Weiliu Qiu

Identification of genes associated with cisplatin resistance in human oral squamous cell carcinoma cell line

BackgroundCisplatin is widely used for chemotherapy of head and neck squamous cell carcinoma. However, details of the molecular mechanism responsible for cisplatin resistance are still unclear. The aim of this study was to identify the expression of genes related to cisplatin resistance in oral squamous cell carcinoma cells.MethodsA cisplatin-resistant cell line, Tca/cisplatin, was established from a cisplatin-sensitive cell line, Tca8113, which was derived from moderately-differentiated tongue squamous cell carcinoma. Global gene expression in this resistant cell line and its sensitive parent cell line was analyzed using Affymetrix HG-U95Av2 microarrays. Candidate genes involved in DNA repair, the MAP pathway and cell cycle regulation were chosen to validate the microarray analysis results. Cell cycle distribution and apoptosis following cisplatin exposure were also investigated.ResultsCisplatin resistance in Tca/cisplatin cells was stable for two years in cisplatin-free culture medium. The IC50 for cisplatin in Tca/cisplatin was 6.5-fold higher than that in Tca8113. Microarray analysis identified 38 genes that were up-regulated and 25 that were down-regulated in this cell line. Some were novel candidates, while others are involved in well-characterized mechanisms that could be relevant to cisplatin resistance, such as RECQL for DNA repair and MAP2K6 in the MAP pathway; all the genes were further validated by Real-time PCR. The cell cycle-regulated genes CCND1 and CCND3 were involved in cisplatin resistance; 24-hour exposure to 10 μM cisplatin induced a marked S phase block in Tca/cisplatin cells but not in Tca8113 cells.ConclusionThe Tca8113 cell line and its stable drug-resistant variant Tca/cisplatin provided a useful model for identifying candidate genes responsible for the mechanism of cisplatin resistance in oral squamous cell carcinoma. Our data provide a useful basis for screening candidate targets for early diagnosis and further intervention in cisplatin resistance.

CCND1 as a predictive biomarker of neoadjuvant chemotherapy in patients with locally advanced head and neck squamous cell carcinoma.

Background 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. Methodology and Findings 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). Conclusions 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.

Experimental Study on Reconstruction of Segmental Mandible Defects Using Tissue Engineered Bone Combined Bone Marrow Stromal Cells With Three-dimensional Tricalcium Phosphate

Reconstructive procedures of segmental mandible defects often require bone graft harvesting, which results in donor site morbidity; the use of tissue-engineered bone might mitigate this problem. The aim of the present experimental pilot study was to produce three-dimensional (3D) autologous tissue-engineered constructs that combine autogenous cultivated bone marrow stromal cells with beta-tricalcium phosphate to reconstruct segmental mandible defects without donor site morbidity. Bone marrow stromal cells were isolated from a dogs caput femoris. After differentiation and proliferation in vitro, the cells were seeded into a 3D beta-tricalcium phosphate scaffold. The constructs were incubated under osteogenic culture conditions for 5 days. Segmental defects of 30 mm length were created unilaterally in the mandibles of the animals. Reconstruction was performed using the construct in three dogs and the scaffold only in three dogs as a control group. The specimens were retrieved 3 months later, and the reconstructed areas were processed for gross observation, radiographic examination, 3D computed tomographic (CT) imaging, biomechanical evaluations, and histologic observation. The construct implanted group (n = 3) showed an average height of the reconstructed area of 18.54 mm and the control group 9.16 mm (P < 0.05). Higher radiodensity was present in the construct group than in the control group, as shown by radiograph. 3D CT imaging showed nearly two-thirds absorption of the reconstructed area in the control group. The biomechanical examination of the construct and control groups showed a compression strength of 102.77 N and 42.90 N and stress of 3.504 N/mm2 and 1.930 N/mm2, which demonstrates significant difference. Histologic micrographs showed new bone formation in the scaffolds in central sections of the defects in the construct group 3 months later, with osteoblast seams, osteoclastic resorption, and cartilage formation. The construct of morphologic, 3D beta-tricalcium phosphate scaffold seeded, autologous bone marrow stromal cells ensure bone formation and vascularization throughout the procedure of mandible segmental defect reconstruction, closely resembling how tissue engineering would be used to reconstruct a segmental mandible defect in the clinical setting.

Effects of irradiation on growth and differentiation-related gene expression in osteoblasts.

Osteoblasts are bone-forming cells that are responsible for the production of bone extracellular matrix. Osteoradionecrosis is a complication of radiation therapy for carcinoma of the head and neck that occurs in 3% to 8.2% of irradiated patients. The irradiation effect on osteoblast differentiation has not been fully elucidated. The objective of our research was to elucidate the effects of radiation on the growth and differentiation-related gene expression in osteoblast in vitro. Three differentiation-related genes, alkaline phosphatase, type I collagen, and osteocalcin, were tested in our experiment. The results showed that radiation inhibited the proliferation of the osteoblasts in a dose-dependent manner and induced G2/M cell cycle arrest. Irradiation, 4 and 8 Gy, enhanced the differentiation-related gene expression of MC3T3-E1 cells 7 days after irradiation. However, the differentiation-related gene expression was decreased 21 days after irradiation in the 4- and 8-Gy groups. This work presents the dynamic phenotypic expression changes of osteoblastic cells after x-ray irradiation.

