Wangxiang Yan

Downregulation of miR-221 Inhibits Cell Migration and Invasion through Targeting Methyl-CpG Binding Domain Protein 2 in Human Oral Squamous Cell Carcinoma Cells

Oral squamous cell carcinoma (OSCC), the most frequent of all oral cancers, is a type of highly malignant tumors with a high capacity to invade locally and form distant metastases. An increasing number of studies have shown that microRNAs (miRNAs) play an important role in regulating cancer metastasis and invasion. In the present study, we detected the expression of miR-221 in two highly metastatic OSCC cell lines and two OSCC cell lines that are less metastatic using quantitative real-time PCR analysis (qRT-PCR). The qRT-PCR results indicate that miR-221 is upregulated in highly metastatic OSCC cell lines. Then, miR-221 expression was knocked down by transfection with miR-221 inhibitor, and UM1 cell migration and invasion were assessed using transwell migration and invasion assays. The results indicate that inhibition of miR-221 suppressed migration and invasion of UM1 cells. Furthermore, methyl-CpG binding domain protein 2 (MBD2) was identified as a direct target gene of miR-221. Additionally, MBD2 silencing could partly reverse the effect of miR-221 on cell migration and invasion. In conclusion, downregulation of miR-221 inhibits cell migration and invasion at least partially through targeting MBD2 in the human OSCC cell line UM1.

Downregulation of miR-221 enhances the sensitivity of human oral squamous cell carcinoma cells to Adriamycin through upregulation of TIMP3 expression.

Aberrantly expressed microRNAs (miRNAs) are involved in oral tumorigenesis since they can alter the expression of proteins involved in cancer progression. It remains unclear whether miRNA-221 influences the resistance of human oral squamous cell carcinoma cells to Adriamycin. We therefore investigated the role of miR-221 in the sensitivity of oral squamous cell carcinoma cells to chemotherapy. Tca8113 and UM2 cells were treated with different concentrations of Adriamycin. Quantitative real-time PCR (qRT-PCR) revealed miR-221 upregulation after Adriamycin treatment of Tca8113 and UM2 cells. By using miR-221 inhibitor mimics, we found that depleting cells of miR-221 increases the sensitivity of the cells to Adriamycin. The expression of tissue inhibitor of metalloproteinase-3 (TIMP3), a target of miR-221, was decreased in cells treated with Adriamycin. TIMP3 depletion reversed the effect of a miR-221 inhibitor mimics on cell survival rates and apoptosis. Together, these results reveal that silencing of miR-221 enhances the sensitivity of human oral squamous cell carcinoma cells to Adriamycin through upregulation of TIMP3 expression.

Craniofacial Fibrous Dysplasia Associated With McCune-Albright Syndrome

t n n w n 18-year-old boy presented to our hospital in Auust 2006 for management of an extremely large leion that was causing considerable distortion of his ace (Fig 1). The patient was an orphan raised by his randmother who had suffered from dementia for ears. Therefore, part of the patient’s clinical history as described by his neighbors, and the information as not as accurate as desired. The patient was said to ave had a rigid tumor-like lesion protruding from the alatal vault into his oral cavity about 10 years previusly. The lesion was estimated to be as large as 3 cm n diameter in the beginning. According to the neighors’ accounts, the lesion may have originated from he left maxilla. The lesion was painless, and inreased very slowly in the early years, but it had been welling rapidly since 2002 (Fig 2), especially in the revious 3 months, and the maximum diameter of the esion had reached 20 cm when he visited our hospial. The giant lesion had caused the patient great ifficulties in speaking, eating, and even breathing. he patient also stated that the lesion had recently ecome painful, and the surface of the lesion often lcerated. For financial reasons, he had not received ny therapy before he visited our hospital.

