Jin-song Li

MiR-21 Indicates Poor Prognosis in Tongue Squamous Cell Carcinomas as an Apoptosis Inhibitor

Purpose: We aim to examine miR-21 expression in tongue squamous cell carcinomas (TSCC) and correlate it with patient clinical status, and to investigate its contribution to TSCC cell growth, apoptosis, and tumorigenesis. Experimental Design: MicroRNA profiling was done in 10 cases of TSCC with microarray. MiR-21 overexpression was quantitated with quantitative reverse transcription-PCR in 103 patients, and correlated to the pathoclinical status of the patients. Immunohistochemistry was used to examine the expression of TPM1 and PTEN, and terminal deoxynucleotidyl transferase–mediated dUTP labeling to evaluate apoptosis. Moreover, miR-21 antisense oligonucleotide (ASO) was transfected in SCC-15 and CAL27 cell lines, and tumor cell growth was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, adherent colony formation, and soft agar assay, whereas apoptosis was determined by Annexin V assay, cytochrome c release, and caspase 3 assay. Tumorigenesis was evaluated by xenografting SCC-15 cells in nude mice. Results: MiR-21 is overexpressed in TSCC relative to adjacent normal tissues. The level of miR-21 is reversely correlated with TPM1 and PTEN expression and apoptosis of cancer cells. Multivariate analysis showed that miR-21 expression is an independent prognostic factor indicating poor survival. Inhibiting miR-21 with ASO in TSCC cell lines reduces survival and anchorage-independent growth, and induces apoptosis in TSCC cell lines. Simultaneous silencing of TPM1 with siRNA only partially recapitulates the effect of miR-21 ASO. Furthermore, repeated injection of miR-21 ASO suppresses tumor formation in nude mice by reducing cell proliferation and inducing apoptosis. Conclusions: miR-21 is an independent prognostic indicator for TSCC, and may play a role in TSCC development by inhibiting cancer cell apoptosis partly via TPM1 silencing.

MiR-200b and miR-15b regulate chemotherapy-induced epithelial-mesenchymal transition in human tongue cancer cells by targeting BMI1

Chemotherapy has been reported to induce epithelial-mesenchymal transition (EMT) in tumor cells, which is a critical step in the process of metastasis leading to cancer spreading and treatment failure. However, the underlying mechanisms of chemotherapy-induced EMT remain unclear, and the involvement of microRNAs (miRNA) in this process is poorly understood. To address these questions, we established stable chemotherapy-resistant tongue squamous cell carcinoma (TSCC) cell lines CAL27-res and SCC25-res by exposing the parental CAL27 and SCC25 lines to escalating concentrations of cisplatin for 6 months. CAL27-res and SCC25-res cells displayed mesenchymal features with enhanced invasiveness and motility. MiRNA microarray illustrated that miR-200b and miR-15b were the most significantly downregulated microRNAs in CAL27-res cells. Ectopic expression of miR-200b and miR-15b with miRNA mimics effectively reversed the phenotype of EMT in CAL27-res and SCC25-res cells, and sensitized them to chemotherapy, but inhibition of miR-200b and miR-15b in the sensitive lines with anti-sense oligonucleotides induced EMT and conferred chemoresistance. Retrieving the expression of B lymphoma Mo-MLV insertion region 1 homolog (BMI1), a target for miR-200b and miR-15b, in the presence of the miRNA mimics by transfecting CAL27-res cells with pcDNA3.1–BMI1-carrying mutated seed sequences of miR-200b or miR-15b at its 3′-UTR recapitulated chemotherapy-induced EMT. In vivo, enforced miR-200b or miR-15b expression suppressed metastasis of TSCC xenografts established by CAL27-res cells. Clinically, reduced miR-200b or miR-15b expression was associated with chemotherapeutic resistance in TSCCs and poor patient survival. Our data suggest that reduced expression of miR-200b and miR-15b underscores the mechanisms of chemotherapy-induced EMT in TSCC, and may serve as therapeutic targets to reverse chemotherapy resistance in tongue cancers.

