Expression of TRAIL and TRAIL death receptors in stage III non-small cell lung cancer tumors.

PURPOSE: Several in vitro studies have shown that non-small cell lung cancer (NSCLC) cell lines are sensitive to apoptosis induction by the recombinant human (rh) tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) death ligand, indicating that rhTRAIL might become an attractive molecule for treatment of NSCLCs. To investigate the therapeutic potential of rhTRAIL, the expression of TRAIL and its apoptosis-inducing receptors DR4 and DR5 was evaluated in tumors of stage III NSCLC patients. EXPERIMENTAL DESIGN: Before treatment, tumor biopsies from locally advanced NSCLC patients were obtained by bronchoscopy. DR4, DR5, and TRAIL expression were determined immunohistochemically in 87 tumors. Patients were randomized for treatment with 60 Gy radiotherapy with or without carboplatin as radiosensitizer. RESULTS: DR4, DR5, and TRAIL were expressed in 99%, 82%, and 91% of the tumors, respectively. Seventeen percent of the samples expressed only DR4 and no DR5. In NSCLCs with squamous cell differentiation, a typical staining pattern for DR4 and DR5 was observed. Cells from the basal layer were strongly positive, and the more mature cells were less positive or negative. An inverse staining pattern was observed for TRAIL. Poorly differentiated areas showed strong staining intensity for DR4, DR5, and TRAIL. DR5-positive staining was associated with increased risk of death (odds ratio, 5.76; 95% confidence interval, 1.04-31.93; P = 0.045). CONCLUSIONS: The majority of the locally irresectable stage III NSCLCs expressed at least one of the two death receptors for TRAIL. Therefore, these death receptors may provide a target for the use of rhTRAIL as a new adjunct in the treatment of stage III NSCLC.     

TRAIL and docosahexaenoic acid cooperate to induce HT-29 colon cancer cell death

The resistance of some cancer cells to TRAIL-induced apoptosis is a major obstacle in successful clinical application of this cytokine. Combination treatment with agents capable of sensitising the cells to TRAIL effects is beneficial for new cancer treatment strategies. Docosahexaenoic acid (DHA) is under intense investigation for its ability to affect cancer cell growth and apoptosis. We demonstrated a modulation of TRAIL-induced apoptosis of HT-29 human colon cancer cells by DHA on the molecular (pro-caspase-3, -8, Bid, PARP cleavage) and cellular (cell viability and adhesion) level. To conclude, TRAIL and DHA were shown to cooperate in the induction of colon cancer cell apoptosis.     

EMT in breast cancer stem cell generation

The concept of cancer stem cells (CSCs) has been proposed to explain the ability of single disseminated cancer cells to reconstitute tumours with heterogeneity similar to that of the primary tumour they arise from. Although this concept is now commonly accepted, the origin of these CSCs remains a source of debate. First proposed to arise through stem/progenitor cell transformation, CSCs might also or alternatively arise from differentiated cancer cells through epithelial to mesenchymal transition (EMT), an embryonic transdifferentiation process. Using breast carcinomas as a study model, I propose revisiting the role of EMT in generating CSCs and the debate on potential underlying mechanisms and biological significance.     

乳腺癌干细胞的研究进展

乳腺癌是女性中常见的恶性肿瘤,其高度的异质性使乳腺癌患者的临床表现、形态学特征以及分子生物学表型均呈现出明显的不一致性,给诊断和治疗带来了很大的困难.肿瘤干细胞具有自我更新能力并能产生异质性的特征,与肿瘤进展、耐药、复发、转移等关系密切.本文对近年乳腺癌干细胞的研究进展作一综述.     

TRAIL在乳腺癌组织中的表达

目的:研究肿瘤坏死因子相关凋亡诱导配体(TRAIL)在乳腺癌组织中的表达。方法:免疫组化法检测TRAIL在乳腺癌组织中的表达。结果:TRAIL在乳腺不典型增生和腺癌中的表达无统计学差异。TRAIL的阳性表达水平与乳腺癌组织的分化程度呈正相关,即分化程度愈高,TRAIL表达水平愈高。TRAIL在不同临床分期乳腺癌组织中的表达无统计学差异,与有无淋巴结转移无统计学差异。结论:本实验从凋亡调节因子方面支持了不典型增生为癌前病变的观点,TRAIL蛋白的表达可能与乳腺癌组织的恶性程度有关,与肿瘤的生物学行为无关。     

miR-3132 upregulates surface TRAIL to induce apoptotic cell death in cancer cells

TRAIL-based therapies are of significant clinical interest because of its unique ability to induce apoptosis in cancer cells while sparing normal and untransformed cells. This selective antitumor potential of the TRAIL pathway has been harnessed by development of therapeutics including recombinant (rh)TRAIL and TRAIL-receptor agonist antibodies such as mapatumumab and lexatumumab. While these TRAIL-based therapies have proven successful in preclinical studies and safe in early phase clinical trials, the limited serum half-life has been a hurdle for further clinical development. Here we characterize miR-3132, a novel and first-in class TRAIL-inducing miRNA with potent anti-proliferative and pro-apoptotic effects in cancer cell lines. Initial mechanistic studies indicate that miR-3132 engages the interferon signaling pathway to induce TRAIL and subsequent TRAIL-dependent apoptosis in cancer cell lines. Our data further suggests that the binding of miR-3132 to toll-like receptors could be the upstream pathway for the interferon response. The current study the first report to demonstrate miR-3132’s in vitro efficacy and preliminary mechanism of action in cancer cell lines.     