Hexokinase 2 enhances the metastatic potential of tongue squamous cell carcinoma via the SOD2-H 2 O 2 pathway

The glycolytic enzyme hexokinase (HK2), which is aberrantly expressed in various types of tumours, is associated with metastasis. However, its role in the progression and metastasis of tongue squamous cell carcinoma (TSCC) remains unclear. The results of our study showed that HK2 expression is often deregulated in TSCC patients. Increased HK2 expression was associated with tumour stage, clinical stage, lymph node metastasis, but not pathological grade, and reduced overall survival. Microarray and western blotting analyses revealed increases in HK2 expression in TSCC cells with higher metastatic potential. The following effects were observed with HK2 knockdown: inhibition of cell migration and invasion; reduced SOD2 activity and intracellular H2O2 levels; suppression of pERK1/2, Slug and Vimentin expression; and inhibition of tumour growth and lung metastasis in vivo. Conversely, HK2 overexpression promoted cell migration and invasion, increased SOD2 activity and intracellular H2O2, and enhanced expression of pERK1/2, Slug and Vimentin. Thus, our results demonstrate that deregulation of HK2 expression has an important function in the progression of TSCC and may serve as a biomarker of its metastatic potential in TSCC patients. HK2 enhances the metastatic potential of TSCC by stimulating the SOD2-H2O2 pathway.

Disruption of mediator complex subunit 19 (Med19) inhibits cell growth and migration in tongue cancer

BackgroundMediator complex subunit 19 (Med19) is a critical subunit of the mediator complex that forms a bridge between the transcription factors and RNA polymerase II. Although it has been reported that Med19 plays an important role in stabilizing the whole mediator complex, its biological importance in tongue cancer cell proliferation and migration has not been addressed.MethodsBy using MTT, BrdU incorporation, colony formation, flow cytometric, tumorigenesis and transwell assays, We tested the Med19 role on tongue cancer cell growth and migration.ResultsWe demonstrated that lentivirus-mediated Med19 knockdown could arrest tongue cancer cells at G1 phase, inhibit tongue cancer cell proliferation and migration in vitro. The tumorigenicity of Med19 short hairpin RNA (shRNA)-expressing lentivirus infected tongue cancer cells were decreased after inoculating into nude mice.ConclusionsThese results indicate that Med19 plays an important role in tongue cancer proliferation and migration, and suggest possible applications for tongue cancer therapy.

Dysregulation of AKT1, a miR-138 target gene, is involved in the migration and invasion of tongue squamous cell carcinoma.

BACKGROUND AKT1, also known as PKBα, is abnormally expressed in various malignancies. In this study, we aimed to evaluate the role of AKT1 in the tongue squamous cell carcinoma (TSCC) and further clarify the mechanisms of AKT1 in the migration and invasion of TSCC. METHODS At first, immunohistochemistry (IHC) was conducted to detect the expression of AKT1 in TSCC. Then, we determined the role of AKT1 in the migration and invasion of TSCC and further investigated whether AKT1 was the target gene of miR-138 using dual luciferase reporter assays and Western blot. RESULTS Immunohistochemistry results suggested that AKT1 dysregulation was a frequent event in TSCC, and upregulation of AKT1 was correlated with lymph node metastasis and associated with reduced overall survival. UM1 cells with higher migratory and invasive abilities had more robust AKT1 protein expression than UM2 cells with lower migratory and invasive abilities. The migration and invasion abilities were inhibited in UM1 cells upon AKT1 knockdown, meanwhile resulted in a decline of metastasis-related proteins (vimentin, slug, and pERK1/2), and upregulation of E-cadherin. Luciferase assays revealed that AKT1 was directly targeted by miR-138, and ectopic transfection of miR-138 reduced the expression of AKT1 protein. CONCLUSIONS Our results confirm that upregulation of AKT1, a miR-138 target gene, is a frequent event in TSCC and contributes to the aggressive behaviors and poor prognosis of TSCC.

In vitro effect of iASPP on cell growth of oral tongue squamous cell carcinoma

iASPP is an inhibitory member of the apoptosis-stimulating proteins of P53 (ASPP) family. iASPP is over expressed in several malignant tumors and potentially affects cancer progression. However, the expression and potential role of iASPP in oral tongue squamous cell carcinoma (OTSCC) have not been addressed. In our study, we detected iASPP expression in OTSCC by immunohistochemistry. iASPP expression is up-regulated in OTSCC tissues. Moreover, in clinical pathology specimens, we found that increased iASPP expression correlates with poor differentiation and lymph node metastasis. Using multicellular tumor spheroids (MTS) and flow cytometry, we demonstrated that iASPP down-regulation arrests OTSCC cells at the G0/G1 phase, induces OTSCC cell apoptosis and inhibits OTSCC cell proliferation. These results indicate that iASPP plays a significant role in the progression of OTSCC and may serve as a biomarker or therapeutic target for OTSCC patients.

