples including OSCC, OL with and without dysplasia and normal oral mucosa using immunohistochemistry method. Nuclear staining of the keratinocytes was considered positive and the percentage of positive cells was calculated. Results: Expression of cdk4 was found in 11/15 (73.33%) OSCC, 13/14 (92.85%) OL with dysplasia, 13/20 (65%) OL without dysplasia and 3/12 (25%) normal mucosa. Expression of cdk6 was detected in 9/15 (60%) OSCC, 3/14 (21.43%) OL with dysplasia, 5/20 (25%) OL without dysplasia and 1/12 (8.33%) normal mucosa. In cdk4 stained specimens, the frequency of positive cases and the percentage of positive cells in normal mucosa was significantly lower than OL with dysplasia and OSCC. For cdk6 staining, the prevalence of positive cases and the percentage of positive cells in normal mucosa were significantly lower than OSCC. Conclusions: Overexpressions of cdk4 and cdk6 were observed in OSCC, indicating that these two proteins play a crucial role in OSCC. The aberrant expression of cdk4 was found in OL with dysplasia, suggesting that cdk4 may be involved in the early event of carcinogenesis.     

Decreased expression of Ep-CAM protein is significantly associated with the progression and prognosis of oral squamous cell carcinomas in Taiwan

Background:  The epithelial cell adhesion molecule (Ep-CAM) is involved in cell signaling, migration, proliferation, cell-cycle regulation, and cancer metastasis.
Methods:  This study used an immunohistochemical technique to examine the expression of Ep-CAM protein in 84 specimens of oral squamous cell carcinoma (OSCC), 98 specimens of oral epithelial dysplasia (OED, 31 mild, 41 moderate, and 26 severe OED cases), and 15 specimens of normal oral mucosa (NOM).
Results:  We found that the mean Ep-CAM labeling indices (LIs) decreased significantly from NOM (80 ± 18%) and mild OED (76 ± 14%) through moderate OED (66 ± 22%) and severe OED (55 ± 20%) to OSCC samples (46 ± 16%, P <  0.001). A significant correlation was found between the lower mean Ep-CAM LI and OSCCs with larger tumor size ( P =  0.003), positive lymph node metastasis ( P =  0.022), more advanced clinical stages ( P <  0.001), cancer recurrence ( P =  0.021), or extracapsular spread of lymph node ( P =  0.015). However, only Ep-CAM LI  <  50% ( P  < 0.0001) was identified as an independent unfavorable prognosis factor by multivariate analyses with Cox proportional hazard regression model. Kaplan–Meier curve showed that OSCC patients with an Ep-CAM LI < 50% had a significantly poorer cumulative survival than those with an Ep-CAM LI ≥ 50% ( P  < 0.00001, log-rank test).
Conclusions:  We conclude that the decreased expression of Ep-CAM protein is an early event in oral carcinogenesis. The Ep-CAM LI in OSCC samples can predict the progression of OSCCs and the survival of OSCC patients.     

RNA from brush oral cytology to measure squamous cell carcinoma gene expression

Background:  RNA expression analysis of oral keratinocytes can be used to detect early stages of disease such as oral cancer or to monitor on-going treatment responses of the same or other oral diseases. A limitation is the inability to obtain high quality RNA from oral tissue without using biopsies. While oral cytology cell samples can be obtained from patients in a minimally invasive manner they have not been validated for quantitative analysis of RNA expression.
Methods:  As a starting point in the analysis of tumor markers in oral squamous cell carcinoma (OSCC), we examined RNA in brush cytology samples from hamsters treated with dibenzo[a,l]pyrene to induce oral carcinoma. Three separate samples from each animal were assessed for expression of candidate marker genes and control genes measured with real-time RT-PCR.
Results:  Brush oral cytology samples from normal mucosa were shown to consist almost exclusively of epithelial cells. Remarkably, ß-2 microglobulin and cytochrome p450, 1B1 (CYP1B1) RNA showed potential utility as markers of OSCC in samples obtained in this rapid and non-surgical manner.
Conclusion:  Brush oral cytology may prove useful as a source of RNA for gene expression analysis during the progression of diseases of the oral epithelium such as OSCC.     

