An immunohistochemical study of XIAP expression in pleomorphic adenoma and carcinoma ex pleomorphic adenoma

Background: X‐linked inhibitor of apoptosis protein (XIAP) is a member of the inhibitor of apoptosis proteins family of caspase inhibitors. Expression of XIAP in various neoplasms has been associated with aggressive behavior. The biological progression from pleomorphic adenoma (PA) to carcinoma ex pleomorphic adenoma (CXPA) has been poorly understood. We studied XIAP expression by immunohistochemistry in PA and CXPA. Materials and methods: Formalin‐fixed, paraffin‐embedded representative sections of 14 cases of PA and seven cases of CXPA (four invasive and three intracapsular) were stained with anti‐XIAP (# 610763; BD Biosciences, San Jose, CA, USA) following citrate‐based antigen retrieval. Granular cytoplasmic staining was considered positive and intensity was assessed from weak (1+) to strong (3+). PAs were morphologically evaluated for cellularity, cytological atypia and mitotic activity. Results: Of the seven PAs composed mostly of myxohyaline stroma with scattered ductal elements, two tumors showed no staining and five showed rare (<1%) 1+ positive cells. Of seven more cellular PAs, five had sheets of tumor cells comprising more than 50% of the tumor and two had sheets comprising more than 80% of the tumor (cellular PA), focal to diffuse 2+ to 3+ staining was observed. Tumor cells with strong staining often exhibited cytological atypia in the form of nuclear enlargement and contour irregularity, prominent nucleoli and eosinophilic cytoplasm. Mitotic activity was occasionally seen in cellular areas expressing XIAP. All cases of CXPA demonstrated diffuse 3+ staining in the carcinomatous component and 1+ to focally 3+ staining in cellular areas of the underlying PA. Conclusion: Increased expression of XIAP from PA to cellular PA to CXPA and in atypical cells within cellular areas of PA adds to our growing understanding of defective apoptotic pathways in malignant transformation in this group of salivary gland tumors and suggests an adenoma to adenocarcinoma model of progression. Further correlation with other oncogene expression may provide insight into the multiple molecular pathways that are affected in these tumors. Targeted therapy of XIAP may play a future role in the management of CXPA.     

唾液腺恶性多形性腺瘤HER2基因扩增与临床病理特征及预后的关系

目的: 检测唾液腺恶性多形性腺瘤（malignant pleomorphic adenoma,MPA）中人上皮生长因子受体2（human epithelial growth factor receptor 2,HER2）蛋白表达、基因扩增情况,分析其与肿瘤临床病理及患者预后的相关性,以期评估其作为靶向治疗位点的可能性。方法: 应用免疫组织化学染色法检测140例MPA患者肿瘤组织中HER2蛋白的表达,对HER2基因扩增情况不明确者（HER2 2+）行荧光原位杂交,确定基因扩增状态。统计140例患者临床病理资料并进行随访,应用SPSS16.0软件包中的Kaplan-Meier、Cox比例风险模型,分析HER2基因扩增与MPA肿瘤临床病理及患者预后的相关性。结果: 140例MPA患者中,HER2阳性率为25%。腺癌亚型MPA中,HER2阳性率达到40.5%（32/79）,显著高于肌上皮癌亚型MPA（4.9%,3/61）（P<0.05）。HER2阳性与肿瘤患者性别、组织学分级及N分期显著相关。生存分析显示,HER2阳性患者总生存率及疾病别生存率低。结论: HER2基因过表达及扩增与MPA肿瘤细胞恶变亚型显著相关,并且提示MPA患者较差的预后状态。     

Role of CD44 in tumor‐initiating cells of salivary gland pleomorphic adenoma: More than a surface biomarker

CD44, a cell‐surface glycoprotein, functions as a receptor for hyaluronic acid. Our research group has previously shown that CD44 is a biomarker for the CD44^hi cells (tumor‐initiating cells; TICs) in murine salivary gland tumors. However, little is known concerning the biological roles of CD44 in the tumorigenesis of pleomorphic adenoma. The present study is aimed to investigate the effects of CD44 on the proliferation, invasive capability, and apoptosis of TICs in vitro, as well as the tumorigenicity of TICs in vivo. The results demonstrated that knockdown of CD44 attenuated the malignant phenotype of TICs. Furthermore, in vivo xenograft studies indicated that CD44 knockdown inhibited tumorigenesis of pleomorphic adenoma. In addition, neither the CD44^low cells nor the CD44‐modified CD44^low cells developed neo‐tumors, which indicated that overexpression of CD44 did not enable the CD44^low cells to be transformed into TICs. Taken together, these data demonstrate that CD44 not only acts as a biomarker, but also functions as a key player in the tumor‐initiating capacity of TICs. These results shed light on the pathogenesis of salivary gland tumors and provide a potential therapeutic target for treating pleomorphic adenoma.     

