Objective： To explore the role and underlying mechanism of circ_0000515 in the progression of breast cancer. Methods： The circRNAs chip dataset (GSE101123) of breast cancer was downloaded from GEO database and analyzed by R language. The target circRNA was selected and its expression in breast cancer cell lines and tissues were detected. The target miRNA of the circRNA and the target mRNA of the miRNA were selected by bioinformatics analysis, and verified by double luciferase experiment and Western blotting. The siRNA of circRNA was transfected into MCF-7 and MDA-MB-231. The cell proliferation and migration were measured by CCK-8 and scratch assay. The expression of RNA were detected by qRT-PCR. The expression of mRNAs-encoded protein was detected by Western blotting. Results： GSE101123 dataset was selected and downloaded. Five highly expressed circRNAs molecules were screened by R language, and circ_0000515 was selected as the research object for subsequent study. Bioinformatics analysis showed that there may be a targeted relationship among circ_0000515, miR12965p and cell cycledependent kinase 2 (CDK2). qRT-PCR results showed that the expression of circ_0000515 in breast cancer cell lines was higher than that in normal cell lines, and its expression in cancer tissues was higher than that in paracancerous tissues. After knockdown the expression of circ_0000515, the proliferation and migration ability of breast cancer cells decreased significantly, while the expression of miR-1296-5p increased. Double luciferase assay confirmed that there was a targeted relationship between circ_0000515 and miR-1296-5p. Western blotting showed that the expression of CDK2 decreased after knocking down the expression of circ_0000515. Conclusion： circ_0000515 is highly expressed in breast cancer. circ_0000515/miR-1296-5p/CDK2 axis may play a role in the progression of breast cancer.

 

Objective: To investigate the expression of leucinerich repeat protein 1 （LRR1） in breast cancer cells and its effect on cells biological function. Methods: Human breast cancer MDA-MB-231, HCC70 cell lines and normal breast epithelial MCF-10A cells were cultured; Western blotting was used to detect the expression of LRR1. Human breast cancer MDA-MB-231 and HCC70 cell lines were divided into interference control group, LRR1 interference group, LRR1 overexpression group and empty vector control group, which were transfected with LRR1 control, interference, overexpression and empty vector sequences, respectively; Transwell assay was used to detect migration and invasion ability of breast cancer cells; Western blotting was used to detect the expression of mammalian target of rapamycin （mTOR）. Results: Compared with normal human breast epithelial MCF-10A cells, the expression level of LRR1 in breast cancer MDF-MB-231 and HCC70 cells was significantly increased （both P<0.01）. In human breast cancer MDA-MB-231, HCC70 cell line, compared with the interference control group, LRR1 interference group significantly decreased the number of cell migration and invasion （all P<0.01）, and the expression level of m-TOR was significantly decreased（both P<0.01）; compared with the empty vector control group, LRR1 overexpression group significantly increased the numbers of migration and invasion（both P<0.01）, and the expression level of m-TOR protein was significantly increased （both P<0.01）. Conclusion: LRR1 is highly expressed in breast cancer cell lines and promotes their migration and invasion.
［Key words］breast cancer; leucinerich repeat protein 1; mammalian target of rapamycin（m-TOR）; cell migration; cell invasion

Objective: To analyze the prognostic factors of breast cancer-specific and non-breast cancer-specific deaths in elderly female breast cancer patients, using a competing risk model based on the SEER database. Methods: Female breast cancer patients aged ≥70 years were selected from 2006 to 2010 in the SEER database, and the “cmprsk” package in the R statistical software was used to perform univariate and multivariate analysis of the competing risk model. Results: A total of 31 823 elderly patients were included in the study, and 13 075 died during follow-up. Among them, 3 735 died from breast cancer, and 9 340 died from non-breast cancer causes. The 1-, 3-, and 5-year breast cancer-specific mortality rates were 1.47%, 5.39% and 8.71%, respectively; and the non-breast cancer mortality rates were 2.17%, 8.49% and 15.79%, respectively. The results of multivariate analysis showed that advanced age, single status, black race, estrogen receptor positivity, poorly differentiated, advanced T and N stages and no radiotherapy were independent poor prognostic factors affecting the cause of breast cancer death in elderly patients; advanced age, single status, estrogen receptor positivity, advanced T stage and other factors were independent poor prognostic factors affecting non-breast cancer death in elderly patients. Conclusion: Elderly breast cancer patients are more likely to die from non-breast cancer than from breast cancer, and their radiotherapy could reduce breast cancer-specific and non-specific breast cancer deaths.
［Key words］elderly; breast cancer; SEER database; estrogen receptor; competing risk model; prognostic factors

