Antitumor activity of the novel multi-kinase inhibitor EC-70124 in triple negative breast cancer

Disseminated triple negative breast cancer (TNBC) is an incurable disease with limited therapeutic options beyond chemotherapy. Therefore, identification of druggable vulnerabilities is an important aim. Protein kinases play a central role in cancer and particularly in TNBC. They are involved in many oncogenic functions including migration, proliferation, genetic stability or maintenance of stem-cell like properties. In this article we describe a novel multi-kinase inhibitor with antitumor activity in this cancer subtype. EC-70124 is a hybrid indolocarbazole analog obtained by combinatorial biosynthesis of Rebeccamycin and Staurosporine genes that showed antiproliferative effect and in vivo antitumoral activity. Biochemical experiments demonstrated the inhibition of the PI3K/mTOR and JAK/STAT pathways. EC-70124 mediated DNA damage leading to cell cycle arrest at the G2/M phase. Pathway analyses identified several deregulated functions including cell proliferation, migration, DNA damage, regulation of stem cell differentiation and reversion of the epithelial-mesenchymal transition (EMT) phenotype, among others. Combination studies showed a synergistic interaction of EC-70124 with docetaxel, and an enhanced activity in vivo. Furthermore, EC-70124 had a good pharmacokinetic profile. In conclusion these experiments demonstrate the antitumor activity of EC-70124 in TNBC paving the way for the future clinical development of this drug alone or in combination with chemotherapy.     

三阴性乳腺癌X线特征分析

目的:探讨三阴性乳腺癌的X线特征。方法:收集经手术病理证实为乳腺癌的202例患者资料,根据雌激素受体（ER）、孕激素受体（PR）和人表皮生长因子受体（HER-2）表达情况将其分为三阴性乳腺癌（TNBC）与非三阴性乳腺癌（NTNBC）,比较两组病例腺体分型、病灶是否单发、肿块情况及有无钙化。结果:202例乳腺癌TNBC有34例,NTNBC有168例。两组病例肿块边缘及有无钙化差异有统计学意义(P均＜0.05)。腺体分型、是否单发、肿块的大小、肿块的形态、肿块的密度差异无统计学意义。结论:TNBC有一定特征,大多为单发肿块,与NTNBC相比肿块边缘更易表现为清晰光滑,钙化相对少见的征象。     

ERK信号通路参与RANKL诱导的乳腺癌细胞迁移

目的：探讨细胞外调节蛋白激酶（ERK）信号通路在RANKL诱导的乳腺癌细胞迁移中的作用.方法：流式细胞术检测MDA-MB-231细胞表面RANK蛋白的表达;western-blot检测RANKL刺激后磷酸化ERK（P-ERK）及ERK的表达;Transwell法测定RANKL刺激后细胞迁移能力的改变.结果：MDA-MB-231细胞表达RANK蛋白,RANKL诱导MDA-MB-231细胞迁移能力增强.RANKL刺激后MDA-MB-231细胞P-ERK表达升高,PD98059抑制RANKL诱导的细胞迁移.结论：ERK信号通路参与RANKL诱导的乳腺癌细胞迁移.     

三阴性乳腺癌及其研究进展

三阴性（雌激素、孕激素受体与HER-2均为阴性）乳腺癌是具有特殊生物学行为及临床病理特征的一个乳腺癌亚型,与基底样乳腺癌和BRCA1相关性乳腺癌有一定相关性。此类型乳腺癌对放化疗尚比较敏感,但常规标准治疗疗效欠佳,预后较其他类型乳腺癌差。目前针对其BRCA1、EGFR等基因及其功能异常而开展的相应研究正在进行。     

