Cx43对乳腺癌细胞侵袭和迁移及细胞间隙通讯的影响

目的:探讨Cx43对乳腺癌侵袭、迁移以及细胞间隙通讯功能的影响。方法:用脂质体转染法将Cx43质粒、Cx43 siRNA及阴性对照转染入人乳腺癌细胞株MDA-MB-231。细胞黏附实验、Transwell试验检测细胞黏附、侵袭和迁移能力。分子生物学方法检测MMP-2、MMP-9、BRMS-1的表达。荧光染料传输实验检测不同Cx43表达的细胞间隙通讯的功能。结果:细胞黏附实验结果表明相较于野生型细胞,Cx43 siRNA组黏附能力（0.43±0.07）降低（t=20.801,P=0.002）,Cx43质粒组黏附能力（1.63±0.26）增高（t=5.917,P=0.027）。Transwell实验表明相较野生组,Cx43质粒组侵出小室的细胞数增加（侵袭:1.25±0.04,t=16.339,P=0.004;迁移:1.33±0.02,t=22.770,P=0.002）,而Cx43 siRNA组侵出小室的细胞数减少（迁移:0.84±0.04,t=11.139,P=0.008;侵袭:0.79±0.04,t=5.743,P=0.029）。分子生物学检测发现Cx43质粒组MMP-2、MMP-9表达增高,BRMS-1表达降低,而Cx43 siRNA组MMP-2、MMP-9表达降低,BRMS-1表达增高。染料传输实验证实相较野生组传输能力,Cx43质粒组传输作用增强;Cx43 siRNA组细胞间的传输作用减弱。结论:Cx43对乳腺癌细胞侵袭及迁移能力存在正调控。这一调控能力可能通过GJIC实现。     

乳腺癌耐药蛋白在癌组织中的表达及临床意义

背景与目的:乳腺癌耐药蛋白(BCRP)是新发现的多药耐药相关的膜转运蛋白,了解耐药蛋白在乳腺癌组织中的表达,对乳腺癌患者的治疗是有重要意义。我们研究了BCRP在乳腺癌组织中的表达以及它在乳腺癌化疗指导中的潜在意义,评估其在判断乳腺癌化疗敏感性中的作用。方法:应用流式细胞术检测31例原发乳腺癌组织中BCRP的表达,并分析其与临床病理特征的关系及对预后的影响。结果:BCRP在乳腺癌组织中的表达(0.282581±0.183686)与正常对照组(0.03125±1.000905)比较差别有非常显著性(P<0.01)。乳腺癌组织BCRP与ER、PR、c-erb-B-2、EGFR阴阳性值均数的比较,以及腋淋巴结无转移、腋淋巴结转移组之间BCRP表达值差均无显著性。结论:BCRP在乳腺癌组织中具有一定的表达水平,是独立于ER、PR、c-erb-B-2、EGFR的细胞膜蛋白。BCRP高表达者采用表阿霉素为辅的联合化疗可取得满意结果。     

乳腺癌耐药蛋白的研究进展

乳腺癌耐药蛋白 (BCRP)是新近发现的一种肿瘤耐药相关蛋白 ,与P gp和多药耐药相关蛋白 (MRP)同属ABC转运蛋白超家族。本文对BCRP的发现、基因转染、结构特点、组织表达和临床意义等方面研究进展进行综述。     