HER2/neu expression in adenoid cystic carcinoma of salivary gland origin: an immunohistochemical study

BACKGROUND: Adenoid cystic carcinoma (ACC) is a malignant tumor of salivary gland origin, which is characterized by a high rate of local recurrence and distant hematogenous metastasis. Despite aggressive surgical treatment and radiotherapy, the patient's long-term prognosis is dismal. Prompted by recent studies on the amplification of the oncogene HER2/neu in salivary gland tumors, we analyzed the immunohistochemical overexpression of HER2/neu in salivary glands ACC. If the tumor exhibits overexpression of HER2/neu, then treating it with the anti-HER2/neu therapeutic agent, Herceptin (Trastuzumab, Genentech, CA), could be considered. METHODS: The study comprised of 32 samples of formalin-fixed, paraffin-embedded specimens. All laboratory procedures and scoring criteria were performed according to currently approved FDA methods. RESULTS: HER2/neu overexpression was found in only five (16%) cases. Four cases (13%) scored 1+ and one case (3%) scored 2+. CONCLUSIONS: The low prevalence of HER2/neu overexpression in ACC limits the clinical utility of Herceptin therapy for salivary gland ACC.     

Co‐expression of Hif1α and CAIX is associated with poor prognosis in oral squamous cell carcinoma patients

J Oral Pathol Med (2010) 39 : 313–317 Background: This study investigates the prognostic impact of the expression of hypoxia‐inducible factor 1α (Hif1α) and carbonic anhydrase IX (CAIX) detected by immunohistochemistry in oral squamous cell carcinoma (OSCC). Methods: Statistical analysis of immunohistochemical results with clinical parameters including survival outcomes was performed for 80 OSCC patients. Results: Patients with a low expression of both proteins survived on average 54.8 months, whereas those with an increased expression of Hif1α in their tumors combined with a low expression of CAIX survived on average only 37.6 months (P = 0.026). In multivariate Cox’s regression hazard analysis, again patients with a low expression of Hif1α/CAIX had the best prognosis, whereas patients with increased Hif1α and low CAIX expression carried a 4.97‐fold increased risk of tumor‐related death (P = 0.042). Conclusion: A co‐detection of low Hif1α/CAIX expression is significantly correlated with a better prognosis for OSCC patients, which may have implications for therapy options for these patients.     

A study of phosphorylated ERK1/2 and COX‐2 in early stage (T1–T2) oral squamous cell carcinomas

Background: Histomorphological grading at the invasive front of oral squamous cell carcinomas (OSCCs) may provide useful prognostic information. In the present study, we investigated the presence and prognostic value of activated phosphorylated extracellular signal‐regulated kinases 1 and 2 (p‐ERK1/2) and cyclo‐oxygenase‐2 (COX‐2) both at the invasive front and in central/superficial parts of OSCCs. Methods: Using immunohistochemistry, we assessed the presence of p‐ERK1/2 and COX‐2 in 53 early stage OSCCs. Clinical data were recorded prospectively. The end point was disease‐free survival. Results: p‐ERK1/2 staining was present in almost all tumours. The staining was mostly nuclear in the cells of the invasive front and either nuclear or nuclear/cytoplasmic in central/superficial tumour parts. COX‐2 was observed in almost all tumours (98%) and the staining was often restricted to focal areas. Most tumours were COX‐2 negative at the invasive front. The lowest P‐value in survival analyses was P = 0.06 for p‐ERK1/2 at the invasive front. COX‐2, the histomorphological grading systems and TNM stage were of no prognostic value. Conclusion: p‐ERK1/2 was present in almost all tumours and p‐ERK1/2 may be a prognostic marker at the invasive front of OSCCs. In early stage OSCCs, most tumours did not express COX‐2 at the invasive front.     

Expression of CD163, interleukin‐10, and interferon‐gamma in oral squamous cell carcinoma: mutual relationships and prognostic implications

Tumor‐associated macrophages (TAMs) and their associated inflammatory cytokines represent the major inflammatory component of the stroma of many tumors and can affect prognosis in the case of neoplasms. The objective of this study was to determine the prognostic significance of CD163⁺ cells, interleukin‐10 (IL‐10), and interferon‐gamma (IFN‐γ) in oral lesions associated with oral squamous cell carcinoma (OSCC). The levels of CD163, IFN‐γ, and IL‐10 in the tissue samples of 240 patients with OSCC and 58 patients with other oral lesions were assessed by immunohistochemistry. Individuals with low IFN‐γ levels, high IL‐10 levels, and low CD163 levels were of special concern with respect to OSCC progression. We found that high levels of CD163, or a combination of low IFN‐γ levels, high IL‐10 levels, and low CD163 levels, were associated with poorer overall survival (OS). CD163⁺ cells provide better predictive power for OS in comparison with traditional markers, such as clinical stage and lymph node metastasis. Therefore, CD163⁺ cells may be effective prognostic predictors of OSCC. IL‐10 may also indicate poor outcomes when IFN‐γ secretion is low and the cells are CD163^?.