Objective:To investigate the effect and mechanism of Andrographolide (Andro) on the metastasis and invasion of human breast cancer MDA-MB-231 cells. Methods: MDA-MB-231 cells were treated with Andro(0,5,10, 20,40 and 80 μmol/L)for 24 h. MTT assay was used to detect cell proliferation.Wound healing and Transwell experiment were applied to detect cell migration and invasion ability.Reverse transcription polymerase chain reaction were applied to detect uncoupling protein 2 (UCP2) mRNA expression.The protein expressions of UCP2 and pyruvate dehydrogenase (PDH) were detected by Western blotting. Lactic acid kit was used to detect lactic acid content. JC-1 staining and laser confocal microscope were used to detect mitochondrial membrane potential (MMP). Results: Compared with the control group, Andro significantly inhibited the proliferation of MDA-MB-231 cells in a concentration-dependent manner. Compared with 0 μmol/L, the metastasis and invasion of MDA-MB-231 cells in the 10, 20, and 40 μmol/L groups were inhibited (P<0.05 or P<0.01); UCP2 mRNA and protein expression were downregulated (P<0.05 or P<0.01), MMP was increased, PDH protein expression was up-regulated, and intracellular lactate content was decreased (P<0.05 or P<0.01). Conclusion: Andro may inhibit the metastasis and invasion of MDA-MB-231 cells by inhibiting the glycolysis of breast cancer cells and altering energy metabolism, which may be related to inhibition of UCP2.

Objective: To develop novel polydopamine composite nanoparticles and explore its combined inhibition of breast cancer cells. Methods: Novel polydopamine nanoparticles -AIPH@PB NPs） were prepared by one-step oxidation polymerization using serum albumin（BSA）, 2,2-azobis［2（2imidazoline2yl）-propane- dihydrochloride （AIPH） and dopamine （DA） as precursors. The physical and chemical properties were characterized by Malvern particle size analyzer, Xray photoelectron spectroscopy（XPS） and Fourier infrared spectroscopy. Ultravioletvisible spectroscopy was used to characterize its ability to generate alkyl radicals. The photothermal conversion efficiency was characterized by near infrared thermal imager. The 4T1 breast cancer cells were used to verify the effect of tumor suppression in vitro. Results:  AIPH@PB NPs with good biocompatibility and a particle size of 165 nm were successfully prepared. Under the irradiation of 808 nm nearinfrared laser, AIPH@PB NPs could convert light energy into heat energy （photothermal conversion efficiency could be as high as 31%）. Meanwhile, local high temperature further induced the decomposition of AIPH to produce a large number of alkyl radicals. The cell experiment results showed that photothermal ablation and the generation of alkyl radicals mediated by AIPH@PB NPs significantly reduced the activity of 4T1 cells. Conclusion:  AIPH@PB NPs was successfully prepared and may， with strong photothermal conversion efficiency and highefficiency alkyl radical generation capacity, be used for combined inhibition of breast cancer cells.