乳腺癌耐药蛋白在乳腺癌组织中的表达及其与预后的关系

目的:研究乳腺癌耐药蛋白(BCRP)在乳腺癌组织中的表达,评估其在乳腺癌预后中的作用。方法:采用免疫组织化学方法(IHC)检测60例手术切除的乳腺癌组织中BCRP的表达,并分析其与临床病理特征的关系及对预后的影响。结果:①BCRP在乳腺癌组织中的阳性表达率为35%(21/60例);②腋淋巴结或激素受体阳性者BCRP表达水平显著高于腋淋巴结阴性者和激素受体阴性者(P<0.05),BCRP表达与年龄、月经状况、肿瘤大小和组织学分级均无关(P>0.05);③Kaplan-Meier生存分析结果表明BCRP表达与无病生存期显著相关(P<0.05),但和总生存期无关(P>0.05);④Cox单因素和多因素分析都显示肿瘤大小、淋巴结转移和雌激素受体(ER)与无病生存期和总生存期显著相关(P<0.05),另外孕激素受体与总生存期(P<0.05)显著相关。结论:BCRP在乳腺癌组织中具有一定的表达水平,与乳腺癌患者的无病生存期有关,而与总生存期无关。     

铁死亡在乳腺癌肿瘤耐药中的研究进展

摘 要：乳腺癌是女性最常见的恶性肿瘤,肿瘤耐药是制约乳腺癌临床疗效的瓶颈,克服其肿瘤耐药性是亟待解决的问题。铁死亡是一种新型以铁依赖性脂质活性氧堆积为特征的细胞死亡,在乳腺癌及其耐药中具有重要作用。全文对铁死亡在乳腺癌耐药中的作用及其研究进展进行综述。通过评估铁死亡诱导剂、抑制剂及调节铁死亡通路在肿瘤耐药中作用,期待针对铁死亡通路的生物治疗将来成为逆转肿瘤耐药的治疗策略,为乳腺癌患者带来福音。     

NFκB家族蛋白对乳腺癌细胞化疗药物敏感性的影响

目的 了解乳腺癌细胞系NFκB家族蛋白的表达及其与化疗耐药的关系。方法 用免疫印记法分别检测了14个乳腺癌细胞系的P65，P50及IκB—α的表达，同时对10个细胞系进行MTT药物敏感实验。结果 IκB—α主要在胞浆内表达，虽然P65和P50在胞浆、胞核均有表达，但无论在胞浆还是在胞核，P50的表达均占明显优势，其在胞核的表达高达63％。P50胞核表达阳性者IC50值明显高于胞核阴性者，差异有显著意义。结论 1)乳腺癌细胞核P50表达可能预示化疗耐药，故可作为判断预后的一个新指标；2)NFκB家族蛋白中，P50的表达在乳腺癌中更常见，且在化疗耐药性的产生中可能起着更重要的作用。     

miRNA在乳腺癌化疗耐药中的作用

总结近期国内外有关miRNA在乳腺癌化疗耐药中作用的研究进展。应用Pubmed和CNKI期刊全文数据库检索系统以“miRNA、乳腺癌和化疗耐药”为关键词,检索2000年1月至2012年10月有关在乳腺癌化疗耐药中作用的文献。从乳腺癌化疗耐药入手,阐述乳腺癌化疗耐药的特点、机制,并着重对miRNA在乳腺癌化疗耐药中的作用进行分析。miRNA通过多种途径参与乳腺癌的化疗耐药。本文具体综述了一些以不同机制参与肿瘤耐药的miRNA,及其具体参与耐药的途径。探讨了血清miRNA作为肿瘤标记物的潜在临床利用性。结论:深入研究血清miRNA在乳腺癌耐药中的作用和机制,必将为乳腺癌的靶向治疗掀起一个新的篇章。      

乳腺癌耐药蛋白ABCG2对胰腺癌SW1990细胞耐药性影响的实验

目的 探讨吉西他滨诱导胰腺癌细胞SW1990中ABCG2的表达及其与化疗耐药的关系。方法 胰腺癌细胞SW1990用DMEM培养液常规培养,用0.82 mg/ml吉西他滨作用SW1990细胞24、48和72 h后,使用流式细胞仪测其细胞凋亡率,Western blot检测ABCG2蛋白的表达,RT-PCR检测ABCG2 mRNA的表达,并且分析ABCG2表达水平与化疗耐药的关系。结果 0.82 mg/ml吉西他滨作用SW1990细胞24、48和72 h后,细胞凋亡率分别为（21.1±0.61）%、（13.4±2.17）%、（6.4±1.34）%,不同时间点两两相比P均<0.05。0.82 mg/ml吉西他滨作用SW1990细胞24、48、72 h后与对照组相比,ABCG2 mRNA分别上升了（2.21±0.11）倍、（3.30±0.08）倍和（4.72±0.12）倍,蛋白上升了（2.17±0.14）倍、（3.61±0.09）倍和（4.98±0.13）倍,且组间比较P均<0.05,有统计学意义。结论 吉西他滨能抑制胰腺癌细胞SW1990的增殖,但随着时间延长,药物抵抗逐渐增强,这可能与吉西他滨作用细胞后上调ABCG2的表达有关。     

