Heat shock protein 47 expression in oral squamous cell carcinomas and upregulated by arecoline in human oral epithelial cells

J Oral Pathol Med (2010) 40 : 390–396 Background: Heat shock protein 47 (HSP47) is a product of CBP2 gene located at chromosome 11q13.5, a region frequently amplified in human cancers. Areca quid chewing is a major risk factor of oral squamous cell carcinoma (OSCC). The aim of this study was to compare HSP47 expression in normal human oral epithelium and OSCC and further to explore the potential mechanisms that may lead to induce HSP47 expression. Methods: Thirty‐two OSCC specimens and ten normal oral tissue biopsy samples without areca quid chewing were analyzed by immunohistochemistry. The oral epithelial cell line OC2 cells were challenged with arecoline, a major areca nut alkaloid, by using Western blot analysis. Furthermore, glutathione precursor N‐acetyl‐l ‐cysteine (NAC), extracellular signal‐regulated protein kinase (ERK) inhibitor PD98059, phosphatidylinositol 3‐kinase (PI3K) inhibitor LY294002, cyclooxygenase‐2 inhibitor NS‐398, and tyrosine kinase inhibitor herbimycin A were added to find the possible regulatory mechanisms. Results: HSP47 expression was significantly higher in OSCC specimens than normal epithelium (P < 0.05). No significant difference in HSP47 expression was observed with respect to age, sex, T category, stage, and differentiation (P > 0.05). The lower HSP47 expression was associated with lymph node metastasis (P = 0.015). Arecoline was found to elevate HSP47 expression in a dose‐ and time‐dependent manner (P < 0.05). The addition of NAC, PD98059, LY294002, NS398, and herbimycin A markedly inhibited the arecoline‐induced HSP47 expression (P < 0.05). Conclusion: Our findings demonstrated that HSP47 expression is significantly upregulated in areca quid chewing‐associated OSCCs. HSP47 could be used clinically as a marker for lymph node metastasis of oral carcinogenesis. In addition, arecoline‐induced HSP47 expression was downregulated by NAC, PD98059, LY294002, NS398, and herbimycin A.     

MDM2 expression in areca quid chewing-associated oral squamous cell carcinomas in Taiwan

MDM2 (murine double minute gene 2) overexpression has been implicated in the pathogenesis of human tumors via inhibition of the p53 tumor suppressor protein. To investigate the potential involvement of MDM2 overexpression in the pathogenesis of oral squamous cell carcinomas (SCCs) in Taiwan, we examined the expression of MDM2 protein and its relationship to p53 protein levels in 52 oral SCCs using antibodies to MDM2 and p53. Of the 52 patients, 36 (69 %) had tumors with positive MDM2 nuclear staining and 32 (61%) had tumors with p53 nuclear staining. Co-expression of MDM2 protein and p53 was detected in 25 (48%) cases; and 9 (17%) tumors showed neither MDM2 protein nor p53 staining. A significant correlation was observed between MDM2 protein and p53 expression in 38 cases with an areca quid (AQ) chewing habit (P=0.032). No significant correlation was found between the degree of MDM2 protein staining and the patients' ages, sex, cancer location, clinical staging, primary tumor TNM status or histological differentiation of SCC at the time of initial presentation. Kaplan-Meier analysis showed that either MDM2 protein expression or co-expression of p53 and MDM2 protein did not relate significantly to patient overall survival. Nevertheless, the high prevalence of MDM2 protein overexpression found in this study suggest that MDM2 may also participate in the carcinogenesis of AQ chewing-associated oral SCCs in Taiwan.     