Objective: To investigate the effect of acetyl-CoA synthase 2-（ACSS2） on proliferation and apoptosis in triple-negative breast cancer MDAMB468 cell and its potential mechanism. Methods:The mRNA and protein expression of ACSS2 in normal breast epithelial cells MCF-10A and human triplenegative breast cancer MDA-MB-468 cell was detected by quantitative real-time PCR（qRT-PCR） and Western blotting， respectively. SiRNAs specific for ACSS2（siRNA-ACSS2） or a scrambled sequence（siRNA-NC） were designed and synthesized as positive and negative controls for transfection, respectively. SiRNAACSS2 or siRNA-NC was transiently transfected into triplenegative breast cancer MDA-MB-468 cells. The interference efficiency of ACSS2 were assessed by qRT-PCR and Western blotting. The proliferation capacity of MDA-MB-468 before and after conducting the targeted interference with ACSS2 was examined by CCK-8 assay. The apoptosis rate of MDA-MB-468 cells before and after interference was determined, using flow cytometry. Additionally, PI3K/AKT signaling pathway and the apoptosis-related proteins such as cleaved-caspase-3, Bcl-2, Bax and proliferation marker ki-67 were detected by Western blotting. Results: Compared with normal breast epithelial cells MCF-10A, MDA-MB-468 cells were showed with higher levels of the mRNA and protein expression of ACSS2（P<0.01）. Compared with MDA-MB-468 cells without the interference, targeted interference of ACSS2 strongly inhibited its proliferation and remarkably induced the apoptosis in MDA-MB-468 cells（all P<0.01）.  The protein expression levels of p-PI3K, p-Akt, Ki-67 and Bcl2 were significantly decreased （all P<0.01），meanwhile，the protein expression levels of cleaved-caspase-3 and Bax were marked increased （all P<0.01）.Conclusion: Interference with acetyl-CoA synthase 2 dramatically inhibit the proliferation of triple-negative breast cancer MDAMB468 cells and significantly promote the apoptosis of breast cancer cells, which may be through PI3K/AKT signaling pathway.

Objective: To investigate the expression level, biological function and molecular regulation mechanism of miR-376c3p in breast cancer cells.Methods: The expression level of miR-376c-3p in breast epithelial cell MCF-10A and breast cancer cells was detected by qRT-PCR, and then breast cancer cells MCF7 and MD-MB-231 were transfected with miR-376c-3p mimic.The proliferation was detected by colony formation assay.The migration and invasion were detected by Transwell assay and wound healing assay.Starbase database was used to predict the downstream target gene of miR-376c-3p, and the targeting relationship was verified by Western blotting.Results: Compared with human breast epithelial cell MCF-10A, the expression of miR-376C-3p was significantly down-regulated in breast cancer cells MCF-7 and MDA-MB-231（P<0.01）.Colony formation assay showed that overexpression of miR-376c-3p could inhibit the proliferation of breast cancer cells（all P<0.05）.Transwell assay and wound healing assay showed that the upregulation of miR-376c-3p inhibited the migration of breast cancer cells. Bioinformatics results showed that miR-376c-3p could bind to glutamate receptor interacting protein 1（GRIP1）, and Western blotting assay showed that miR-376c-3p could inhibit the expression of GRIP1 and vimentin, and increase E-cadherin expression in breast cancer cells.Conclusion: The expression of miR-376c-3p was down-regulated in breast cancer cells；overexpression of miR-376c-3p significantly inhibited the proliferation and migration ability of breast cancer cells in vitro, and miR376c3p may regulate the epithelialmesenchymal transition process of breast cancer by targeting GRIP1.

雌激素相关肿瘤是女性较为常见的恶性肿瘤类型。绝经前妇女雌激素主要由卵巢分泌，而绝经后雌激素的重要来源为芳香化酶催化雄激素转化为雌激素，因此芳香化酶抑制剂（aromatase inhibitors，AIs）作为绝经后乳腺癌、子宫内膜癌和上皮性卵巢癌的治疗药物在临床上得到广泛应用。AIs的使用会带来多种不良后果，如潮热、骨痛、骨质疏松和增加心血管疾病的风险等，但其引起的代谢失衡尤为重要。本文综述AIs治疗后可能带来的代谢失衡，分析代谢紊乱发生的原因，提出了采用联合使用二甲双胍和联合运动的方式改善AIs治疗雌激素相关肿瘤所致代谢失衡的新思路。