乳腺癌耐药蛋白的研究进展

乳腺癌耐药蛋白(BVRP)是新近发现的一种肿瘤耐药相关蛋白．与P-gp和多药耐药相关蛋白(MRP)同属ABC转运蛋白超家族。本文对BCRP的发现、基因表达特征、与造血干细胞分化的关系、转运底物及其耐药逆转和临床意义等方面的研究进展进行综述。     

An increase in cancer stem cell population after primary systemic therapy is a poor prognostic factor in breast cancer

Background:

The cancer stem cell (CSC) hypothesis has important clinical implications for cancer therapeutics because of the proposed role of CSCs in chemoresistance. The aim of this study was to investigate changes in the CSC populations before and after primary systemic therapy (PST) and their prognostic role in human breast cancer.

Methods:

Paired samples (before and after PST) of breast cancer tissue were obtained from clinical stage II or III patients (n=92) undergoing PST with the regimen of doxorubicin plus docetaxel (AD) (n=50) or doxorubicin plus cyclophosphamide (AC) (n=42) and subsequent breast resection. The proportions of putative CSCs with CD44+/CD24− or aldehyde dehydrogenase 1+ (ALDH1+) phenotypes were determined by immunohistochemistry.

Results:

A higher proportion of CD44+/CD24− tumour cells and ALDH1 positivity in pre-chemotherapy tissue was correlated with higher histologic grade, oestrogen receptor (ER) negativity, high Ki-67 proliferation index and basal-like subtype of breast cancer. Aldehyde dehydrogenase 1 positivity in pre-chemotherapy biopsy was also associated with a higher rate of pathologic complete response following PST. In comparisons of putative CSC populations before and after PST, the proportions of CD44+/CD24− and ALDH1+ tumour cells were significantly increased after PST. The cases with increased CD44+/CD24− tumour cell populations after PST showed high Ki-67 proliferation index in post-chemotherapy specimens and those with increased ALDH1+ tumour cell population after PST were associated with ER negativity and p53 overexpression. Furthermore, cases showing such an increase had significantly shorter disease-free survival time than those with no change or a reduced number of CSCs, and the survival difference was most notable with regard to the changes of ALDH1+ tumour cell population in the patients who received AC regimen.

Conclusion:

The present study provides the clinical evidence that the putative CSCs in breast cancer are chemoresistant and are associated with tumour progression, emphasising the need for targeting of CSCs in the breast cancer therapeutics.     

Long noncoding RNA LINP1 acts as an oncogene and promotes chemoresistance in breast cancer

Recent studies have shown that long non-coding RNAs (lncRNAs) are involved in a number of biological processes; however, further study is still warranted to comprehensively reveal their functions. In this study, we showed that the lncRNA in non-homologous end joining (NHEJ) pathway 1 (LINP1) was related to breast cancer cell proliferation, metastasis and chemoresistance. Loss- and gain-of function studies were used to assess the role of LINP1 in promoting breast cancer progression. LINP1 knockdown mitigated breast cancer cell growth by inducing G1-phase cell cycle arrest and apoptosis. LINP1 also promoted breast cancer cell metastasis and influenced the expression of epithelial-mesenchymal transition-related markers. We identified p53 as a regulator of LINP1, and LINP1 overexpression could restore the metastatic effects of p53. Furthermore, LINP1 was upregulated in doxorubicin- and 5-fluorouracil-resistant cells and induced chemoresistance. We also observed that LINP1 enrichment played a critical functional role in chemoresistance by inhibiting chemotherapeutics-induced apoptosis. Moreover, LINP1 in tumors was associated with lower overall survival and disease-free survival. In conclusion, LINP1 may serve as a potential oncogene and chemoresistance-related regulator of breast cancer cells, suggesting that LINP1 might be a potent therapeutic target and might reduce chemoresistance in breast cancer.     