Separation of breast cancer stem cell and its heterogeneity

The successful separation of breast cancer stem cell (BCSC) is the foundation of BCSC research. At present, people could gather BCSC to some extent in a number of ways. However, as more and more biomarkers are found in BCSC separation, the heterogeneity becomes a hot spot. How to gather BCSC as much as possible and how to explain the heterogeneity could provide new insights in the treatment of breast cancer.     

乳腺癌干细胞分选及其异质性

乳腺癌干细胞的成功分选是进行乳腺癌干细胞研究的基础,目前人们可以通过多种方法使乳腺癌干细胞得到一定程度的富集.然而,在越来越多乳腺癌干细胞表面标志物被发现的同时,其异质性也成为人们关注的热点.如何最大程度地富集乳腺癌干细胞及解释其异质性,将为乳腺癌的干细胞治疗提供新思路.     

Insights into the cell of origin in breast cancer and breast cancer stem cells

The precise cell types that give rise to tumors and mechanisms that underpin tumor heterogeneity are poorly understood. There is increasing evidence to suggest that diverse solid tumors are hierarchically organized and may be sustained by a distinct subpopulation of cancer stem cells (CSCs). The CSC hypothesis provides an attractive cellular mechanism that can account for the therapeutic refractoriness and dormant behavior exhibited by many tumor types. Breast cancer was the first solid malignancy from which CSCs were identified and isolated. Direct evidence for the CSC hypothesis has also recently emerged from mouse models of mammary tumorigenesis, although alternative models to explain heterogeneity also seem to apply. Our group has found that the luminal epithelial progenitor marker CD61/β3 integrin identified a CSC population in mammary tumors from MMTV‐wnt‐1 mice. However, no CSCs could be identified in the more homogeneous MMTV‐neu/erbB2 model, suggesting an alternate (clonal evolution or stochastic) model of tumorigenesis. It seems likely that both paradigms of tumor propagation exist in human cancer. From a clinical perspective, the CSC concept has significant implications. Quiescent CSCs are thought to be more resistant to chemotherapy and targeted therapy. Enrichment of putative CSCs has been noted in studies of chemotherapy‐treated patients, lending support to the CSC hypothesis and their potential role in chemoresistance. Although many unresolved questions on CSCs remain, ongoing efforts to identify and characterize CSCs continue to be an important area of investigation, with the potential to identify novel tumor targeting strategies.     

新辅助化疗对乳腺癌细胞周期及干细胞的影响

目的：探讨新辅助化疗对乳腺癌患者细胞周期中 G0-G1期细胞比例以及三磷酸腺苷结合转运蛋白 G 超家族成员2（ABCG2）、CD44＋CD24－／low表达的影响。方法选取2013年5月至2014年3月收治的60例经空芯针穿刺活检明确病理诊断的初治乳腺浸润性导管癌患者为研究对象,比较化疗前后乳腺癌细胞周期中 G0-G1期细胞比例及 ABCG2、CD44＋CD24－／low 含量的变化。结果患者化疗后ABCG2为（25．10±1．50）％,CD44＋CD24－／low 为（36．40±3．80）／105,G0-G1期细胞比例为（70．50±1．50）％,均高于化疗前的（15．88±1．22）％、（25．00±3．40）／105、（60．65±1．30）％,差异具有统计学意义（t ＝8．685,P ＜0．05;t ＝9．226,P ＜0．05;t ＝8．898,P ＜0．05）。所有患者完成4个疗程的化疗后,cCR率、cPR 率、SD 率分别为18．3％（11／60）、73．3％（44／60）、8．3％（5／60）。结论新辅助化疗后患者肿瘤细胞发生周期阻滞,肿瘤干细胞比例上升,疗效确切,具有临床推广价值。     

Suppression of apoptosis inhibitor c-FLIP selectively eliminates breast cancer stem cell activity in response to the anti-cancer agent,TRAIL

Introduction  

It is postulated that breast cancer stem cells (bCSCs) mediate disease recurrence and drive formation of distant metastases - the principal cause of mortality in breast cancer patients. Therapeutic targeting of bCSCs, however, is hampered by their heterogeneity and resistance to existing therapeutics. In order to identify strategies to selectively remove bCSCs from breast cancers, irrespective of their clinical subtype, we sought an apoptosis mechanism that would target bCSCs yet would not kill normal cells. Suppression of the apoptosis inhibitor cellular FLICE-Like Inhibitory Protein (c-FLIP) partially sensitizes breast cancer cells to the anti-cancer agent Tumour Necrosis Factor-Related Apoptosis Inducing Ligand (TRAIL). Here we demonstrate in breast cancer cell lines that bCSCs are exquisitely sensitive to the de-repression of this pro-apoptotic pathway, resulting in a dramatic reduction in experimental metastases and the loss of bCSC self-renewal.     

