[Show abstract][Hide abstract] ABSTRACT: Summary Patients with advanced head and neck squamous cell carcinoma (HNSCC) have a poor prognosis with the currently available therapy, and tumor recurrence is frequently observed. The discovery of specific membrane-associated cancer stem cell (CSC) markers is crucial for developing novel therapeutic strategies to target these CSCs. To address this issue, we established sphere cultures to enrich CSCs and used them for plasma membrane proteomics to identify specific membrane signatures of the HNSCC spheres. Of a total data set that included 376 identified proteins, 200 were bona fide membrane proteins. Among them, 123 proteins were at least 1.5-fold up- or down-regulated in the spheres compared with the adherent cultures. These proteins included cell adhesion molecules, receptors, and transporter proteins. Some of them play key roles in wnt, integrin and TGF&beta signaling pathways. Comparing our dataset with two published hESC membrane protein signatures, we found 18 proteins common to all three of the databases. CD166 and CD44 were two of them. Interestingly, the expression of CD166, rather than that of the well-established HNSCC CSCs marker CD44, was significantly related to the malignant behavior of HNSCC. Compared with CD166low HNSCC cells, CD166high HNSCC cells had a greater sphere-formation ability in vitro and tumor formation ability in vivo. Patients whose tumors expressed high levels of CD166 had a significantly poorer clinical outcome than those whose tumors expressed low levels of CD166 (cohort 1: 96 cases, p=0.040), while the level of CD44 expression had only a marginal influence on the clinical outcome of patients with HNSCC (p=0.078). The level of CD166 expression in HNSCC tumors was also associated with the tumor recurrence rate (cohort 2: 104 cases, p=0.016). This study demonstrates that CD166 is a valuable cell surface marker for the enrichment of HNSCC stem cells and that plasma membrane proteomics is a promising biological tool for investigating the membrane proteins of CSCs.
[Show abstract][Hide abstract] ABSTRACT: J Oral Pathol Med (2013)42: 140–147
Background: The carcinogenesis mechanism of adenoid cystic carcinoma (ACC) of the salivary gland is poorly understood. MicroRNA155 (miRNA155) has been involved in the carcinogenesis of many malignant tumors. The present study aims to examine the role of miRNA155 in tumor growth and invasion of ACC.
Methods: MiRNA155 expression was determined in ACC specimens along with normal salivary glands by quantitative PCR. Using ACC-2 cells as a model for ACC, cell proliferation was examined by MTT assay after knocking down miRNA155 expression, and cell cycle analysis was performed. Invasive capacity of ACC-2 cells was examined by a Transwell culture assay. The effect of miRNA155 on tumor growth was also examined in vivo using mouse models. The effect of miRNA155 on epidermal growth factor receptor (EGFR)/NF-κB was studied by quantitative PCR and electrophoretic mobility shift assay.
Results: MiRNA155 was over-expressed in ACC. Proliferation of ACC-2 cells was markedly inhibited by knocking down miRNA155, resulting from a blockade of cell cycle in the G1 phase. Inhibition of miRNA155 significantly suppressed the invasive capacity of ACC-2 cells. In vivo growth of ACC-2 cell-derived tumors was significantly slower by inhibition of miRNA155. Inhibition of miRNA155 also resulted in decreased expression of EGFR and RelA (NF-κB).
Conclusion: The results suggest that miRNA155 facilitates cell cycle progression and promotes invasion in ACC and that the EGFR/NF-κB pathway might participate in mediating the effects of miRNA155. This study has provided insights into the carcinogenic mechanisms of ACC and identified new targets for intervention of salivary ACC.
No preview · Article · Jul 2012 · Journal of Oral Pathology and Medicine
[Show abstract][Hide abstract] ABSTRACT: Oral squamous papilloma and papillary squamous cell carcinoma are 2 clinicopathologically distinctive papillary epithelial tumors. The current study aims to compare the clinical and pathologic features of these oral papillary lesions in a patient population from eastern China. A retrospective review in a series of patients with clinical and pathologic diagnosis of oral squamous papilloma (n = 141) and papillary squamous cell carcinoma (n = 56) was conducted. The average age of oral squamous papilloma was 51.0 years (male-to-female ratio, 1.82), with the palate being the predominant site. The average age of oral papillary squamous cell carcinoma was 63.3 years (male-to-female ratio, 1.67), with the gingiva being the predominant site. Multivariate analysis revealed that the elderly patient with papillary lesion (≥60 years) was associated with 3.09-fold (95% confidence interval, 1.59-6.03) increased carcinoma risk compared with the nonelderly patient. The lesion located on the gingiva was associated with 4.98-fold (95% confidence interval, 1.96-12.63) increased carcinoma risk compared with other oral sites. Collectively, clinicopathologic features of oral squamous papilloma and papillary squamous cell carcinoma in eastern China were elucidated. Elderly patients with oral papillary lesions located on the gingiva correlate with higher carcinoma risk. It highlights the importance of using a histologic examination to confirm the clinical diagnosis for any suspicious papillary lesions.
No preview · Article · May 2012 · Annals of diagnostic pathology
[Show abstract][Hide abstract] ABSTRACT: Cyclin D1 (CCND1) has been associated with chemotherapy resistance and poor prognosis. In this study, we tested the hypothesis that CCND1 expression determines response and clinical outcomes in locally advanced head and neck squamous cell carcinoma (HNSCC) patients treated with neoadjuvant chemotherapy followed by surgery and radiotherapy.
224 patients with HNSCC were treated with either cisplatin-based chemotherapy followed by surgery and radiotherapy (neoadjuvant group, n = 100) or surgery and radiotherapy (non-neoadjuvant group, n = 124). CCND1 expression was assessed by immunohistochemistry. CCND1 levels were analyzed with chemotherapy response, disease-free survival (DFS) and overall survival (OS). There was no significant difference between the neoadjuvant group and non-neoadjuvant group in DFS and OS (p = 0.929 and p = 0.760) when patients treated with the indiscriminate administration of cisplatin-based chemotherapy. However, in the neoadjuvant group, patients whose tumors showed a low CCND1 expression more likely respond to chemotherapy (p<0.001) and had a significantly better OS and DFS than those whose tumors showed a high CCND1 expression (73% vs 8%, p<0.001; 63% vs 6%, p<0.001). Importantly, patients with a low CCND1 expression in neoadjuvant group received more survival benefits than those in non-neoadjuvant group (p = 0.016), however patients with a high CCND1 expression and treated with neoadjuvant chemotherapy had a significantly poor OS compared to those treated with surgery and radiotherapy (p = 0.032). A multivariate survival analysis also showed CCND1 expression was an independent predictive factor (p<0.001).
This study suggests that some but not all patients with HNSCC may benefit from neoadjuvant chemotherapy with cisplatin-based regimen and CCND1 expression may serve as a predictive biomarker in selecting patients undergo less than two cycles of neoadjuvant chemotherapy.