Identification of pyruvate kinase type M2 as potential oncoprotein in squamous cell carcinoma of tongue through microRNA profiling.

MicroRNAs (miRNAs) are noncoding RNAs with specific regulatory role in gene expression. Recent reports suggested their involvement in human malignancies. Currently, there is no information concerning miRNA expression and functions in squamous cell carcinoma (SCC) of tongue. In this study, we evaluated the expression patterns of 156 mature miRNAs in tongue SCC using Taqman-based microRNA assays. Of these 156 miRNAs, miR-133a and miR-133b were significantly reduced in tongue SCC cells in comparison with the paired normal epithelial cells. Tongue SCC cell lines transfected with miR-133a and miR-133b precursors displayed reduction in proliferation rate. In addition, the number of apoptotic cells was increased in response to the introduction of precursors. Computational target gene prediction suggested that both miR-133a and miR-133b are targeting transcript of pyruvate kinase type M2 (PKM2), a potential oncogene in solid cancers. In tongue SCC cell lines, PKM2 expression was reduced in response to miR-133a and miR-133b precursors transfection. Immunohistochemical staining results of tongue SCC tissues suggested that PKM2 was overexpressed in tongue SCC and was associated with the downregulation of miR-133a and miR-133b. Our results suggested that aberrant reduction of miR-133a and miR-133b was associated with the dysregulation of PKM2 in SCC of tongue.

Preservation of lateral thoracic artery to improve vascular supply of distal skin without compromising pedicle length in harvesting pectoralis major myocutaneous flap.

The pectoralis major myocutaneous (PM) flap is supplied by three arterial systems. The lower chest skin of the PM flap is mainly supplied by the branches of lateral thoracic artery and internal mammary artery. The conventional harvesting technique for head and neck reconstruction utilizes single arterial supply from the pectoral branch of thoracoacromial artery. The distal skin island of PM flap is therefore compromised and requires indirect blood supply by communicating vessels. In harvesting the PM flap, the pectoralis minor muscle is divided to preserve the lateral thoracic artery and its blood supply to the lateral distal skin island of PM flap without compromising the pedicle length for head and neck reconstruction. Six PM flaps were harvested for reconstruction of head and neck defects with preservation of both the pectoral artery and lateral thoracic artery. The focal pint of swing of all six flaps was at the same point just below the mid-point of clavicle for both pectoral artery and lateral thoracic artery. The flaps can reach the oral cavity, tonsil or hypopharynx without limitation and there is no flap necrosis. In conclusion, the lateral thoracic artery can be preserved without compromising the pedicle length of PM flap. It is a recommended technique to improve the blood supply to the distal skin of PM flap.

Prognostic factors of clinically stage I and II oral tongue carcinoma-A comparative study of stage, thickness, shape, growth pattern, invasive front malignancy grading, Martinez-Gimeno score, and pathologic features.

PURPOSE: This study aims at evaluation of the different prognostic models, including stage, tumor thickness, shape, malignancy grading of tumor invasive front, Martinez-Gimeno score, and pathologic features in the prediction of subclinical nodal metastasis, local recurrence, and survival of early T1 and T2 oral tongue squamous cell carcinoma. The results will have important implication for the management of patients. PATIENTS AND METHODS: Seventy-two clinically T1 and T2 glossectomy specimens of oral tongue carcinoma were serially sectioned in 3-mm thickness for the evaluation of various pathologic features. The prognostic value in the prediction of subclinical nodal metastasis, local recurrence, and survival of different models were compared. RESULTS: Among all the tumor parameters and predictive models being evaluated, tumor thickness was the only significant factor that had significant predictive value for subclinical nodal metastasis, local recurrence, and survival. With the use of 3-mm and 9-mm division, tumor of up to 3-mm thickness has 8% subclinical nodal metastasis, 0% local recurrence, and 100% 5-year actuarial disease-free survival; tumor thickness of more than 3 mm and up to 9 mm had 44% subclinical nodal metastasis, 7% local recurrence, and 76% 5-year actuarial disease-free survival; tumor of more than 9 mm had 53% subclinical nodal metastasis, 24% local recurrence, and 66% 5-year actuarial disease-free survival. CONCLUSIONS: Tumor thickness should be considered in the management planning of patients with early oral tongue carcinoma.