Detection of survivin mRNA in healthy oral mucosa, oral leucoplakia and oral cancer

Background:  Survivin is involved in modulation of cell death and cell division processes. Survivin expression in normal adult tissues has not been fully understood, although it is markedly lower than in cancer, where it is over-expressed.
Objective:  To investigate survivin expression in normal, potentially malignant and cancerous oral mucosa.
Methods:  We measured survivin mRNA levels by real-time RT-PCR in specimens of oral mucosa (15 from normal mucosa, 17 from potentially malignant lesions, 17 from neoplasms). Scores were compared using Kruskal–Wallis test and post hoc according to Conover. Chi-squared test was used for dichotomous data.
Results:  The median relative levels of survivin mRNA resulted six for normal mucosa, eight for potentially malignant lesions, 13 for cancers: differences among these three groups were statistically significant, as between cancer and potentially malignant lesions. Expression in normal mucosa and potentially lesions group showed no significant difference. Low, but not marginal expression of survivin in normal mucosa is a new finding, and it could be explained with the higher sensibility of our methods.
Conclusions:  Survivin expression in oral potentially malignant lesions might indicate a progressive deregulation of expression paralleling oncogenesis, particularly during the first stages of process, suggesting a putative predictive role for survivin.     

Immunohistochemical expression of p53, p16 and hTERT in oral squamous cell carcinoma and potentially malignant disorders

Oral carcinogenesis is a multi-step process. One possible step is the development of potentially malignant disorders known as leukoplakia and erytroplakia. The objective of this study was to use immunohistochemistry to analyze the patterns of expression of the cell-cycle regulatory proteins p53 and p16(INK4a) in potentially malignant disorders (PMD) of the oral mucosa (with varying degrees of dysplasia) and in oral squamous cell carcinomas (OSCC) to correlate them with the expression of telomerase (hTERT). Fifteen PMD and 30 OSCC tissue samples were analyzed. Additionally, 5 cases of oral epithelial hyperplasia (OEH) were added to analyze clinically altered mucosa presenting as histological hyperplasia without dysplasia. p53 positivity was observed in 93.3% of PMD, in 63.3% of OSCC and in 80% of OEH. Although there was no correlation between p53 expression and the grade of dysplasia, all cases with severe dysplasia presented p53 suprabasal immunoexpression. p16(INK4a) expression was observed in 26.7% of PMD, in 43.3% of OSCC and in 2 cases of OEH. The p16(INK4a) expression in OEH, PMD and OSCC was unable to differentiate non-dysplastic from dysplastic oral epithelium. hTERT positivity was observed in all samples of OEH and PMD and in 90% of OSCC. The high hTERT immunoexpression in all three lesions indicates that telomerase is present in clinically altered oral mucosa but does not differentiate hyperplastic from dysplastic oral epithelium. In PMD of the oral mucosa, the p53 immunoexpression changes according to the degree of dysplasia by mechanisms independent of p16(INK4a) and hTERT.     

P53 and bcl-2 immunoexpression in patients with oral lichen planus and oral squamous cell carcinoma

Objective: The aim of this study was to determine by immunohistochemistry the presence and significance of p53 and bcl-2 proteins in oral lichen planus (OLP) and oral squamous cell carcinoma (OSCC). Study Design: We used 21 cases diagnosed as OLP 16 diagnosed as OSCC and four normal gingival biopsies taken from healthy patients were used as controls. Slides were processed for immunohistochemistry using anti-p53 and anti-bcl-2 monoclonal antibodies. Results: We found p53 immunoexpression in 71.4% OLP cases and 68.7% OSCC cases, with no immunoexpression in control cases. Bcl-2 was negative for all OLP and OSCC cases, and mild positivity was observed in normal tissue. We found significant correlation among p53 expression and OSCC malignancy. Conclusions: Our results suggest that TP53 system mainly promotes a hyperproliferative state by cell cycle arrest of the OLP epithelial cells for repairing damaged DNA nor apoptosis and that anti-apoptotic action of bcl-2 is not important in this disease.     

Polymorphisms in the apoptosis‐associated genes FAS and FASL and risk of oral cancer and malignant potential of oral premalignant lesions in a Taiwanese population

J Oral Pathol Med (2010) 39: 155–161 Background: Our aim was to measure the relationship of FAS (?1377G>A and ?670A>G), FASL (?844C>T) gene variants and risk of oral cancer. Methods: Polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) analysis was used to determine the FAS and FASL polymorphisms in 294 oral squamous cell carcinoma (OSCC), 53 oral submucous fibrosis (OSF), and 84 oral leukoplakia (OL) patients, as well as in 333 healthy controls. A standardized questionnaire was applied to collect demographic data, and potential confounding factors. JMP statistical software was used to analyze the association. Results: FAS and FASL polymorphisms were not correlated with OSCC development or the malignant potential of OL by simple and multivariate logistic regression. However, a two‐ to fourfold difference in the risks of betel quid chewing, alcohol consumption, and smoking on OSCC development were observed between participants with different FAS polymorphisms. FAS polymorphisms were significantly correlated with the malignant potential of OSF. Multivariate logistic regression analysis indicated that FAS A_?1377‐G_?670 vs. G_?1377‐A_?670 haplotype (OR = 2.26, 95% CI = 1.16–4.41) was correlated with the malignant potential of OSF. Conclusions: We suggest that FAS and FASL polymorphisms are not significantly correlated with OSCC development or malignant potential of OL. The impact of substance usage on OSCC development could be differentiated by FAS polymorphisms. FAS A_?1377‐G_?670 haplotype may play a role in the malignant potential of OSF.     

