An update of knowledge on cortactin as a metastatic driver and potential therapeutic target in oral squamous cell carcinoma

Cortactin is a protein encoded by the CTTN gene, localized on chromosome band 11q13. As a result of the amplification of this band, an important event in oral carcinogenesis, CTTN is also usually amplified, promoting the frequent overexpression of cortactin. Cortactin enhances cell migration in oral cancer, playing a key role in the regulation of filamentous actin and of protrusive structures (invadopodia and lamellipodia) on the cell membrane that are necessary for the acquisition of a migratory phenotype. We also analyze a series of emerging functions that cortactin may exert in oral cancer (cell proliferation, angiogenesis, regulation of exosomes, and interactions with the tumor microenvironment). We review its molecular structure, its most important interactions (with Src, Arp2/3 complex, and SH3‐binding partners), the regulation of its functions, and its specific oncogenic role in oral cancer. We explore the mechanisms of its overexpression in cancer, mainly related to genetic amplification. We analyze the prognostic implications of the oncogenic activation of cortactin in potentially malignant disorders and in head and neck cancer, where it appears to be relevant in the development of lymph node metastasis. Finally, we discuss its usefulness as a therapeutic target and suggest future research lines.     

Significance of myofibroblasts in oral squamous cell carcinoma

J Oral Pathol Med (2011) 40 : 201–207 It is now recognized that the tumor microenvironment makes significant contribution to tumor progression. Activated fibroblast endothelial cells, inflammatory cells, and various extra cellular matrix components are parts of this microenvironment. Most of the activated fibroblasts are α‐smooth muscle actin–positive myofibroblast that often represent the majority of tumor stromal cells. Their production of growth factors chemokines and extracellular matrix facilitates tumor growth. Myofibroblast have been demonstrated in close to 50% of oral squamous cell carcinomas. In this review, we highlight the histological distribution of myofibroblast in oral squamous cell and the myofibroblast relation to tumor growth on prognosis.     

口腔疣状癌与口腔鳞癌中PTTG1 mRNA表达的对比研究

目的：研究垂体肿瘤转化基因-1（Pituitary tumor transforming gene 1,PTTG1）在口腔疣状癌中的表达,并与口腔鳞癌（OSCC）作比较,探讨其在口腔疣状癌及OSCC中发生发展中的作用。方法采用逆转录多聚酶链反应（RT-PCR）技术分别检测口腔疣状癌和OSCC中PTTG1 mRNA相对含量,并取自身的癌旁黏膜和正常口腔黏膜作比较。结果：PTTG1在疣状癌和无淋巴结转移的高分化SCC的癌组织、正常黏膜和癌旁黏膜中均有不同程度的表达,但这种表达无显著差异（P〉0.05）;在有淋巴结转移的高分化SCC中,PTTG1的表达在癌组织和癌旁黏膜比正常黏膜有增高的趋势,中分化SCC中这种增高趋势更为明显,但统计学上均无显著意义（P〉0.05）。PTTG1在口腔疣状癌、无淋巴结转移的高分化SCC、有淋巴结转移的高分化SCC及中分化SCC四组癌组织中的表达呈现依次增加的趋势,其中口腔疣状癌的表达低于中分化SCC（P〈0.05）,而与高分化SCC无差别（P〉0.05）。结论：在口腔疣状癌,PTTG1的表达与高分化SCC一致,但低于中分化SCC,从总体上说明口腔疣状癌的生物学行为比中分化SCC好,而与高分化SCC一致;PTTG1与口腔疣状癌的发生可能无关,但可能参与了SCC的发生发展过程。     

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.     

UHRF1在口腔黏膜鳞癌中的表达及其对临床预后的价值研究

目的 分析泛素样含PHD和环指域1(ubiquitin like with PHD and ring finger domains 1,UHRF1)在口腔黏膜鳞状细胞癌中的表达及其临床意义。方法 收集2008—2016年间,于中国科学技术大学附属第一医院口腔颌面外科接受手术治疗的原发性口腔鳞癌患者,利用免疫荧光染色评估患者的肿瘤组织、癌旁正常组织及侵袭前沿中的UHRF1表达,了解其表达差异性。以免疫反应强度分布指数(immunoreactivity intensity distribution index, IRIDI)值4分为界限,将患者分为UHRF1高表达组和低表达组,分析UHRF1表达水平与患者临床病理特征之间的关系,利用Kaplan-Meier法对肿瘤组织中UHRF1表达水平与患者生存率的相关性进行分析,运用Cox风险模型对影响口腔癌患者生存率的相关危险因素进行分析。结果 与肿瘤侵袭前沿、癌旁正常组织相比,UHRF1在口腔鳞癌肿瘤组织中高表达(P<0.01)。口腔鳞癌组织中UHRF1的表达水平与患者性别、肿瘤大小、浸润深度相关(P<0.05)。UHRF1低表达组和高...     

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.     

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.     