西达本胺对三阴性乳腺癌细胞凋亡和侵袭的影响

目的 探讨组蛋白去乙酰化酶抑制剂（HDACi）西达本胺对三阴性乳腺癌细胞株CAL 51体外增殖、凋亡及侵袭的作用。方法 采用实时无标记细胞分析（RTCA）技术检测不同浓度西达本胺（0、5、10、20、50、100μmol／L）对CAL 51细胞的增殖抑制作用;倒置显微镜下观察西达本胺（10、15、20μmol／L）处理CAL 51细胞72h后的细胞形态;流式细胞仪检测细胞周期、凋亡及乳腺癌干细胞比例;采用RTCA技术检测西达本胺对细胞侵袭、浸润能力的影响。结果 西达本胺在体外能明显抑制CAL 51细胞的增殖,且与药物浓度呈正相关（r=0.791,P＜0.001）;细胞形态发生改变;流式细胞仪检测显示细胞出现明显凋亡,且随药物浓度、作用时间的增加而升高（P＜0.05）,细胞周期和干细胞比例无变化;西达本胺对CAL-51细胞的侵袭、浸润能力有抑制作用,且随着药物浓度的增加,细胞侵袭能力明显降低（P＜0.05）。结论 西达本胺能够明显抑制CAL-51细胞的生长,诱导其凋亡,并降低其侵袭、浸润能力。     

铂类药物用于三阴性乳腺癌的新辅助化疗

三阴性乳腺癌(triple-negative breast cancer,TNBC)作为乳腺癌的一个亚型,其复发率较高而总生存率低。尽管其对于包含蒽环类和紫衫类药物为基础的新辅助化疗方案反应显著,但预后较差。目前尚未发现专门的分子及化疗药物作用靶点。铂类并非是治疗三阴性乳腺癌的常规用药,本文对铂药物用于三阴性乳腺癌新辅助化疗的现状进行综述。     

三阴性乳腺癌分子靶向治疗的研究进展

三阴性乳腺癌(TNBC)是雌激素受体(ER)、孕激素受体(PR)和人表皮生长因子受体2(HER-2)均阴性的乳腺癌,具有独特的病理和分子生物学特性,表现为复发早、进展快、生存期短和预后较其他类型乳腺癌差的特点。除手术治疗外,化疗是其主要的全身治疗手段。目前靶向治疗正逐步应用于乳腺癌的临床治疗中,对TNBC靶向治疗的深入研究,将有助于临床采取有效的治疗方法以提高其疗效。     

三阴性乳腺癌易患因素的研究进展

三阴性乳腺癌（Triple negative breast cancer,TNBC）是乳腺癌的一种特殊亚型,包括基底样型乳腺癌和未分类型乳腺癌。自从2005年被定义,TNBC在生物学特性上与其他亚型的差异、不良的预后情况就一直是流行病学家,病理学家及临床医生研究的重点与热点。 TNBC的易患因素包括种族、肥胖、年龄、女性生殖期口服避孕药、体育锻炼、流产史、家族史和社会经济因素等。本文主要就种族、肥胖、女性生殖期口服避孕药和年龄对三阴性乳腺癌的影响的最新研究成果进行综述,旨在加强健康女性对三阴性乳腺癌的认识与自我保健,提示临床医生将TNBC生物学特点与流行病学特点结合进行指导预防,为研究人员对TNBC的病因学进一步的研究提供更多的理论依据。     

RNAi‐mediated downregulation of uPAR synergizes with targeting of HER2 through the ERK pathway in breast cancer cells

Overexpression of urokinase plasminogen activator receptor (uPAR) or HER2 (erbB‐2) in breast cancer is associated with a poor prognosis. We previously reported that gene amplification and overexpression of HER2 and uPAR occur in 70% of HER2‐amplified tumor cells from blood or tissue of patients with breast cancer. In this study, we first examined whether depletion of HER2 and uPAR synergized in suppression of the growth of breast cancer cells that overexpress both HER2 and uPAR (SKBR3 and ZR 751). The results showed that depletion of either HER2 or uPAR by RNA interference suppressed cell growth and induced cell apoptosis, but that these effects were significantly enhanced in cells depleted of both HER2 and uPAR. Mechanistic analysis demonstrated that silencing of HER2 and uPAR caused suppression of MAPK signal pathways, resulting in decrease of ERK activity and prompting a high p38/ERK activity ratio. The level of the phosphorylated form of ERK was decreased in cells depleted of HER2, uPAR or both, and the effect in cells depleted of both is the most evident. Moreover, downregulation of uPAR synergized with trastuzumab to suppress the growth and induce apoptosis of SKBR3 and ZR 751 cells. uPAR RNAi significantly enhanced the effect of trastuzumab on inhibition of MAPK signal pathways. In conclusion, targeting HER2 and uPAR has a synergistic inhibitory effect on breast cancer cells. Our results provide evidence that simultaneous downregulation of HER2 and uPAR may offer an effective tool for breast cancer therapy.     

