BRAF V600E Mutation Analysis in Papillary Thyroid Carcinomas by Peptide Nucleic Acid Clamp Real-time PCR

Background

Activating somatic mutation of the BRAF ^V600E has been identified as the most common genetic event in papillary thyroid carcinoma (PTC) with a variable frequency (32–87 %) in different series by different methods. The BRAF ^V600E mutation is associated with various clinicopathological parameters. The mutation is an important factor for the management of the PTC patients. The objective of this study was to detect the BRAF ^V600E mutation in PTCs by peptide nucleic acid (PNA) clamp real-time PCR and to analyze the results with clinicopathological parameters.

Methods

We performed genetic analysis of BRAF ^V600E by PNA clamp real-time PCR in 211 PTCs in Korea, stratified by clinicopathological parameters.

Results

The BRAF ^V600E mutation was detected in 90 % of PTC cases, and it occurred significantly more often in female patients than in male patients (p = 0.001). The clinicopathological parameters of age, tumor size, and disease stage were not associated with the BRAF ^V600E mutation, while extrathyroid invasion (p = 0.031), lymph nodal metastasis (p = 0.002), and tumor multiplicity (p = 0.020) were.

Conclusions

The prevalence (90 %) of the BRAF ^V600E mutation in this study is the highest ever reported, confirming the key role of this mutation in PTC tumorigenesis. The BRAF ^V600E mutation was associated with aggressive clinical behaviors including extrathyroid invasion, lymph nodal metastasis and tumor multifocality. The PNA clamp real-time PCR method for the BRAF ^V600E mutation detection is sensitive and is applicable in a clinical setting.     

Leucine‐rich glioma inactivated 3 promotes HaCaT keratinocyte migration

Our finding that human skin expresses leucine‐rich glioma inactivated 3 (LGI3) raises the question of the function of this cytokine in keratinocytes. We have shown that LGI3 stimulates human HaCaT keratinocyte migration without affecting viability or proliferation. Western blot analysis showed that LGI3 induced focal adhesion kinase activation, Akt phosphorylation, and glycogen synthase kinase 3β (GSK3β) phosphorylation in these cells. Using the scratch wound assay and a modified Boyden chamber, we found that LY294002, a selective phosphatidylinositol 3‐kinase inhibitor, and LiCl, a selective GSK3β inhibitor, abolished LGI3‐induced cell migration. We tested β‐catenin levels after LGI3 treatment because the Akt‐GSK3β pathway regulates β‐catenin accumulation, and β‐catenin promotes cell migration. LGI3 treatment increased β‐catenin protein and nuclear localization, whereas LY294002 prevented LGI3‐induced focal adhesion kinase and Akt activation as well as β‐catenin accumulation. Overall, these data suggest that LGI3 stimulates HaCaT cell migration following β‐catenin accumulation through the Akt pathway.     

Predicting Nipple–Areolar Involvement Using Preoperative Breast MRI and Primary Tumor Characteristics

Background

Preoperative assessment of the nipple–areolar complex (NAC) is invaluable when considering nipple-sparing mastectomy. Our hypothesis is that breast magnetic resonance imaging (MRI) may predict involvement of the NAC with tumor.

Methods

Clinical, histopathologic, and imaging data were compiled for patients who underwent preoperative breast MRI followed by mastectomy or nipple-sparing mastectomy for malignancy between 2006 and 2009. Blinded rereview of all MRI studies was performed by a breast MRI imager and compared to initial MRI findings. Multivariate analysis identified variables predicting NAC involvement with tumor.

Results

Of 77 breasts, 18 (23 %) had tumor involving or within 1 cm of the NAC. The sensitivity of detecting histopathologically confirmed NAC involvement was 61 % with history and/or physical examination, and 56 % with MRI. Univariate analysis identified the following variables as significant for NAC involvement: large tumors near the nipple on preoperative MRI, node-positive disease, invasive lobular carcinoma, advanced histopathologic T stage, and neoadjuvant chemotherapy. On multivariate analysis, only tumor size >2 cm and distance from tumor edge to the NAC <2 cm on MRI maintained significance. Pearson correlation coefficient for MRI size compared to histopathologic size was 0.53 (P < 0.0001).

Conclusions

MRI is not superior to thorough clinical evaluation for predicting tumor in or near the NAC. However, MRI-measured tumor size and distance from the NAC are correlated with increased risk of NAC involvement. The combination of preoperative history and physical examination, tumor characteristics, and breast MRI can aid the surgeon in predicting a tumor-involved nipple more than any single modality alone.     

Latissimus dorsi flap coverage of soft tissue defect following below-knee amputation: emphasis on flap design and recipient vessels

High-energy trauma to the lower extremity often results in amputation of the limb. For maximal preservation of limb length during amputation, free tissue transfer is often necessary. In this study, we report our experience of stump coverage using latissimus dorsi musculocutaneous flaps with an emphasis on flap design and recipient vessels. Between January 2005 and September 2010, twelve patients with severe traumatic injuries to the lower leg underwent below-knee amputations with stump coverage using latissimus dorsi free flaps. The primary and secondary cases were approached differently regarding the flap design and recipient vessels. All flaps survived completely. There were 8 primary cases and 4 secondary cases. In the primary cases, the anterior tibial artery was used as the recipient vessel in 6 cases, and in 2 cases, the descending geniculate artery was used. In the secondary cases, the descending geniculate artery was used in all cases. There were two cases of ulceration on the grafted non-weight-bearing site, but after the usage of collagen–elastin artificial dermis, no ulcerations were seen. The latissimus dorsi musculocutaneous flap is the most feasible option for coverage of amputation stumps. In flap design, the width of the skin paddle must match the anteroposterior diameter of the defect at the stump. The latissimus dorsi muscle must sufficiently wrap the bony stump for padding. We recommend using the anterior tibial artery as a recipient vessel in primary cases, and the descending geniculate artery in secondary cases.