Cancer stem cell immunophenotypes in oral squamous cell carcinoma

J Oral Pathol Med (2011) 40 : 135–142 Background: The presence of cancer stem cell (CSC) antigens can be evidenced in some human tumors by phenotypic analysis through immunostaining. This study aims to identify a putative CSC immunophenotype in oral squamous cell carcinoma (OSCC) and determine its influence on prognosis. Methods: The following data were retrieved from 157 patents: age, gender, primary anatomic site, smoking and alcohol intake, recurrence, metastases, histologic classification, treatment, disease‐free survival (DFS), and overall survival (OS). An immunohistochemical study for CD44 and CD24 was performed in a tissue microarray of 157 paraffin blocks of OSCCs. Results: In univariate analysis, the immunostaining pattern showed significant influences in relation to OS for alcohol intake and treatment, as well as for the CD44⁺ and CD44^?/CD24^? immunophenotypes. The multivariate test confirmed these associations. Conclusions: Based on our results, the CD44 immunostaining and the absence of immunoexpression of these two investigated markers can be used in combination with other clinicopathologic information to improve the assessment of prognosis in OSCC.     

Myeloid-derived suppressor cells and plasmacytoid dendritic cells are associated with oncogenesis of oral squamous cell carcinoma

Myeloid-derived suppressor cells (MDSCs) help establish the tumor microenvironment by suppressing T-cell response in tumor-bearing hosts. Plasmacytoid dendritic cells (pDCs) activate antigen-specific T cells, thereby, maximizing their antitumor effects. IDO1 is associated with both MDSCs and pDCs and plays a major role in the formation of the tumor-mediated immunosuppressive environment. We utilized immunohistochemistry to examine the involvement of IDO1 in oral squamous cell carcinoma (OSCC) and oral potentially malignant disorders (OPMDs, precancerous lesions). We examined the expression of MDSC markers, CD11b and CD33, as well as pDC markers, CD303 and IDO1, in 60 OSCC and 45 precancerous lesion specimens and analyzed their association with clinicopathological parameters. Expression of these biomarkers identifying MDSCs and pDCs was high in precancerous lesions in patients with severe dysplasia and OSCC. While detecting pDCs, high CD303 and IDO1 expression levels were frequently observed in moderately or poorly differentiated OSCCs. CD11b, CD33, and CD303 levels were significantly correlated with the mode of invasion; CD33 was correlated with OSCC invasion depth while the other three markers tended to be highly expressed in superficial cancer cases showing microinvasion. Expression levels of all four biomarkers were significantly associated with the cancerization of OPMDs to OSCCs. We show, for the first time, that the infiltration of MDSCs and pDCs is significantly associated with progression of premalignant lesions to OSCC. This suggests that these cells may act as prognostic biomarkers for premalignant lesion progression and that immunotherapeutic approaches that control each of these immunosuppressive cells may protect against progression to malignancy.     

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目的    观察综合序列治疗口腔鳞癌临床疗效,探索治疗口腔鳞癌合理治疗方案。方法    对2000年8月至2005年8月在枣庄矿业集团中心医院及山东大学口腔医院确诊并住院的口腔鳞癌中晚期患者60例,经过采用平阳霉素新辅助化疗、手术、术后放疗等手段进行规范的综合序列治疗,观察5年存活率及复发转移情况。结果        60例患者1年后复发率20.0％,2年后复发率23.3％,5年后复发率30.0％,5年存活率75.0％。结论    规范合理的综合序列治疗方法是治疗口腔鳞癌比较有效的手段,能明显提高口腔癌患者的存活率。     

Stem cell patterns in cell lines derived from head and neck squamous cell carcinoma