Exploratory comparisons between different anti-mitotics in clinically-used drug combination in triple negative breast cancer

Triple-negative breast cancer (TNBC) constitutes a very aggressive type of breast cancer with few options of cytotoxic chemotherapy available for them. A chemotherapy regimen comprising of doxorubicin hydrochloride and cyclophosphamide, followed by paclitaxel, known as AC-T, is approved for usage as an adjuvant treatment for this type of breast cancer. In this study we aimed to elucidate the role of KIF11 in TNBC progression throughout its inhibition by two synthetic small molecules containing the DHPM core (dihydropyrimidin-2(1H)-ones or -thiones), with the hypothesis that these inhibitors could be an interesting option of antimitotic drug used alone or as adjuvant therapy in association with AC. For this purpose, we evaluated the efficacy of DHPMs used as monotherapy or in combination with doxorubicin and cyclophosphamide, in Balbc-nude mice bearing breast cancer induced by MDA-MB-231, having AC-T as positive control. Our data provide extensive evidence to demonstrate that KIF11 inhibitors showed pronounced antitumor activity, acting in key points of tumorigenesis and cancer progression in in vivo xenograft model of triple negative breast cancer, like down-regulation of KIF11 and ALDH1-A1. Moreover, they didn’t show the classic peripheral neuropathy characterized by impaired mobility, as it is common with paclitaxel use. These results suggest that the use of a MAP inhibitor in breast cancer regimen treatment could be a promising strategy to keep antitumoral activity reducing the side effects.     

Fatty acid binding protein 5 promotes metastatic potential of triple negative breast cancer cells through enhancing epidermal growth factor receptor stability

Fatty acid binding protein 5 (FABP5), an intracellular lipid binding protein, has been shown to play a role in various cancers, including breast cancer. However, FABP5 and its role in triple negative breast cancer (TNBC) have not been studied. We show FABP5 protein expression correlates with TNBC, high grade tumors, and worse disease-free survival in a tissue microarray containing 423 breast cancer patient samples. High FABP5 expression significantly correlates with epidermal growth factor receptor (EGFR) expression in these samples. Decreased tumor growth and lung metastasis were observed in FABP5^−/− mice othotopically injected with murine breast cancer cells. FABP5 loss in TNBC tumor cells inhibited motility and invasion. Mechanistic studies revealed that FABP5 knockdown in TNBC cells results in decreased EGFR expression and FABP5 is important for EGF-induced metastatic signaling. Loss of FABP5 leads to proteasomal targeting of EGFR. Our studies show that FABP5 has a role in both host and tumor cell during breast cancer progression. These findings suggest that FABP5 mediates its enhanced effect on TNBC metastasis, in part, through EGFR, by inhibiting EGFR proteasomal degradation. These studies show, for the first time, a correlation between FABP5 and EGFR in enhancing TNBC metastasis through a novel mechanism.     

A phase II clinical trial of weekly paclitaxel and carboplatin in combination with panitumumab in metastatic triple negative breast cancer