Hypoxia inducible factor‐1α expression in areca quid chewing‐associated oral squamous cell carcinomas

Oral Diseases (2010) 16 , 696–701 Objectives: Hypoxia inducible factor (HIF)‐1α gene expression is mainly induced by tissue hypoxia. Overexpression of HIF‐1α has been demonstrated in a variety of cancers. The aim of this study was to compare HIF‐1α expression in normal human oral epithelium and areca quid chewing‐associated oral squamous cell carcinoma (OSCC) and further to explore the potential mechanisms that may lead to induce HIF‐1α expression. Methods: Twenty‐five OSCC from areca quid chewing‐associated OSCC and 10 normal oral tissue biopsy samples without areca quid chewing were analyzed by immunohistochemistry. The oral epithelial cell line GNM cells were challenged with arecoline, a major areca nut alkaloid, by using Western blot analysis. Furthermore, glutathione precursor N‐acetyl‐l ‐cysteine (NAC), AP‐1 inhibitor curcumin, extracellular signal‐regulated protein kinase inhibitor PD98059, and protein kinase C inhibitor staurosporine were added to find the possible regulatory mechanisms. Results: Hypoxia inducible factor‐1α expression was significantly higher in OSCC specimens than normal specimen (P < 0.05). Arecoline was found to elevate HIF‐1α expression in a dose‐ and time‐dependent manner (P < 0.05). The addition of NAC, curcumin, PD98059, and staurosporine markedly inhibited the arecoline‐induced HIF‐1α expression (P < 0.05). Conclusions: Hypoxia inducible factor‐1α expression is significantly upregulated in areca quid chewing‐associated OSCC and HIF‐1α expression induced by arecoline is downregulated by NAC, curcumin, PD98059, and staurosporine.     

舌鳞癌细胞热处理后HSP27的表达变化

目的 观察热疗后舌鳞癌Tscca细胞中热休克蛋白27 (heat shock protein 27,HSP27)的变化及其对凋亡的作用.方法 常规培养的Tscca细胞分6组,对照组不加热,其余5组43℃水浴法热处理40 min后分别常规培养2、4、8、12、24h,应用蛋白组学方法检测HSP27变化.运用空载质粒(pcDNA3)、pcDNA3-HSP27质粒转染Tscca细胞24h,免疫印迹分析靶细胞中的HSP27表达.43℃水浴处理未转染及转染组细胞0 min、40 min,再培养24 h后流式细胞仪检测细胞凋亡率.结果 加热后12 h内细胞内HSP27持续升高.HSP27质粒转染细胞中HSP27蛋白表达增强.0 min热处理,未转染组、pcDNA3转染组及HSP27质粒转染组细胞凋亡率无差异;40min热处理,未转染组与pcDNA3转染组凋亡率无差异,HSP27质粒转染组分别与未转染组及空载质粒转染组比较,均有差异(P＜0.05).结论 热处理后舌鳞癌Tscca细胞中HSP27含量升高.HSP27的变化与Tscca细胞凋亡的变化有关.     

Infrequent p53 mutations in patients with areca quid chewing-associated oral squamous cell carcinomas in Taiwan

Mutations in the conserved regions (exons 5-9) of the p53 gene were investigated in 37 untreated human primary oral squamous cell carcinomas (SCCs) using polymerase chain reaction-single strand conformation polymorphism and DNA sequencing analyses. P53 mutations were detected in 2 of 37 (5.4%) oral SCC cases. One tumor sample (case 23) showed a mis-sense point mutation at codon 177, changing CCC to CTC, which resulted in a substitution of proline to leucine in the p53 protein. The other tumor (case 33) had a point mutation at codon 266, changing GGA to AGA and causing a substitution of glycine to arginine in the p53 protein. These two patients with p53 mutations did not have an areca quid chewing habit. These results suggest that mutations in the p53 gene may not play a role in the pathogenesis of human oral SCCs in Taiwan. Recently, we have shown that positive p53 staining was observed in 47 of 81 (58%) cases of oral SCC. The discrepancies between positive p53 protein staining and the low prevalence of p53 mutation in oral SCCs indicate that other mechanism(s) are involved in p53 overexpression.     