Overexpression of cytokeratin 17 protein in oral squamous cell carcinoma in vitro and in vivo

Objective:  To determine the cytokeratin 17 (CK17) expression in oral squamous cell carcinoma (OSCC) both in vitro and in vivo .
Methods:  Comparative proteomic analysis of an in vitro cellular carcinogenesis model of OSCC (including 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 was performed to identify differentially expressed proteins. CK17 was further validated in vitro (cellular carcinogenesis model and other three OSCC lines) and in vivo (tissues from six healthy persons and 30 primary OSCC patients) by Western blotting and immunohistochemistry respectively.
Results:  Increased CK17 expression was identified by two-dimensional gel electrophoresis and liquid chromatography–tandem mass chromatography in the HB56 and HB96 cells over HIOECs. Western blotting confirmed the increased CK17 expression in the HB56, HB96 cells and other three OSCC lines. Immunohistochemistry confirmed the increased CK17 expression in the cancerous tissues from OSCC patients compared with the paired adjacent non-malignant epithelia.
Conclusion:  Increased CK17 expression may play an important role in the carcinogenesis progression of OSCC; however, further studies on the molecular function of CK17 are encouraged to clear the precise mechanism of CK17 in OSCC.     

Expression of hypoxia-inducible factor-1α is significantly associated with the progression and prognosis of oral squamous cell carcinomas in Taiwan

Background:  Overexpression of hypoxia-inducible factor-1α (HIF-1α) has been found to be significantly associated with the tumor invasion, lymph node metastasis, clinical stage, and prognosis of a variety of human cancers.
Methods:  This study examined the expression of HIF-1α in 57 specimens of oral squamous cell carcinoma (OSCC), 41 specimens of oral epithelial dysplasia (OED, 12 mild, 17 moderate, and 12 severe OED cases), and 14 specimens of normal oral mucosa (NOM) by immunohistochemistry.
Results:  We found that the mean nuclear HIF-1α labeling indices (LIs) increased significantly from NOM (9 ± 6%) through mild OED (25 ± 18%), moderate OED (41 ± 27%), and severe OED (42 ± 22%) to OSCC samples (55 ± 23%, P  < 0.001). A significant correlation was found between the higher mean nuclear HIF-1α LI and OSCCs with larger tumor size ( P  < 0.001), regional lymph node metastasis ( P  < 0.001), or more advanced clinical stages ( P  < 0.001). Only larger tumor size ( P  = 0.002) and nuclear HIF-1α LI ≥ 60% ( P  = 0.048) were identified as independent unfavorable prognosis factor by multivariate analyses with Cox regression model. Kaplan–Meier curve showed that OSCC patients with a nuclear HIF-1α LI ≥ 60% had a significantly poorer cumulative survival than those with a nuclear HIF-1α LI < 60% (log-rank test, P  = 0.022).
Conclusions:  We conclude that the expression of HIF-1α is an early event in oral carcinogenesis. The nuclear HIF-1α LI in OSCC samples can predict the progression of OSCCs and the survival of OSCC patients.     

Serum soluble CD44v6 levels in patients with oral and maxillofacial malignancy

Objective:  To determine the levels of serum sCD44v6 in patients with oral cancer and evaluate the value of serum sCD44v6 in adjuvant diagnosis, staging and monitoring treatment response in these patients.
Materials and Methods:  A total of 112 hospitalized patients with oral and maxillofacial malignancy and 28 healthy individuals were examined for serum sCD44v6 levels. Venous blood was collected from these patients and the healthy individuals. One week after treatment, venous blood was collected once again in 60 patients with oral and maxillofacial squamous cell carcinoma (OSCC).
Results:  The sCD44v6 concentration was not significantly different between patients with oral and maxillofacial malignancy and control group ( P  > 0.05). The levels of serum sCD44v6 in patients with OSCC and salivary carcinoma showed no difference with those in control group ( P  > 0.05). The sCD44v6 level in patients with stage III and IV disease was higher than that of patients with stage I and II and that of the control group, but the difference was not significant ( P  > 0.05).  Serum sCD44v6 levels in patients with OSCC after treatment became lower than that prevailed during pretreatment ( P  < 0.05).
Conclusion:  The possible roles of CD44v6 in the diagnosis of oral and maxillofacial malignancy deserve further elucidation and evaluation. Serum sCD44v6 may be a valuable marker in monitoring treatment response in patients with OSCC.