Purpose: Women with metastatic triple negative breast cancer (TNBC) can have a poor prognosis with treatment limited to cytotoxic chemotherapy. The identification of effective therapies that may limit exposure to cytotoxic chemotherapy and lead to prolonged survival is an unmet medical need. We tested an inhibitor of the epidermal growth factor receptor, panitumumab in combination with chemotherapy. Methods: We conducted a single arm clinical trial in women with metastatic or locally advanced TNBC to paclitaxel 80 mg/m2 and carboplatin AUC of 2 on days 1, 8, and 15 and panitumumab 6 mg/kg on days 1 and 15 for a cycle length of 28 days. The objectives were to evaluate the response rate and safety of the combination in comparison to historical controls. Results: Fourteen patients with TNBC were enrolled with a median age of 53 years. The majority of women were African American (64.3%) with visceral metastasis (64.2%). Hematologic toxicities, particularly neutropenia and thrombocytopenia, were a major cause of missed chemotherapy and delayed treatment in this study. The overall response rate (complete and partial response) of the 13 evaluable patients was 46%. The median time to best response was 2.4 months and the median time to disease progression was 3.6 months. We were able to perform the PAM50 analysis on tumors from 7 of our subjects. All the samples tested clustered within the basal-like subtype. Conclusions: In our experience the response rate of carboplatin, paclitaxel and panitumumab was consistent with other reports of response for cytotoxic chemotherapy in metastatic TNBC.     

三阴性乳腺癌放射治疗的研究进展

三阴性乳腺癌是乳腺癌的一个重要临床亚型,易复发、转移,预后较差。放射治疗是乳腺癌的有效局部治疗手段,可以降低局部复发风险。本文将从三阴性乳腺癌的生物学特征,保乳术后、改良根治术后放疗,放疗时机,放射增敏等方面的进展进行阐述,以期对三阴性乳腺癌预后的改善有所帮助。     

癌基因c-Src抑制剂对三阴性乳腺癌的疗效评价

目的：探讨癌基因C-Src抑制剂对三阴性乳腺癌的辅助治疗作用。方法体外培养三阴性乳腺癌细胞 MDA-MB-231,并与雌激素受体（ER）、孕激素受体（PR）阳性的乳腺癌细胞 T47D 以及HER2阳性的SK-Br-3细胞做比较。用癌基因 c-Src 抑制剂来治疗三株细胞。采用 MTT 和免疫电泳的方法检测细胞的生长以及细胞信号传导通路的改变。结果c-Src抑制剂可以部分抑制 T47D 细胞生长,对三阴性乳腺癌细胞 MDA-MB-231有很明显的抑制作用。但是,对 SK-Br-3细胞的生长没有阻滞作用。进一步研究发现,是否抑制细胞生长信号传导通路决定 c-Src 抑制剂的治疗效果。HER2抑制剂可以明显抑制 SK-Br-3细胞周期与生长,而对 MDA-MB-231没有效果。结论抑制癌基因c-Src酪氨酸激酶活性对三阴性乳腺癌细胞有很好的治疗效果。     

Rad51 supports triple negative breast cancer metastasis

In contrast to extensive studies on familial breast cancer, it is currently unclear whether defects in DNA double strand break (DSB) repair genes play a role in sporadic breast cancer development and progression. We performed analysis of immunohistochemistry in an independent cohort of 235 were sporadic breast tumours. This analysis suggested that RAD51 expression is increased during breast cancer progression and metastasis and an oncogenic role for RAD51 when deregulated. Subsequent knockdown of RAD51 repressed cancer cell migration in vitro and reduced primary tumor growth in a syngeneic mouse model in vivo. Loss of RAD51 also inhibited associated metastasis not only in syngeneic mice but human xenografts and changed the metastatic gene expression profile of cancer cells, consistent with inhibition of distant metastasis. This demonstrates for the first time a new function of RAD51 that may underlie the proclivity of patients with RAD51 overexpression to develop distant metastasis. RAD51 is a potential biomarker and attractive drug target for metastatic triple negative breast cancer, with the capability to extend the survival of patients, which is less than 6 months.     