Skp2蛋白在口腔鳞癌中的表达及其与c-myc、p27蛋白表达的关系

目的:研究Skp2、c-myc及p27蛋白在口腔鳞癌组织中的表达.方法:免疫组化检测Skp2、c-myc及p27蛋白在54例口腔鳞癌和15例正常口腔黏膜组织中的表达.结果:口腔鳞癌组织中Skp2、c-myc阳性表达率分别为35.19%(19/54)和38.89%(21/54),显著高于正常口腔黏膜组织6.67%(1/15)、6.67%(1/15)(P＜0.05);p27阳性表达率为55.56%(30/54)显著低于正常口腔黏膜组织86.67%(13/15)(P＜0.05);Skp2的表达与口腔鳞癌的临床分期、病理分级、淋巴结转移显著相关(P＜0.05),与年龄、性别、肿瘤部位等因素无关(P＞0.05);口腔鳞癌中Skp2与c-myc表达呈正相关(r=0.562,P＜0.01);与p27蛋白的表达呈负相关(r=-0.532,P＜0.01).结论:Skp2蛋白过表达在口腔鳞癌的发生及发展中起重要作用;并可能与c-myc蛋白有协同作用,Skp2蛋白过表达与靶蛋白p27蛋白降解有关,联合检测Skp2、c-myc及p27蛋白的表达有助于综合评估口腔鳞癌的生物学行为.     

Mutations of the adenomatous polyposis coli gene in areca quid and tobacco-associated oral squamous cell carcinomas in Taiwan.

BACKGROUND: Adenomatous polyposis coli (APC) gene mutations have been demonstrated not only in colorectal tumors but also in a variety of human cancers. METHODS: To elucidate the possible roles of APC gene mutations in oral squamous cell carcinomas (OSCCs), we examined 40 untreated human primary OSCCs using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and DNA sequencing assays. RESULTS: By screening nearly one-half of the coding region (codons 279-1673, including the MCR) of the APC gene, five missense mutations and a 1-base pair deletion were detected in five (12.5%) tumors, resulting in five amino-acid substitutions or a truncation of the APC protein. All patients with APC mutations were both areca quid chewers and tobacco smokers (P = 0.049). CONCLUSIONS: These results suggest that APC mutations may also contribute to the carcinogenesis of at least some OSCCs in Taiwan, especially for the users of areca quid and tobacco.     

Heat shock protein expression in oral lichen planus

To assess the potential role of heat shock protein (HSP) in the pathogenesis of oral lichen planus (OLP), sections of OLP, normal oral mucosa, non-specific oral ulceration (NSOU) and dysplastic OLP were assessed for HSP expression using avidin-biotin complex immunohistochemistry with an anti-HSP 70 polyclonal antibody. There were statistically significant differences in both the vertical and horizontal staining distribution when other groups were compared with the OLP group (p<0.01). Using microdensitometry, the mean staining intensity in OLP, dysplastic OLP and NSOU was elevated in comparison with normal oral mucosa (p<0.001). In a standard tritiated thymidine uptake assay, lymphocytes extracted from nine OLP lesions demonstrated significant proliferation when stimulated with purified protein derivative (PPD), of which HSP is a major constituent, with stimulation indices ranging from 2 to 132. These results are consistent with the hypothesis that, in OLP patients, diverse exogenous agenst may cause upregulated expression of HSP by oral mucosal keratinocytes. A reaction of cytotoxic T lymphocytes to these activated keratinocytes may then result in the tissue destruction which is characteristic of OLP lesions.     

口腔鳞状细胞癌中p27表达及其临床意义

目的 分析口腔鳞状细胞癌p27的表达与临床病理资料及预后的关系。方法 回顾性研究50例口腔鳞状细胞癌及10例正常口腔粘膜p27的表达情况，采用SABC法根据染色指标记数，并利用Cox比例风险模型进行生存多因素分析。结果 p27在所有正常口腔粘膜上皮均呈现高表达，而在口腔鳞状细胞癌组织有30例(60％)至p27表达降低，p27低表达与口腔鳞状细胞癌的临床分期晚、易发生淋巴结转移以及预后差，生存期短显著相关，p27高表达则相反。多因素Cox回归分析表明p27的表达可作为口腔鳞癌辅助性的预后指标。结论 p27的表达与口腔鳞癌的发生发展有密切关系，并与肿瘤的预后密切相关，可作为辅助性的预后指标。     