PIK3CA is critical for the proliferation, invasiveness, and drug resistance of human tongue carcinoma cells.

PIK3CA is an oncogene component of phosphatidylinositol 3-kinase (PI3K) signaling pathway and is associated with cell proliferation and carcinogenesis in a variety of human cancers. PIK3CA mutation is correlated with the aggressiveness of many epithelial cancers. And so PIK3CA is considered as a major oncogene in many human epithelial malignancies. However, its role in tongue carcinoma is unknown. We used lentiviral-mediated interfering short hairpin RNAs (shRNAs) to knock down PIK3CA expression in tongue carcinoma Tca8113 cells, and then we tested the cell proliferation by MTT assay and cell invasiveness by cell invasion assay. To examine whether PIK3CA is involved in the response of Tca8113 cells to an anticancer drug, cisplatin, we further performed cell death analysis by fluorescence-activated cell sorting (FACS). We found that knocking down PIK3CA led to slower cell growth and lessened cell invasiveness. In addition, PIK3CA downregulation increased Tca8113 cell death after cisplatin treatment, suggesting that PIK3CA downregulation might be helpful to increase the effects of some anticancer drugs. Moreover, in a mouse model of established large sized OSCC, we showed that suppression of PIK3CA markedly diminished tumorigenicity in vivo. To understand its molecular mechanism of action, we measured expression of phospho-PTEN (Ser380) and phospho-AKT (Ser473) by Western blot and found that suppression of PIK3CA inhibited OSCC growth through downregulation of p-PTEN and p-AKT. Our study highlights critical roles for PIK3CA in the tongue cancer, and suggests that PIK3CA gene might be considered as a therapeutic target for clinical tongue cancer.

Up-regulation of INSR/IGF1R by C-myc promotes TSCC tumorigenesis and metastasis through the NF-κB pathway

The insulin receptor (INSR) and insulin-like growth factor 1 receptor (IGF1R) have been reported to be involved in the tumorigenesis and metastasis of various malignancies. The aim of our study was to investigate and compare the effects of INSR and IGF1R on the tumorigenesis and metastasis of tongue squamous cell carcinoma (TSCC) and explore the possible mechanism(s) involved. We found that INSR had the same up-regulated expression pattern as IGF1R in TSCC tissues. INSR and IGF1R up-regulation were correlated with each other and associated with lymph node metastasis and poor prognosis. Functional studies established that knocking down either INSR or IGF1R dramatically impeded TSCC cell proliferation, migration, and invasion in vitro and tumorigenesis and tumor metastasis in vivo, whereas ectopic overexpression of INSR or IGF1R enhanced these activities. Both INSR and IGF1R directly targeted p65 and activated the NF-κB pathway; furthermore, C-myc was observed to directly bind to the INSR and IGF1R promoters and up-regulates INSR and IGF1R expression in TSCC. Thus, our current data demonstrate that both INSR and IGF1R are directly targeted by C-myc and exert similar effects to promote the tumorigenesis and metastasis of TSCC through the NF-κB pathway. Therefore, INSR and IGF1R may be therapeutic target genes and potential prognostic factors for TSCC.

High glucose enhances the metastatic potential of tongue squamous cell carcinoma via the PKM2 pathway

Previous evidence has indicated an increased cancer risk in individuals with diabetes mellitus (DM). The aim of this study was to investigate the relationship between DM (high glucose) and tongue squamous cell carcinoma (TSCC) and how high glucose mediated the metastatic potential of TSCC. The relationship between DM and TSCC was assessed in a retrospective study. The role and its mechanism of high glucose on the proliferation, metastatic potential of TSCC were investigated in vitro and in vivo. The prevalence rate of DM in patients with TSCC was 12.84%, which was significantly higher than that (9.7%) in the general population in China. Although no significant difference was observed in the overall survival (OS) rate, TSCC patients with DM have a 1.38-fold increase in relative risk affecting 5-year OS compared to patients without DM. High glucose enhanced the TSCC cell proliferation, migration, invasion and upregulated PKM2 (pyruvate kinase M2) expression. Whereas, these effect was abolished after knockdown of PKM2 in TSCC cells. High glucose promoted tumour growth and lung metastasis of TSCC in a DM animal model. Our results confirm DM as a risk factor for the development of TSCC. High glucose enhances the metastatic potential of TSCC through stimulation of the PKM2 pathway.