The diagnostic value of DNA repair gene in breast cancer metastasis.

Breast cancer is the most common malignant tumor in China and even in the world. DNA repair genes can lead to tumor metastasis by affecting cancer cell resistance. Studies have preliminarily shown that DNA repair genes are related to breast cancer metastasis, but it is not clear whether they can be used as a prediction of the risk of breast cancer metastasis. Therefore, this study mainly discusses the predictive value of DNA repair genes in postoperative metastasis of breast cancer. The nested case-control method was used in patients with breast cancer metastasis after surgery (n = 103) and patients without metastasis after surgery (n = 103). The proteins and mRNA of DNA repair genes were detected by immunohistochemistry and Real-time PCR respectively. In protein expression, PARP1 (OR 1.147, 95% CI 1.067 ~ 1.233, P < 0.05), XRCC4 (OR 1.088, 95% CI 1.015 ~ 1.166, P < 0.05), XRCC1 (OR 1.114, 95% CI 1.021 ~ 1.215, P < 0.05), ERCC1 (OR 1.068, 95% CI 1.000 ~ 1.141, P < 0.10) were risk factors for postoperative metastasis of breast cancer. In addition, we used the ROC curve to study the optimal critical values of MSH2, MLH1, PARP1, XRCC1, XRCC4, 53BP1, ERCC1 and XPA combined with the Youden index, and the effects of MSH2, MLH1, PARP1, XRCC1, XRCC4, 53BP1, ERCC1 and XPA on breast cancer metastasis were verified again. Among them, the risk of metastasis in the PARP1 high expression group was 3.286 times that of the low expression group (OR 3.286, 95% CI 2.013 ~ 5.364, P < 0.05). The risk of metastasis in the XRCC4 high expression group was 1.779 times that of the low expression group (OR 1.779, 95% CI 1.071 ~ 2.954, P < 0.05). The risk of metastasis in patients with ERCC1 high expression group was 2.012 times that of the low expression group (OR 2.012, 95% CI 1.056 ~ 3.836, P < 0.05). So we can conclude that protein expression of PARP1 (cut-off value = 6, Se = 76.70%, Sp = 79.61%), XRCC4 (cut-off value = 6, Se = 78.64%0, Se = 79.61%), ERCC1 (cut-off value = 3, Se = 89.32%, Sp = 50.49%), suggesting that when the PARP1 score is higher than 6 or the XRCC4 score is higher than 6 or the ERCC1 score is higher than 3, the risk of metastasis will increases. Due to PARP1, XRCC4 and ERCC1 belong to a part of DNA repair gene system, and the three proteins are positively correlated by correlation analysis (rPARP1-XRCC4 = 0.343; rPAPR1-ERCC1 = 0.335; rXRCC4-ERCC1 = 0.388). The combined diagnosis of the PARR1, XRCC4 and ERCC1 have greater predictive value for the risk of metastasis of breast cancer (Se = 94.17%, Sp = 75.73%; OR 11.739, 95% CI 2.858 ~ 40.220, P < 0.05). The postoperative metastasis of breast cancer could be effectively predicted when the immunohistochemical scores met PARP1 (IHC score) > 6, XRCC4 (IHC score) > 6 and ERCC1 (IHC score) > 3. In addition, the combined diagnosis of PARP1, XRCC4 and ERCC1 has great predictive value for the risk of breast cancer metastasis.

Random phase-shift Bragg grating-based random fiber laser with a half-open cavity.

A random fiber laser based on a 25 mm long random phase-shift fiber Bragg grating with a half-open cavity is experimentally demonstrated in this paper. The random phase-shift grating is fabricated in single-mode fiber with the beam-scanning method. The random feedback and light localization are achieved by introducing 20 phase shifts with random amplitudes along the grating length. Different couplers and different directions are adopted to investigate the output characteristics under multiple conditions. The stable single-wavelength laser operation with the pump threshold of only 25 mW is realized using a 980 nm pump laser. The optical signal-to-noise ratio up to 67 dB and the 3 dB bandwidth of 17.7 pm are obtained at the pump power of 350 mW. It is found that the emitted wavelength varies linearly with the surrounding refractive index within a certain range by immersing the grating in different concentrations of NaCl solutions, which provides a potential method for lasing wavelength tuning and refractive index detection.

Role of thyroid hormone homeostasis in obesity-prone and obesity-resistant mice fed a high-fat diet.

BACKGROUND: The exact mechanism for different propensities to obesity when consuming a high-fat diet (HFD) is largely unknown. Thyroid hormone (TH) is an important modulator of energy homeostasis and body weight. OBJECTIVE: The present study aimed to find the potential mechanisms of TH in the development of obesity-prone (OP) and obesity-resistant (OR) mice after short-term and long-term HFD feeding. METHODS: C57Bl/6 male mice were randomly divided into two groups: a low-fat diet (LFD) group and an HFD group. In the 7th week, HFD-fed mice were classified as OP or OR according to upper and lower tertiles of body weight. Half of the mice were sacrificed at this time point and the remaining mice were kept on feeding and sacrificed in the 27th week. Indirect calorimetry was performed. At harvest, serum was used for ELISA assays and oxidative stress biomarkers determination. Tissues were dissected for deiodinases activity and relative mRNA expression determination, as well as antioxidant capacity evaluation. RESULTS: In the 7th week, OP mice showed a significant body weight gain, decreased energy expenditure (EE), normal circulating TH levels, and activated HPT axis, whereas OR mice had normal body weight and maintained T(3) levels only through enhancing hepatic D1 activity. In the 27th week, OR mice gained more body weight than LFD mice accompanied by an activation of HPT axis and decreased hepatic deiodination. Genes involved in TH production were down-regulated in OP mice and up-regulated in OR mice. Changes in deiodinases activity and thyroid function were related with redox status in specific tissues. Furthermore, OP mice had more serious hepatic steatosis than OR mice, with up-regulation of T(3) target genes (e.g. Srebp1c, Acc1, Fasn) involved in lipid synthesis and down-regulation of Pgc1α, Cyp7a1 and Cpt1α. CONCLUSIONS: HPT axis function and deiodinases activity might be involved in different propensities to obesity and the ability of OR mice to resist obesity was limited.