Alteration of integrin expression in oral squamous cell carcinomas

OBJECTIVE: This study examines the intensity of expression of beta 1, alpha 2, alpha 3, alpha 5, alpha 6 integrin subunits in oral squamous cell carcinoma (SCC) as opposed to normal oral epithelium, and the intensity of expression and distribution pattern of the above subunits in relation to tumour differentiation grade. MATERIALS AND METHODS: Cryostat sections of 25 cases of oral SCC and 15 cases of normal oral epithelium were studied by immunohistochemistry (APAAP method). RESULTS: The intensity of expression of beta 1, alpha 2 (Pearson chi 2 P < 0.001) and alpha 6 (Test for Trend P < 0.05) integrin subunits was reduced significantly in SCC compared to normal oral epithelium. All integrin subunits were mainly expressed in the peripheral cell layer of tumour islands. No correlation was found between the intensity of integrin expression and the degree of differentiation in SCC. The same applied to the distribution pattern of the integrin subunits. By means of cross examination of all integrins, the loss of intensity of alpha 2 beta 1 integrin expression was found to have the strongest correlation with oral SCC (Ordered Logistic Regression). CONCLUSIONS: Reduced intensity of expression of all subunits was found in oral SCC compared to normal epithelium. Further investigation is needed to determine whether alpha 2 beta 1 integrin expression can be used as a prognostic evaluator for the behaviour of the disease.     

p27及p16蛋白在口腔鳞癌中的表达和意义

目的 探讨p27与p16基因产物在口腔鳞癌和癌旁组织中的表达，了解p27与p16在口腔鳞癌发生中的意义。方法 采用p27与p16单克隆抗体，用免疫组化S—P法对37例口腔鳞癌组织、30例癌旁组织、10例正常口腔黏膜p27与p16的表达进行检测，结果 p27与p16表达减少与口腔鳞癌的发生和恶性程度有关。p27表达下降与临床分期有关，p16与临床分期无关。p27与p16在口腔鳞癌中表达无关，但在口腔鳞癌中表达随恶性程度的增高而降低。结论 p27与p16蛋白有可能作为有价值的标志物，在口腔鳞癌的诊断、治疗、预后判断中起辅助作用。     

Prognostic role of p21WAF1 expression in areca quid chewing and smoking-associated oral squamous cell carcinoma in Taiwan.

BACKGROUND: Alterations in p21WAF1 protein expression have been observed in a wide variety of human cancers by immunohistochemistry, and both decreased and increased levels of p21WAF1 protein expression have been shown to correlate with poor prognosis. METHOD: To examine the relation between p21WAF1 protein expression and prognosis in oral squamous cell carcinomas (SCCs), we performed an immunohistochemical study with antip21WAF1 antibody on 43 oral SCCs. Immunostaining results were then correlated with p53 protein levels, clinicopathological parameters of the tumors and overall patient survival. RESULTS: Of the 43 patients, 31 (72%) had tumors with positive p21WAF1 nuclear staining and 27 (63%) had tumors with p53 nuclear staining. There was no significant correlation between p21WAF1 and p53 protein expressions and both mutant p53-containing oral SCCs overexpressed p21WAF1 protein. In addition, no significant correlation was found between the p21WAF1 expression and the patients' age, sex, oral habit, cancer location, or primary tumor TNM status at the time of initial presentation. The Kaplan-Meier analysis showed a significant correlation between p21WAF1 protein overexpression and poor patient overall survival (P = 0.049). When p53 and p21WAF1 were evaluated together, the 5-year overall survival was lowest in p53(+)-p21WAF1(+) patients and highest in p53(-)-p21WAF1(-) patients (P = 0.057). CONCLUSION: Combined evaluation of p21WAF1 and p53 expressions may be useful in estimating the prognosis of patients with oral SCCs in Taiwan.     

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.     