Putative cancer stem cell marker expression in oral epithelial dysplasia and squamous cell carcinoma

Multifactorial conditions underlie progression of potentially malignant oral lesions (PMOL) to oral squamous cell carcinoma (OSCC) and there is currently need for better prediction of malignant transformation. The hypothesised existence of cancer stem cells in dysplastic oral tissues provides the potential for more informed assessment of PMOL progression. Semi‐quantitative immunohistochemical assessment of four putative cancer stem cell markers (CD24, CD44, CD271 and ALDH1) was conducted with a training cohort of 107 patient biopsies to establish clinically applicable score threshold values that were subsequently applied to a blind diagnosis in an independent validation cohort of 278 biopsies. Stain intensity scores for ALDH1, CD24 and CD44, but not CD271 were greater for OSCC than normal tissues. The intensity of ALDH1 and CD24 immunostaining correlated with increased oral epithelial disease severity, and CD24 was effective in distinguishing OSCC from non‐malignant tissues, correctly diagnosing 71% of OSCC cases in the validation cohort. Importantly, CD24 immunostaining was effective in diagnosing the presence of dysplasia, correctly discriminating 69% of dysplasia tissues from normal tissues, although no distinction between mild and severe grades of dysplasia was achieved. The results highlight CD24 immunostain intensity as an effective marker of oral dysplasia and OSCC. In conclusion, CD24 immunostain intensity scoring may serve as a helpful technique to assist with the histological recognition of dysplasia in oral biopsies, but not for distinguishing between grades of dysplasia.     

NBS1在口腔鳞癌组织中的表达及意义

目的:检测口腔鳞癌组织(OSCC)中NBS1的表达水平,探讨其与OSCC病理分化级别的相关性以及在肿瘤发生发展中的作用。方法:①采用免疫组化(SP法)检测NBS1蛋白在30例口腔鳞癌组织、9例癌旁组织中的表达。②应用RT-PCR技术检测组织中NBS1的mRNA表达水平。结果:在OSCC与癌旁正常组织中,NBS1 mRNA和蛋白表达差异显著,在口腔癌组织中均表达较高,并随着病理级别增高而增高(P<0.05)。结论:NBS1在不同病理分化程度OSCC中表达水平的差别与多种因素密切相关,与肿瘤的恶性生物学行为有关,其表达水平可成为判断口腔鳞癌侵袭转移和预后的指标之一。     

Metallothionein and p-Akt proteins in oral dysplasia and in oral squamous cell carcinoma: an immunohistochemical study

Background:  Oral leukoplakia (OL) is the main potentially malignant lesion of the oral cavity, and oral squamous cell carcinoma (OSCC) accounts for more than 95% of all malignant neoplasms in the oral cavity. Therefore, the aim of this study was to verify the immunoexpression of p-Akt and Metallothionein (MT) proteins in dysplasic and neoplasic oral lesions.
Methods:  Immunohistochemical studies were carried out on 10 normal epithelium, 30 OL and 15 OSCC paraffin-embedded samples. Immunoperoxidase reaction for p-Akt and MT proteins was applied on the specimens, and the positivity of the reactions was calculated for 1000 epithelial cells.
Results:  Using the ANOVA and the Tukey's post hoc statistical analyses, it was observed a significant difference in the immunoexpression for p-Akt and MT when the OSCC samples were compared with normal and dysplasic epithelial groups. In addition, the Pearson's correlation test showed a significant correlation between the proteins' expression.
Conclusion:  Based on the data obtained, p-Akt and MT activation may play an important role in the conversion of a potentially malignant oral lesion to a malignant carcinoma since its earlier stages.     

Prognostic significance of immunohistochemical biomarkers in oral squamous cell carcinoma

Advances in understanding of the molecular mechanisms underlying oral squamous cell carcinoma (OSCC) have resulted in an increasing number of biomarkers that can be used to predict the behaviour of this disease. The authors conducted a literature review of studies examining the role of immunohistochemistry-based protein biomarkers in predicting OSCC outcome. Only articles published in PubMed-indexed journals over the past 5 years were considered. 22 molecular biomarkers were identified and classified into five groups based on their biological functions: cell cycle acceleration and proliferation; tumour suppression and apoptosis; hypoxia; angiogenesis; and cell adhesion and matrix degradation. The cell cycle acceleration and proliferation biomarkers showed the most divergent prognostic findings. Studies on tumour suppression and apoptosis biomarkers were the most prevalent. There were only a few studies examining molecular biomarkers of hypoxia and angiogenesis, and studies examining cell adhesion and matrix degradation biomarkers have shown that this group has the greatest potential for assessing prognostic parameters. Amongst the several proteins analysed, the immunohistochemical expression levels of epithelial growth factor receptor (EGFR), p53, and matrix metalloproteinases (MMPs) have demonstrated the greatest potential for survival prediction in OSCC, but this review demonstrates that their prognostic relevance is debatable and requires further standardisation.     

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.