Fascin is involved in the chemotherapeutic resistance of breast cancer cells predominantly via the PI3K/Akt pathway

Background:

A major therapeutic challenge for breast cancer is the ability of cancer cells to evade killing of conventional chemotherapeutic agents. We have recently reported the actin-bundling protein (fascin) as a major regulator of breast cancer metastasis and survival.

Methods:

Survival of breast cancer patients that received chemotherapy and xenograft tumour model was used to assess the effect of chemotherapy on fascin-positive and -negative breast cancer cells. Molecular and cellular assays were used to gain in-depth understanding of the relationship between fascin and chemoresistance.

Results:

We showed a significant correlation between fascin expression and shorter survival in breast cancer patients who received chemotherapy. In xenograft experiments, fascin-positive cancer cells displayed significantly more resistance to chemotherapy-mediated apoptotic cell death than fascin-negative counterparts. This increased chemoresistance was at least partially mediated through PI3K/Akt signalling, and was paralleled by increased FAK phosphorylation, enhanced expression of the inhibitor of apoptosis proteins (XIAP and Livin) and suppression of the proapoptotic markers (caspase 9, caspase 3 and PARP).

Conclusions:

This is the first report to demonstrate fascin involvement in breast cancer chemotherapeutic resistance, supporting the development of fascin-targeting drugs for better treatment of chemoresistance breast cancer.     

The impact of bilateral breast cancer on the prognosis of breast cancer: a comparative study with unilateral breast cancer

BACKGROUND: The clinical significance of bilateral breast cancer is unclear and its influence on prognosis is controversial. We assessed the impact of synchronous and metachronous bilateral breast cancer on the prognosis compared with unilateral breast cancer. METHODS: Between January 1, 1960 and December 31, 2001, 1,214 women were treated for primary operable breast cancers. Thirteen (1.1%) had synchronous bilateral breast cancer; 33 (2.7%) had a metachronous contralateral breast cancer. We compared age at operation, menopausal status, clinical stage, tumor size and histology, lymph node status, hormone receptor status, and use of adjuvant chemotherapy or hormone therapy, and we analyzed the impact of these factors on recurrence and survival in the 46 patients with bilateral breast cancer and the 1,168 patients with unilateral breast cancer. RESULTS: The 5-and 10-year disease-free survival rates, respectively, were 65% and 65% in metachronous cases, 85.7% and 64.3% in synchronous cases, and 77.9% and 72.1% in unilateral cases. There was no significant difference in overall survival among the three groups. On multivariate analysis, metachronous bilaterality, tumor size, lymph node status and adjuvant hormone therapy were each independent risk factors for recurrence, whereas bilaterality of breast cancer did not influence overall survival. CONCLUSIONS: Our data suggest that metachronous bilateral breast cancer is associated with shorter disease-free survival than synchronous bilateral or unilateral breast cancer, although overall survival does not differ among the 3 groups. Patients with metachronous bilateral breast cancer should be followed particularly closely in order to detect recurrence early and maximize quality of life.     