Overview of recent advances in metastatic triple negative breast cancer

Metastatic triple negative breast cancer (TNBC) has an aggressive phenotype with a predilection for visceral organs and brain. Best responses to chemotherapy are predominately in the first line. Recent studies have demonstrated improved progression free survival with the combination of atezolizumab/pembrolizumab and chemotherapy in programmed death-ligand 1 positive metastatic TNBC. However, a recent trial in a similar population showed no benefit for atezoli-zumab and paclitaxel which led to a Food and Drug Administration alert. Two phase III trials (OLYMPIAD and BROCADE3) demonstrated a benefit in progression free survival (PFS) but not overall survival in patients with BRCA-associated metastatic TNBC treated with Olaparib or Talazoparib respectively. For those treated with Talazoparib, the time to deterioration in health related-quality of life was also longer compared to chemotherapy. The BROCADE3 trial demonstrated that the combination of a platinum and veliparib increased PFS in first-line metastatic TNBC but at the cost of increased toxicity. There are no head-to-head comparisons of a poly (adenosine diphosphate-ribose) polymerase inhibitors (PARPi) and platinums. There are unanswered questions regarding the role of PARPi maintenance after platinum therapy as is standard of care in BRCA-associated ovarian cancer. Other areas of therapeutic interest include targeting aberrations in the phosphoinositide 3-kinase pathway, protein kinase B, mammalian target of rapamycin or utilising antibody drug conjugates. This review focusses on recent and emerging therapeutic options in metastatic TNBC. We searched PubMed, clinicaltrials.gov and recent international meetings from American Society of Clinical Oncology, San Antonio Breast Cancer Conference and the European Society of Medical Oncology.     

三阴性乳腺癌治疗的研究进展

三阴性乳腺癌（triple negative breast cancer，TNBC）是雌激素受体(estrogen receptor，ER)、孕激素受体（progesterone receptor，PR）及人类表皮生长因子受体（human epidermal growth factor-2,HER-2）均不表达的乳腺癌。按其功能特征可归纳为5类分子分型:以DNA修复缺陷或生长因子为途径的基底细胞样三阴性乳腺癌；以上皮-间充质转化和肿瘤干细胞为特征的间质样三阴性乳腺癌；免疫调节型三阴性乳腺癌；雄激素受体过表达的管腔／分泌型三阴性乳腺癌；HER-2富集型三阴性乳腺癌。三阴性乳腺癌恶性程度高且异型性较大，其治疗困难且预后较差，内分泌治疗及靶向治疗不敏感。目前很多学者对于三阴性乳腺癌的治疗各有研究，并有临床试验证实下述治疗有效。     

ghrelin调控ERK信号通路对乳腺癌细胞多药耐药的影响及机制

目的:探讨ghrelin调控ERK信号传导通路对乳腺癌细胞多药耐药的影响及机制.方法:人乳腺癌细胞MDA-MB-231细胞培养,设立对照组、多柔比星组、gbrelin组、ghrelin联合多柔比星组、ghrelin联合多柔比星加PD098059抑制剂组,采用流式细胞法检测细胞凋亡,Western-blot方法检测细胞ERK、p-ERK、P-gp蛋白的表达.结果:在ghrelin干预下人乳腺癌MDA-MB-231细胞凋亡率最低(P＜0.01),在多柔比星的干预下人乳腺癌MDA-MB-231细胞凋亡率最高(P＜0.01),ghrelin联合多柔比星能够抑制多柔比星对人乳腺癌MDA-MB-231细胞的促凋亡作用(P＜0.01),ghrelin联合多柔比星加ERK信号通路特异性阻滞剂PD98059能够减弱ghrelin联合多柔比星对人乳腺癌MDA-MB-231细胞凋亡的抑制作用(P＜0.01).多柔比星组与ghrelin组相比ERK表达及p-ERK水平明显下降(P＜0.05)、且ghrelin组与多柔比星组相比P-gp蛋白表达明显上升(P＜0.05),ghrelin联合多柔比星组与多柔比星组相比ERK表达及p-ERK水平明显增加(P＜0.05)、且P-gp蛋白表达明显增加(P＜0.05),ghrelin联合多柔比星加抑制剂组与ghrelin联合多柔比星组相比ERK表达及p-ERK水平明显下降(P＜0.01),P-gp蛋白表达无显著性差异(P=0.07).结论:一定浓度的ghrelin激活乳腺癌细胞ERK信号通路增加P-gp蛋白表达,从而抑制多柔比星诱导乳腺癌细胞凋亡而诱发耐药的产生,阻断ghrelin-ERK信号通路可能逆转乳腺癌细胞多药耐药的发生.