The initiation, growth, recurrence and metastasis of solid tumours, including squamous cell carcinoma of the head and neck region, have been related to the behaviour of a small subpopulation of 'tumour-initiating' cells. Cells with stem cell characteristics have also been identified in cell lines derived from cancers and the aim of the present work was to extend examination of such cells. Established cell lines were examined for their patterns of colony morphologies and staining, the presence of a Hoechst dye-excluding 'side population', expression of the putative stem cell markers CD44, CD133 and CD29, and their ability to grow as 'cancer spheroids'. Two cell lines, CaLH2 and CaLH3, recently generated from HNSCC tumour biopsies, were similarly examined. All cell lines showed a holoclone/meroclone/paraclone series of colony morphologies and cell sorting indicated that CD44 marker expression was related to clonogenicity. FACS analysis after exposure to Hoechst dye indicated that the CA1, H357 and UK1 cell lines contain a dye-excluding 'side population', a property associated with stem-like subpopulations. When held in suspension, all cell lines formed spheroids that could be re-passaged. These observations indicate that cell lines derived from HNSCC contain cells with stem cell properties and that such cell lines may provide experimental systems relevant to the behaviour of stem cells present in the tumours of origin and to their responses to therapy.     

The role of cyclin‐dependent kinases in oral potentially malignant disorders and oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a major global health problem with a relatively low‐moderate 5‐year survival rate. OSCC is often preceded by lesions and conditions known as oral potentially malignant disorders (OPMDs) that have an increased risk of malignant transformation. Despite advances in diagnostic technology and cancer research, the prognosis of OSCC remains poor as it is frequently detected a late stage. Understanding the molecular pathways involved in oral carcinogenesis provides a platform to identify biomarkers that may allow the early detection of OSCC and accurate prediction of the malignant potential of OPMDs. In addition, specific molecular inhibitors can be developed to target these important pathways and allow advanced therapeutic management to improve the prognosis of this malignancy. A common feature across a number of different cancers is the dysfunction of cell cycle moderator proteins known as cyclin‐dependent kinases. This review summarises the current literature regarding the role of cyclin‐dependent kinases in oral carcinogenesis with a particular focus on cyclin‐dependent kinases 4 (CDK4) and 6 (CDK6). This is of particular relevance as CDK4 and CDK6 inhibitors have shown some promising results in other cancer types and are interesting potential treatments for OSCC.     

Histone modifications in oral squamous cell carcinoma and oral potentially malignant disorders

Oral squamous cell carcinoma (OSCC) is a common malignancy with dismal prognosis without effective therapeutic options in advanced cases. The evolution from oral potentially malignant disorders to OSCC has poorly described underlying epigenetic features. With the ability of silencing or activation of vital genes, histone modifications’ and modifiers’ potentiality for early diagnosis, prognosis predicting, and therapy in OSCC were evaluated by extensive epigenetic studies. This review investigates the roles of dysregulated histone modifications and the associated modifying enzymes in OSCC onset and progression. Also, we focus on the current advances of histone modifications as therapeutic targets and the potential value of epi‐drugs.     

Midkine expression in oral squamous cell carcinoma and leukoplakia

J Oral Pathol Med (2012) 41 : 21–26 Background: Midkine (MK), a 13‐kDa heparin‐binding growth factor, is overexpressed in various human cancers. However, its role in the development and progression of oral cavity squamous cell carcinoma (OCSCC) is still unclear. Thus, the aim of this study was to evaluate the expression of MK in samples of OCSCC, leukoplakia, and healthy oral mucosa (control). Methods: Surgically excised specimens from patients with primary OCSCC (n = 28) were immunostained for MK, Ki‐67, PCNA, p53, bcl‐2, Bax, and CD31. Besides this, MK expression was also investigated in leukoplakia and normal oral mucosa. The relationship of MK⁺ cells with clinical parameters (tumor location, tumor size, lymph node metastasis, and survival) and microscopic parameters (WHO histological grading, intensity of inflammation, proliferation index, apoptosis, and angiogenesis) was also evaluated. Results: The results showed that MK expression was increased in OCSCC in relation to leukoplakia and normal mucosa. Furthermore, MK expression was increased in late‐stage tumors (T3/T4) compared with early‐stage lesions (T1/T2). MK‐positive lesions also showed increased expression of the anti‐apoptotic protein bcl‐2. Conclusion: OCSCC, particularly late‐stage tumors, exhibits increased MK expression, which may be involved in tumor progression via upregulation of anti‐apoptotic genes, as shown by the augmented bcl‐2 positivity in MK‐positive tumors.     