Trends in the management of breast cancer

Responses of general surgeons to a questionnaire on breast cancer were analyzed to determine the current trends in the management of this disease. A 21-item questionnaire was mailed to members of the New Jersey Chapter of the American College of Surgeons in 1982 and the responses, received on noncoded, anonymous answer sheets, were analyzed for frequency distribution. These responses were compared to previously recorded responses to the same questions for 1971 and 1977. Seventy-six percent of the respondents in 1982 performed needle aspirations often or always, compared to 36% in 1971 and 80% in 1977. The use of routine mammography has increased from 16% in 1971 and 20% in 1977 to 38% in 1982. Modified radical mastectomy is now the most common type of procedure employed in the management of stage I breast cancer, with 89% of respondents in favor of this approach compared to 15% in 1971 and 60% in 1977. Fifty-nine percent of the respondents are not opposed to breast reconstruction following mastectomy versus 14% in 1971 and 49% in 1977. For patients with axillary nodes, chemotherapy with multiple agents was recommended by 76% of general surgeons in 1982, compared to 58% in 1977. These results indicate a continuing trend towards increasing use of needle aspiration and routine mammography for diagnosis and for employment of chemotherapy with multiple agents in the adjuvant treatment of patients with positive axillary nodes. Furthermore, modified radical mastectomy is the operation of choice for stage I cancer of the breast for increasing numbers of surgeons.     

乳腺癌临床研究新进展

新的理论、技术和药物的研究促进着乳腺癌的临床研究的发展。经典的乳腺癌早期发现的方法是自我检查法、临床体检和钼靶摄片三者相结合,乳管内视镜和乳腺导管灌洗液细胞学检查可作为有效的补充;前哨淋巴结活检技术可能使腑淋巴结阴性患者免除腑淋巴结清扫而不影响治疗效果;新的药物和方案可提高术前新辅助化疗的完全缓解率,以利于进一步手术;保乳手术已成为早期乳腺癌的外科治疗有效手段之一,但开展这项工作时除患者的临床病理因素外还应考虑到患者的社会、经济等因素。不难发现目前乳腺癌临床研究的趋势表现为在重视早期发现和全身治疗的同时缩小手术范围。     

Reduced apoptosis and proliferation and increased Bcl-2 in residual breast cancer following preoperative chemotherapy

Experimental laboratory data suggest that tumour growth is a balance between apoptosis and proliferation and that suppression of drug-induced apoptosis by oncogenes such as bcl-2 may be an important cause of intrinsic chemoresistance. The aims of this study were to assess the in vivo relationship of apoptosis to proliferation and Bcl-2 protein in human breast tumours both prior to chemotherapy and in the residual resistant cell population at the completion of treatment. We examined apoptotic index (AI), Ki67 and Bcl-2 protein expression in the tissue of 40 patients with operable breast cancer immediately before ECF preoperative chemotherapy, and in 20 of these patients with residual tumour, at the completion of treatment. There was a significant positive association between AI and Ki67 both before and after chemotherapy, and in their percentage change with treatment. In the residual specimens AI and Ki67 were significantly reduced compared with pre-treatment biopsies, while Bcl-2 expression showed a significant increase. No differences were seen in the pre-treatment levels of any of the variables measured between patients obtaining pathological complete response and those who did not, although numbers were small. These data suggest that apoptosis and proliferation are closely related in vivo. It is possible that the phenotype of reduced apoptosis and proliferation, and increased Bcl-2 may be associated with breast cancer cells resistant to cytotoxic chemotherapy, although this can only be proven by assessing larger numbers of patients in relation to pathological response.     

乳腺癌骨转移机制研究进展

乳腺癌是一种容易发生骨转移的女性常见恶性肿瘤。乳腺癌细胞的特异性、骨微环境及两者间相互作用是形成骨转移的共同因素。乳腺癌细胞表达的趋化因子受体、整合素、溶骨因子和成骨因子等使肿瘤细胞易于扩散到骨,而骨微环境可以为肿瘤细胞的生长提供丰富的生长因子和细胞因子。一旦乳腺癌细胞侵入骨质,肿瘤细胞分泌的因子就会作用于骨的外在结构和内在结构（如造血干细胞、T细胞、血小板、内皮细胞等）,使骨质破坏且分泌相关因子反作用于癌细胞,从而引起转移的级联反应和恶性循环形成。