A review of clinical and histological parameters associated with contralateral neck metastases in oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) has a high incidence of cervical micrometastases and sometimes metastasizes contralaterally because of the rich lymphatic intercommunications relative to submucosal plexus of oral cavity that freely communicate across the midline, and it can facilitate the spread of neoplastic cells to any area of the neck consequently. Clinical and histopathologic factors continue to provide predictive information to contralateral neck metastases (CLNM) in OSCC, which determine prophylactic and adjuvant treatments for an individual patient. This review describes the predictive value of clinical‐histopathologic factors, which relate to primary tumor and cervical lymph nodes, and surgical dissection and adjuvant treatments. In addition, the indications for elective contralateral neck dissection and adjuvant radiotherapy (aRT) and strategies for follow‐up are offered, which is strongly focused by clinicians to prevent later CLNM and poor prognosis subsequently.

miR‐639 regulates transforming growth factor beta‐induced epithelial–mesenchymal transition in human tongue cancer cells by targeting FOXC1

Epithelial‐to‐mesenchymal transition (EMT) is implicated in embryonic development and various pathological events. Transforming growth factor beta (TGFβ) has been reported to induce EMT in tumor cells, which is a critical step in the process of metastasis leading to cancer spreading and treatment failure. However, the involvement of microRNA during the EMT process in tongue squamous cell carcinoma (TSCC) remains to be determined. To address this question, TSCC cell lines SCC9 and CAL27 were treated with human recombinant TGFβ1 for 48 h. miRNA microarray illustrated that miR‐639 was significantly downregulated in TGFβ‐treated SCC9 cells. Ectopic expression of miR‐639 with miRNA mimics effectively blocked TGFβ‐induced EMT in SCC9 and CAL27 cells, but inhibition of miR‐639 in SCC9 and CAL27 cells with antisense oligonucleotides induced EMT. Computational microRNA target predictions detected a conserved sequence matching to the seed region of miR‐639 in the 3′‐UTR of FOXC1 mRNA. Luciferase reporter assays revealed that miR‐639 targets FOXC1. Ectopic expression of FOXC1 induces EMT in TSCC cells. Silencing FOXC1 expression blocked TGFβ‐induced EMT in SCC9 cells. Clinically, reduced miR‐639 expression was associated with metastasis in TSCC and poor patient survival. The data from the present study suggest that reduced expression of miR‐639 underscores the mechanism of TGFβ‐induced EMT in TSCC by targeting FOXC1 and may serve as therapeutic targets in the process of metastasis.

Long non-coding RNA NKILA inhibits migration and invasion of tongue squamous cell carcinoma cells via suppressing epithelial-mesenchymal transition

Long non-coding RNAs (lncRNAs) have emerged recently as key regulators of tumor development and progression. Our previous study identified an NF-KappaB interacting lncRNA (NKILA) which was negatively correlated with breast cancer metastasis and patient prognosis. However, its clinical significance and potential role in Tongue squamous cell carcinoma (TSCC) remain unclear. Here we show that NKILA is down-regulated in TSCC cancer tissues than that in matched adjacent noncancerous tissues. And low NKILA expression in TSCC is significantly correlated with tumor metastasis and poor patient prognosis. In vitro, overexpression of NKILA decreases TSCC cells migration and invasion. Mechanistic study shows that NKILA inhibits the phosphorylation of IκBα and NF-κB activation as well as the induction of the epithelial-mesenchymal transition (EMT) process. Ectopic expression of NKILA in Tscca cells inhibits NF-κB activator TNF-α-promoted cell migration and invasion, while applying NF-κB inhibitor Bay-117082 or JSH-23 in NKILA silenced CAL27 cells reverses cell migration capacity to lower level. In vivo experimental metastasis model also demonstrates NKILA inhibits lung metastasis of NOD/SCID mice with TSCC tumors. These results suggested that NKILA is a vital determinant of TSCC migration and invasion and NF-κB signaling pathway mediates this effect. Given the above mentioned function of NKILA, it could act as a potential predictor for overall survival in patients with TSCC and a potential therapeutic target for TSCC intervention.