Cancer stem cell heterogeneity in hereditary breast cancer

The cancer stem cell hypothesis proposes that tumors arise in stem or progenitor cells generating in tumors driven by a subcomponent that retains cancer stem cell properties. Recent evidence supports the hypothesis that the BRCA1 gene involved in hereditary breast cancer plays a role in breast stem cell function. Furthermore, studies using mouse BRCA1 knockout models provide evidence for the existence of heterogeneous cancer stem cell populations in tumors generated in these mice. Although these populations may arise from different stem/progenitor cells, they share the expression of a common set of stem cell regulatory genes and show similar characteristics in in vitro mammosphere assays and xenograft models. Furthermore, these 'cancer stem cells' display resistance to chemotherapeutic agents. These studies suggest that breast tumors may display intertumor stem cell heterogeneity. Despite this heterogeneity, cancer stem cells may share common characteristics that can be used for their identification and for therapeutic targeting.     

Cisplatin and etoposide in chemotherapy-refractory advanced breast cancer

Fourteen evaluable advanced breast cancer patients, extensively pretreated by chemotherapy, received a combination of cisplatin (DDP) and etoposide (VP 16). DDP was given at 60 or 100 mg/m2 on day 1, and VP 16 at 120 mg/m2 on days 1, 2 and 3; cycles were repeated every 4 weeks. Major responses were never obtained; a minor response in 1 patient, no change in 7 patients, and progression in 6 patients were observed. Main side effects were nausea and vomiting (62% severe), and leukopenia (31% leukocytes less than 2,000/mm3). Two patients refused further treatment due to intense nausea and vomiting. DDP-VP 16 combination chemotherapy is ineffective and poorly tolerated in heavily pretreated breast cancer patients.     

Histone deacetylase inhibitors induce cell death and enhance the susceptibility to ionizing radiation, etoposide, and TRAIL in medulloblastoma cells

Histone deacetylase inhibitors (HDIs) are a promising new class of antineoplastic agents with the ability to induce apoptosis and growth arrest of cancer cells. In addition, HDIs have been suggested to enhance the anticancer efficacy of other therapeutic regimens, such as ionizing radiation (IR) or chemotherapy. The objective of this study was to evaluate the activity of HDIs against medulloblastoma cells when applied either as single agents or in combination with IR, cytostatics, or TRAIL. The HDIs, suberoyl anilide hydroxamic acid (SAHA), sodium butyrate, and trichostatin A, were examined for their effects on the medulloblastoma cell lines, DAOY and UW228-2. We found that treatment with HDIs induced the dissipation of mitochondrial membrane potential, activation of caspase-9 and -3 and, consequently, apoptotic cell death. Moreover, all three HDIs significantly enhanced the cytotoxic effects of IR in DAOY cells. Likewise, treatment with SAHA markedly augmented the cytotoxicity of etoposide, while it had no effect on vincristine-mediated cell death. HDIs also potently increased the killing efficiency of TRAIL. TRAIL-induced, but not SAHA-induced, cell killing could be prevented by the caspase-8 inhibitor, z-IEDT-fmk. We conclude that HDIs may be useful for the treatment of medulloblastoma as monotherapy and particularly when given in combination with IR, appropriate cytostatics, or TRAIL.     

乳腺癌化疗耐药中肿瘤干细胞的作用及其机制

目的:了解肿瘤干细胞在乳腺癌化疗耐药中的作用及其相关机制的研究进展。方法:应用检索Pubmed及CNKI数据库检索系统,以肿瘤、干细胞、乳腺癌、化疗和耐药等为关键词,检索1999-01-2011-05的相关文献,纳入标准:肿瘤干细胞与乳腺癌化疗耐药。根据纳入标准分析42篇文献。结果:肿瘤干细胞是导致乳腺癌化疗耐药和治疗失败的主要细胞,其耐药的机制包括ATP结合盒转运子的过度表达、细胞解毒酶的过度活化、细胞存活和凋亡相关信号转导通路的异常激活、肿瘤壁龛对肿瘤干细胞的保护作用以及大部分肿瘤干细胞处于静止期。通过对这些耐药机制的干预,可以逆转肿瘤干细胞的耐药性。结论:肿瘤干细胞是导致乳腺癌化疗耐药的关键细胞,对其耐药机制的研究有助于展开针对肿瘤干细胞的靶向治疗,改善患者的预后。     

乳腺癌干细胞信号转导通路及以其为靶点的干细胞治疗

20世纪以来,乳腺癌的发病率在世界范围内呈逐年上升趋势,且发病年龄日趋年轻化.据估计,2009年美国有192 370名女性被诊断患有乳腺癌,40 170名女性因乳腺癌而死亡.在我国,乳腺癌亦位居女性恶性肿瘤发病率首位.