循环肿瘤细胞与口腔鳞状细胞癌相关性的研究进展

循环肿瘤细胞(CTCs)是从原发灶部位脱落、释放并转移到血液循环的肿瘤细胞,目前广泛应用于肺癌、乳腺癌等恶性肿瘤的早期诊断、治疗、疗效评价和预后判断,但是在口腔鳞状细胞癌(OSCC)中运用较少且缺乏相关的临床证据.有研究表明,CTCs是OSCC相对独立的预后指标,而且是复发或转移的重要原因之一.本文为深入阐述OSCC中...     

Possible involvement of stem cell factor and endothelin-1 in the emergence of pigmented squamous cell carcinoma in oral mucosa

We present here the clinical, morphological and immunohistochemical features of a pigmented squamous cell carcinoma (SCC) in the oral mucosa of the hard palate of a 76-year-old Japanese man. He underwent a partial resection of the maxilla subsequent to radiotherapy. The tumor was typical, moderately well-differentiated SCC but had many melanocytes (melanocytosis) within it. Immunohistochemical analysis for stem cell factor (SCF) and endothelin-1, both of which are known to stimulate proliferation and differentiation of melanocytes, revealed prominent expression of both factors in the neoplastic squamous cells of the pigmented SCC, while the non-pigmented oral SCC showed little sign of either factor. These findings strongly suggest that SCF and endothelin-1 secreted by neoplasmic squamous cells are involved in the emergence of a rare variant of oral SCC.     

舌鳞状细胞癌中肿瘤干细胞对放疗敏感性体外研究

目的：探讨舌鳞状细胞癌中肿瘤干细胞对放疗的敏感性。方法：采用磁珠分选技术、细胞免疫荧光染色和细胞增殖活性试验等方法,研究经分选后得到的肿瘤干细胞和阴性细胞在放疗后细胞增殖活性方面的差异。结果：细胞免疫荧光结果显示,CD133和 CD44在分选出来的 CD133＋/CD44＋细胞高表达,而在 CD133-/CD44-细胞基本不表达。CCK8实验结果显示,分选出来的 CD133＋/CD44＋细胞较 CD133-/CD44-细胞在放疗的作用下具有更高的细胞相对增殖率。结论：经磁珠分选出来的舌癌肿瘤干细胞（CD133＋/CD44＋细胞）更能耐受放疗的作用。     

Markedly increased Oct4 and Nanog expression correlates with cisplatin resistance in oral squamous cell carcinoma

J Oral Pathol Med (2011) 40 : 621–628 Background: Oral squamous cell carcinoma (OSCC) is the sixth most prevalent cancer worldwide. Cancer stem cells (CSC) model theoretically contribute to tumor growth, metastasis, and chemo‐radioresistance. Cisplatin is a widely used chemotherapeutic agent for OSCC treatment. The aim of this study was to compare stemness genes expression in chemo‐sensitive and chemo‐resistant specimens and further explore the potential markers that may lead to induce chemo‐resistance in OSCC. Methods: The study method is the treatment of OC2 cells with cisplatin select cisplatin‐resistant OC2 cells. Self‐renewal ability was evaluated by cultivating parental and cisplatin‐resistant OC2 cells within sphere‐forming assay after serial passages. Differential expression profile of stemness markers between parental and cisplatin‐resistant OC2 cells was elucidated. The parental and cisplatin‐resistant OC2 cells were assessed for migration/invasion/clonogenicity tumorigenic properties in vitro. Expression of stemness markers in chemo‐sensitive and chemo‐resistant patients with OSCC was performed by immunohistochemistry staining in vivo. Results: Sphere‐forming/self‐renewal capability was increased in cisplatin‐resistant OC2 cells. Cisplatin‐resistant OC2 cells highly expressed the stemness markers (Nanog, Oct4, Bmi1, CD117, CD133, and ABCG2). Furthermore, cisplatin‐resistant OC2 cells increased migration/invasion/clonogenicity ability. Notably, up‐regulation of Oct4 and Nanog expression was significantly observed in cisplatin‐resistant patients with OSCC (**P < 0.01). Conclusions: These data indicate that cancer stem‐like properties were expanded during the acquisition of cisplatin resistance in OSCC. Clinically, oral cancer stemness markers (Oct4 and Nanog) overexpression may promote the OSCC’s recurrence to resist cisplatin.