MiR-320a acts as a prognostic factor and Inhibits metastasis of salivary adenoid cystic carcinoma by targeting ITGB3

BackgroundSalivary Adenoid cystic carcinoma (SACC) patients with local invasion and lung metastasis are often resistant to conventional therapy such as operation, chemotherapy and radiotherapy. To explore the underling mechanisms, we studied the roles of miRNA in regulating invasiveness of SACC cells.MethodsMicroRNA profiling was done in SACC cells with microarray. MiRNA mimics or antisense oligonucleotide was transfected and invasiveness of SACC cells was evaluated by adhesion assay and transwell assay. The target gene of miRNA was identified by luciferase reporter assay and “rescue” experiment. Tumor metastasis was evaluated by BALB/c-nu mice xenografts. MiRNA and its target gene expression were identified by in-situ hybridization and immunohistochemistry respectively, in 302 patients from affiliated hospitals of Sun Yat-sen University and in 148 patients from affiliated hospitals of Central South University, and correlated to the clinicopathological status of the patients.ResultsMiR-320a was down-regulated in high lung metastatic ACCM and SACC-LM cells compared with the corresponding low metastatic ACC2 and SACC-83 cells, and inhibited adhesion, invasion and migration of SACC cells by targeting integrin beta 3 (ITGB3). In vivo, enforced miR-320a expression suppressed metastasis of SACC xenografts. In the two independent sets, miR-320a was downregulated in primary SACCs with metastasis compared to those without metastasis, and low expression of this miRNA predicts poor patient survival and rapid metastasis. Multivariate analysis showed that miR-320a expression was an independent indicator of lung metastasis.ConclusionsMiR-320a inhibits metastasis in SACCs by targeting ITGB3 and may serve as a therapeutic target and prognostic marker in salivary cancers.

miR-483-5p determines mitochondrial fission and cisplatin sensitivity in tongue squamous cell carcinoma by targeting FIS1

Mitochondria play an important role in the initiation of apoptosis. However, whether cisplatin can induce apoptosis by initiating a mitochondrial fission pathway and the mechanism underlying this effect remain poorly understood. In this study, we show that the mitochondrial fission protein FIS1 is upregulated upon cisplatin treatment in tongue squamous cell carcinoma (TSCC) cells. FIS1 knockdown can attenuate mitochondrial fission and cisplatin sensitivity. We found that FIS1 is a direct target of miR-483-5p and that miR-483-5p can inhibit mitochondrial fission and cisplatin sensitivity in vitro and in vivo. Furthermore, we found that miR-483-5p and FIS1 are significantly associated with cisplatin sensitivity and with overall survival in patients with TSCC in a retrospective analysis of multiple centers. This study revealed that a novel mitochondrial fission pathway composed of miR-483-5p and FIS1 regulates cisplatin sensitivity. The modulation of miR-483-5p and FIS1 levels may provide a new approach for increasing cisplatin sensitivity.

A role for cancer-associated fibroblasts in inducing the epithelial-to-mesenchymal transition in human tongue squamous cell carcinoma

OBJECTIVES Lymph node metastasis is a prominent clinical feature of tongue squamous cell carcinoma (TSCC) and is associated with a higher mortality rate. Carcinoma-associated fibroblasts (CAFs), a major component of the tumor microenvironment (TME), play an important role in tumor progression, and are associated with a poor prognosis. The aim of this study was to examine the role of CAFs in promoting the invasion of TSCC through the epithelial-to-mesenchymal transition (EMT). MATERIALS AND METHODS A series of matched CAF and normal fibroblast (NF) pairs were assessed for cell morphology and for the expression of alpha smooth muscle actin (α-SMA), stromal cell-derived factor-1 (SDF1), fibroblast-activating protein (FAP), vimentin, and cytokeratin (CK) markers. Transwell assays, Western blot analysis, reverse transcription-PCR, and immunofluorescence staining were used to assess the role of CAFs, as compared to that of NFs, in promoting proliferation, migration, invasion, and EMT in TSCC. RESULTS Both CAF and NF primary cultures expressed vimentin but not CK. CAFs showed significantly higher α-SMA protein levels, SDF1 secretion, and mRNA levels of α-SMA, SDF1, and FAP. We also found that co-culture with CAFs enhanced the proliferation and invasion of SCC9 cells. Moreover, co-culture with CAFs induced upregulation of the EMT markers fibronectin and vimentin, downregulation of E-cadherin, and enhanced invasion in SCC9 cells. CONCLUSION These results suggest that CAFs induce EMT marker expression and functional changes in TSCCs.