Expression of p53 protein correlates with decreased survival in patients with areca quid chewing and smoking-associated oral squamous cell carcinomas in Taiwan

Expression of p53 protein was examined in oral squamous cell carcinoma (SCC) from patients who were areca quid (AQ) chewers and/or tobacco smokers, using anti-p53 antibodies with an immunoperoxidase technique. Positive p53 stain was observed in 47 of 81 (58%) cases of oral SCC. p53 overexpression was found to higher in patients without AQ chewing and smoking habits than in patients with these two habits (80% vs 52%, P=0.076). No significant correlation was found between p53 expression and the patients' age, sex, cancer location, clinical staging, primary tumor TNM status, or histological differentiation of SCC. The Kaplan-Meier analysis showed that the prognosis for patients with p53-negative tumors was significantly better than that for patients with p53-positive tumors (P<0.05). A significant correlation was also observed between positive lymph node status and poor prognosis (P<0.05). These results suggest that p53 may serve as an adjuvant marker of poor survival in patients with oral SCCs in Taiwan.     

Eotaxin expression in oral squamous cell carcinomas with and without tumour associated tissue eosinophilia

AIM: Eotaxin is a powerful and selective eosinophil chemoattractant. The purpose of this study was to compare the expression of eotaxin in oral squamous cell carcinomas with and without tumour associated tissue eosinophilia (TATE). The mechanisms that control the recruitment of eosinophils to these tumours are not clearly established. METHODS: A total of 60 patients with oral squamous cell carcinomas (OSCC) with TNM stages II and III, located in the tongue, oral floor, retromolar area and inferior gingiva were divided in two groups: 1--OSCC with intense eosinophilic inflammatory infiltrate and 2--OSCC with absent/low eosinophilic inflammatory infiltrate. The eotaxin expression was analyzed by immunohistochemistry using standard streptavidin-biotin-peroxidase complex technique with monoclonal (mouse anti-human eotaxin) and polyclonal (rabbit anti-human eotaxin) antibodies. RESULTS: The eotaxin expression was identified in normal oral mucosa as well as in both OSCC groups including malignant epithelial cells, eosinophils, neutrophils, plasma cells and fibroblasts. The eosinophils showed intense immunopositivity for eotaxin. CONCLUSION: These results suggest that the eotaxin expressed in oral squamous cell carcinomas, mainly derived from eosinophils, is probably involved in the mechanisms of eosinophils chemotaxis to the tumour and in the maintenance of TATE in these malignant tumours.     

沉默热休克蛋白27基因对头颈部鳞状细胞癌细胞生物学行为的影响

目的 观察长效沉默热休克蛋白（Hsp）27基因后头颈部鳞状细胞癌细胞生物学行为的改变。方法 实验分为3组：高滴度pLenti-shRNA-Hsp27慢病毒颗粒长效转染入UM-SCC-22B细胞为实验组（shHsp27组）,常规培养UM-SCC-22B细胞（ctrl组）为空白对照,UM-SCC-22B细胞转染pLenti-shRNA-ctrl慢病毒颗粒（shctrl组）为阴性对照。采用实时荧光定量聚合酶链反应和蛋白质印迹法检测各组中Hsp27的表达,采用MTS细胞增殖实验、细胞划痕实验及Matrigel侵袭实验,观察各组Hsp27表达抑制后UM-SCC-22B细胞的增殖、迁移和侵袭能力的变化。结果 shHsp27组的Hsp27表达明显降低;MTS细胞增殖实验可见,细胞培养24、48 h后,shHsp27组的细胞增殖能力与ctrl组和shctrl组无明显差异;划痕实验表明,划痕产生72 h后,ctrl组细胞迁移能力为shHsp27组的4.38倍;Matrigel侵袭实验显示,ctrl组细胞的体外侵袭能力为shHsp27组的2.03倍。结论 长效转染慢病毒颗粒pLenti-shRNA-Hsp27能够高效、特异地沉默高转移潜能头颈部鳞状细胞癌细胞系UM-SCC-22B的Hsp27基因表达,并能显著抑制其体外侵袭和转移能力。