Different cDNA microarray patterns of gene expression reflecting changes during metastatic progression in adenoid cystic carcinoma

BackgroundThe metastatic ability of tumor cells is determined by level of expression of specific genes that may be identified with the aid of cDNA microarray containing thousands of genes and can be used to establish the expression profile of disease related genes in complex biological system.Materials and MethodsSalivary adenoid cystic carcinoma cell line and its high metastases adenoid cystic carcinoma clone were used as model systems to reveal the gene expression alteration related to metastasis mechanism by cDNA microarray analysis. The correlation of metastatic phenotypic changes and expression levels of 4 selected genes (encoding CD98, L6, RPL29, and TSH) were further validated by using RT-PCR analysis of human tumor specimens from primary adenoid cystic carcinoma and corresponding metastasis lymph nodes.ResultsOf the 7,675 clones of known genes and expressed sequence tags (ESTs) that were analyzed, 30 showed significantly different (minimum 3 fold) expression levels in two cell lines. Out of 30 genes found differentially expressed, 18 were up regulated (with ratio more than 3) and 12 down regulated (with ratio less than 1/3).ConclusionSome of these genes are known to be involved in human tumor antigen, immune surveillance, adhesion, cell signaling pathway and growth control. It is suggested that the microarray in combination with a relevant analysis facilitates rapid and simultaneous identification of multiple genes of interests and in this study it provided a profound clue to screen candidate targets for early diagnosis and intervention.

Clinical management of pediatric aggressive fibromatosis involving the mandible

Pediatric aggressive fibromatosis (AF) is a rare, benign tumor with locally infiltrative growth. Therefore, how to prevent reoccurrence while maintaining the mandible contour and continuity as much as possible is very important when the mandible is involved.

Superficial circumflex iliac artery perforator flap's imaging, anatomy and clinical applications in oral maxillofacial reconstruction

PURPOSE To assess the feasibility of superficial circumflex iliac artery perforator (SCIP) flap for oral maxillofacial reconstruction and evaluate computed tomography angiography (CTA) and color Doppler sonography (CDS) in mapping superficial circumflex iliac artery (SCIA) and its perforators. MATERIAL AND METHODS Fifteen patients were carried out surgery. Perforator identification and the relationship between SCIA, deep circumflex iliac artery (DCIA) and superficial inferior epigastric artery (SIEA) were performed preoperatively and intra-operatively. RESULTS The relationship between SCIA, DCIA and SIEA was depicted and subdivided into type 1 (8/15), type 2 (2/15), type 3 (2/15), type 4 (2/15) and type 5 (1/15). Surgical procedures and SCIP flap anatomy were described. 14/15 of the SCIP flaps survived and one with necrosis. CONCLUSIONS The SCIP flap is a reliable, thin and pliable flap with hidden donor site morbidity for oral maxillofacial reconstruction. CTA and CDS are valuable methods for preoperative assessment of the perforators location and type.

Surgical management of osteoradionecrosis of the jaws.

ObjectiveThe objective of this study is to evaluate our 10-year clinical experience in surgical management of patients with osteoradionecrosis (ORN) unresolved with conservative nonoperative treatment. Patients and MethodsThe medical records of 120 patients who had been surgically treated for ORN during a 10-year period (January 2003 to January 2013) were retrospectively reviewed. ResultsThe most predilection ORN site was mandible (82.5%), followed by the maxilla (11.7%). ORN developed within initial 12 months in 39.2% and within the first 3 years in 68.3%. The median radiation dose was 68.1 Gy (range, 35–148 Gy), but 51 patients (42.5%) experienced ORN even though radiation doses were controlled under 60 Gy. Surgical trauma, as we believed, was the most important factor leading to this result. Among all the patients, 12 (10.0%) patients were found ineligible for operative treatment due to comorbid systematic diseases whereas none healed or improved. In terms of surgical management of the rest of the 108 patients, 90 (75.0%) patients underwent radical resection (4 patients unhealed), and 18 (15.0%) patients underwent mild surgical procedures such as sequestrectomy or debridement (1 patient unhealed). Of the 90 radical resection patients, 58 patients underwent radical resections and immediate microvascular flap reconstruction (19 bone flaps and 39 soft flaps), and 32 patients only experience radical resection (5 patients received second-stage reconstruction). According to follow-up information, 55 patients were free of disease. ConclusionThough priority should be given to surgical treatment for the patient whose ORN does not respond to conservative nonoperative treatment, we may as well take into account more individualized regimens based on ORN severity. A hard lesson learned from our article is that the oral maxillofacial surgeon should minimize the trauma for jaws as possible as he can, especially to patients who need to receive postoperative radiotherapy.

Gorham disease in the maxilla.

Gorham disease is a rare condition that is characterized by the proliferation of thin-walled vascular channels associated with regional osteolysis. The exact etiology of Gorham disease is unknown. The diagnosis of Gorham disease is based on clinical, radiological, and histological features after excluding osteolysis, which is secondary to other pathologic processes. Those pathologic processes include congenital, metabolic, neoplastic, and immunologic etiologies and infections. The appearance of the disease in the craniofacial region often involves the mandible. In the reported literature (English language only), there is 1 reported case of the disease located in the maxilla alone. In this study, we present another case of Gorham disease that presents in the maxilla of a 37-year-old man.

Nomogram model to predict postoperative infection after mandibular osteoradionecrosis surgery

Osteoradionecrosis of the mandible (ORNM) is one of the most dreaded complications of radiotherapy. The poor healing capacity of soft tissue after radiation may lead to surgical failure. The current study was designed to identify prognostic factors for postoperative infection (PPI) and propose corresponding prophylaxis and intervention protocols. A retrospective study was conducted concerning ORNM patients from 2000 to 2015. A risk-stratification score and nomogram model were established to predict the risk of PPI. A total of 257 patients were analyzed, and the total incidence of PPI was 23.3% (60/257). In multiple logistic regression analysis, radiation dose