CXCL2/MIF-CXCR2 signaling promotes the recruitment of myeloid-derived suppressor cells and is correlated with prognosis in bladder cancer.

The accumulation of myeloid-derived suppressor cells (MDSCs) has been observed in solid tumors and is correlated with tumor progression; however, the underlying mechanism is still poorly understood. In this study, we identified a mechanism by which tumor cells induce MDSC accumulation and expansion in the bladder cancer (BC) microenvironment via CXCL2/MIF-CXCR2 signaling. Elevated expression of CXCL2 and MIF and an increased number of CD33+ MDSCs were detected in BC tissues, and these increases were significantly associated with advanced disease stage and poor patient prognosis (P<0.01). A positive association was observed between CXCL2 or MIF expression and the number of tumor-infiltrating CD33+ MDSCs (P<0.01). Subsequently, we demonstrated that CD45+CD33+CD11b+HLA-DR− MDSCs from fresh BC tissues displayed high levels of suppressive molecules, including Arg1, iNOS, ROS, PDL-1 and P-STAT3, and stronger suppression of T-cell proliferation. Interestingly, these CD45+CD33+CD11b+HLA-DR− MDSCs exhibited increased CXCR2 expression compared with that in peripheral blood from BC patients or healthy controls (P<0.05). Chemotaxis assay revealed that bladder cancer cell line J82 induced MDSC migration via CXCL2/MIF-CXCR2 signaling in vitro. Mechanistic studies demonstrated that J82-induced MDSC trafficking and CXCR2 expression were associated with increased phosphorylation of p38, ERK and p65. Conversely, inhibition of the phosphorylation of p38, ERK or p65 decreased J82-induced MDSC trafficking and CXCR2 expression. CXCL2/MIF-stimulated activation of the mitogen-activated protein kinase and nuclear factor kappa B pathways in MDSCs was MyD88 dependent. Overall, our results identify the CXCL2/MIF-CXCR2 axis as an important mediator in MDSC recruitment and as predictors and potential therapeutic targets in BC patients.

Quality of life of patients with tongue cancer 1 year after surgery.

PURPOSE To study the changes and factors affecting the quality of life (QOL) of patients with tongue cancer 1 year after primary surgery. PATIENTS AND METHODS A total of 289 consecutive patients with tongue cancer who had undergone primary surgery from 2003 to 2008 at our hospital were recruited. Patient QOL was evaluated using the University of Washington Quality of Life Questionnaire, version 4. Statistical analysis was conducted using a paired-samples t test and multiple stepwise linear regression with Statistical Package for Social Sciences, version 11.5 (SPSS, Chicago, IL). RESULTS At 1 year after surgery, the appearance, activity, speech, swallowing, shoulder function, salivary, and taste domain scores were significantly lower than the preoperative scores (P < .05). However, the pain, anxiety, and mood scores were significantly better 1 year after surgery (P < .05). The overall QOL had increased greatly 1 year after surgery but did not reach the pretreatment level. Multiple stepwise linear regression analysis showed that the main factors affecting QOL were radiotherapy, advanced clinical stage (P < .05), socioeconomic status, and patient age. Radiotherapy, advanced clinical stage (P < .05), socioeconomic status, and age (P < .05) were independently associated with QOL. CONCLUSIONS The patients with tongue cancer who have been diagnosed and treated early might have a better QOL. A greater socioeconomic status can also improve the QOL of patients with tongue cancer after primary surgery.