Increased cytoplasmic levels of CIS, SOCS1, SOCS2, or SOCS3 are required for nuclear translocation.

We investigated the cellular localization of ectopically-expressed CIS, SOCS1, SOCS2 and SOCS3 proteins. We found that SOCS proteins localize to the nucleus where they reduce Stat3 proteins and that the presence of proteasome inhibitors increased SOCS nuclear localization. Our results indicate that increased nuclear localization resulted from increased levels of SOCS proteins in the cytoplasm. Finally, we demonstrate that the same effect occurs with endogenously-expressed SOCS proteins. These observations suggest that increased cytoplasmic levels of proteins in the SOCS family are regulated through nuclear translocation.

Breast cancer diagnosis using a microfluidic multiplexed immunohistochemistry platform.

BACKGROUND: Biomarkers play a key role in risk assessment, assessing treatment response, and detecting recurrence and the investigation of multiple biomarkers may also prove useful in accurate prediction and prognosis of cancers. Immunohistochemistry (IHC) has been a major diagnostic tool to identify therapeutic biomarkers and to subclassify breast cancer patients. However, there is no suitable IHC platform for multiplex assay toward personalized cancer therapy. Here, we report a microfluidics-based multiplexed IHC (MMIHC) platform that significantly improves IHC performance in reduction of time and tissue consumption, quantification, consistency, sensitivity, specificity and cost-effectiveness. METHODOLOGY/PRINCIPAL FINDINGS: By creating a simple and robust interface between the device and human breast tissue samples, we not only applied conventional thin-section tissues into on-chip without any additional modification process, but also attained perfect fluid control for various solutions, without any leakage, bubble formation, or cross-contamination. Four biomarkers, estrogen receptor (ER), human epidermal growth factor receptor 2 (HER2), progesterone receptor (PR) and Ki-67, were examined simultaneously on breast cancer cells and human breast cancer tissues. The MMIHC method improved immunoreaction, reducing time and reagent consumption. Moreover, it showed the availability of semi-quantitative analysis by comparing Western blot. Concordance study proved strong consensus between conventional whole-section analysis and MMIHC (n = 105, lowest Kendall's coefficient of concordance, 0.90). To demonstrate the suitability of MMIHC for scarce samples, it was also applied successfully to tissues from needle biopsies. CONCLUSIONS/SIGNIFICANCE: The microfluidic system, for the first time, was successfully applied to human clinical tissue samples and histopathological diagnosis was realized for breast cancers. Our results showing substantial agreement indicate that several cancer-related proteins can be simultaneously investigated on a single tumor section, giving clear advantages and technical advances over standard immunohistochemical method. This novel concept will enable histopathological diagnosis using numerous specific biomarkers at a time even for small-sized specimens, thus facilitating the individualization of cancer therapy.

Detection of BRAFV600E mutation on fine needle aspiration specimens of thyroid nodule refines cyto-pathology diagnosis, especially in BRAF600E mutation-prevalent area.

BACKGROUND: Between 10 and 30% of the fine needle aspiration biopsies (FNABs) of thyroid nodules are diagnosed as 'indeterminate'. A molecular diagnostic method is needed to reduce unnecessary surgery in this group. In Korea, most thyroid cancer is the classic papillary type and the BRAF(V600E) mutation is highly prevalent. AIM: To evaluate the role of pre-operative detection of BRAF(V600E) mutation in the FNAB specimens of thyroid nodules in a BRAF(V600E) mutation-prevalent geographical area. PATIENTS AND METHODS: In 137 specimens of FNAB (107 papillary thyroid carcinomas (PTC); 3 follicular thyroid carcinomas (FTC); 2 undifferentiated thyroid carcinomas; 25 benign lesions), both direct DNA sequencing and PCR-RFLP were used for detecting the BRAF(V600E) mutation. The sensitivity and specificity were calculated. We analysed the association between BRAF(V600E) mutation and the clinico-pathological parameters. RESULTS: The BRAF(V600E) mutation was present in 93 (83%) of 112 thyroid cancers. Direct DNA sequencing showed a sensitivity of 83.0% and a specificity of 96.0%. The sensitivity and specificity of PCR-RFLP were 78.6% and 80.0%, respectively. Among 25 cases with indeterminate FNAB cytology, 8 patients had malignant lesions (5 PTC and 3 FTC). Three (60%) of 5 PTCs and 1 out of 17 benign lesions had BRAF(V600E) mutation (only one false positive case and the definitive pathology showed atypical nodular hyperplasia that could be a premalignant lesion). The diagnostic accuracy of this molecular method in only the 25 indeterminate nodules was 76% (19/25). No mutation was found in 3 FTCs. Among 107 PTCs, there was no significant association of the BRAF(V600E) mutation with the known risk factors. CONCLUSION: Detection of the BRAF(V600E) mutation in FNAB specimens refines the FNAB-cytology diagnosis, especially in a BRAF(V600E) mutation-prevalent area. Direct DNA sequencing was a more reliable method than PCR-RFLP for detecting the BRAF(V600E) mutation with a high sensitivity and specificity.

The melanoma antigen gene as a surveillance marker for the detection of circulating tumor cells in patients with breast carcinoma.

BACKGROUND: Circulating occult tumors cells could be used for the surveillance of metastases after primary breast carcinoma therapy, but their detection is limited by the lack of specific molecular markers. Melanoma antigen genes (MAGEs), which are expressed in malignant tissues but not in normal tissues (except for placenta and testis), might provide such a marker. To date, however, the use of MAGEs in the detection of occult tumor cells using reverse transcription-polymerase chain reaction (RT-PCR) has been limited because of the heterogeneity and low expression of individual MAGEs in tumor tissues. METHODS: We developed multiple MAGE-recognizing primers (MMRPs) that were capable of binding to the cyclic DNA of 6 MAGE-A gene subtypes (MAGE-A1-MAGE-A6). We assessed the ability of the MMRPs to detect the expression of MAGE-A gene subtypes in peripheral blood obtained from patients with benign or malignant breast disease. RESULTS: MAGE-A gene expression was not detected in 32 patients with benign disease but was detected in 1 of 31 patients (3%) patients with negative lymph node breast carcinoma, in 10 of 52 patients (19%) with 1-3 positive lymph nodes, in 11 of 53 patients (21%) with > or = 4 positive lymph nodes, and in 20 of 52 patients (39%) with metastatic disease. The results were statistically significant (P < 0.0001; chi-square test for linear-by-linear association). The results also showed that the detection of MAGE-A gene expression in the blood predicted tumor progression or recurrence. CONCLUSIONS: The results suggested that MAGE-A gene expression may be used for the surveillance of circulating breast carcinoma cells after primary therapy by RT-nested PCR using MMRPs.