Minimal residual disease in hematopoietic malignancy: Technical approaches and clinical significance

New technology continues to provide methods to refine the definition of complete remission in patients with hematopoietic malignancy. Recent evidence indicates that quantitation of residual tumor burden over time may identify gradual increases indicative of potential relapse. It is the general hope that this increased sensitivity for identification of patients with residual tumor burden will allow for a more effective selection of therapeutic alternatives for these patients.In order to accurately assess whether lowering the threshold for definition of remission improves the clinical outcome of patients with MRD, future studies must include several important parameters. Effective clinical studies will require large groups of patients meeting carefully designed diagnostic criteria with strictly controlled, homogenous treatment protocols. In addition, they must utilize a multidisciplinary technical approach for the detection of MRD in order to properly assess the ability of each technology to measure clinically significant parameters. The choice of the most effective technologies and when to test the patient will be identified only through these carefully planned clinical trials. Additional considerations of cost and availability must then enter into utilization decisions as important financial considerations to be weighed against clinical significance.     

Ectopic expression of N-cadherin perturbs histogenesis in Xenopus embryos

Xenopus embryos express N-cadherin in a pattern similar to that observed in other species, and cells expressing Xenopus N-cadherin can bind to cells expressing chicken N-cadherin in vitro. To investigate the developmental role of this molecule, we injected mRNA encoding chicken N-cadherin into one blastomere of 2-cell-stage Xenopus embryos and examined the effect of its expression on their development. The ectopic expression of N-cadherin occurred in various regions of the injected embryos and induced abnormal histogenesis, such as thickening, clumping or fusion of cell layers. These results suggest that the precise quantitative and qualitative regulation of the expression of cadherins is essential to embryonic morphogenesis.     

Clinical significance of ALDH1A1 expression and its association with E-cadherin and N-cadherin in resected large cell neuroendocrine carcinoma

BackgroundThe roles of cancer stem cells (CSCs) and epithelial-mesenchymal transition (EMT) in solid tumors are well established. However, the interaction between CSCs and EMT in pulmonary large cell neuroendocrine carcinoma (LCNEC) remains unknown. The aim of this study was to investigate the expression and clinical significance of a CSC marker (ALDH1A1) and its correlation with Epithelial-like phenotype marker (E-cadherin) and Mesenchymal-like phenotype marker (N-cadherin) in LCNEC patients.MethodsImmunohistochemistry (IHC) for ALDH1A1, E-cadherin and N-cadherin expression was conducted on tissue microarrays made from 79 resected LCNEC patient samples. ALDH1A1 protein expression was evaluated by the IHC score, and its correlations with the expression of E-cadherin, N-cadherin and clinicopathological features were determined based on IHC data. Survival analyses were also performed.ResultsALDH1A1 was positively expressed in 75.9% (60/79 cases) of LCNEC patients. No significant difference in clinicopathological variables was observed between the ALDH1A1-negative and ALDH1A1-positive groups. However, ALDH1A1 expression was positively correlated with E-cadherin (Spearman's rho = 0.229, p-value = 0.007), which represents the epithelial-like phenotype, but not with N-cadherin. Patients with expression of ALDH1A1 had significantly longer disease-free survival (DFS) and overall survival (OS) than those who were ALDH1A1 negative (median DFS: 52 vs 12 months, p = 0.028; median OS: not reached; p = 0.027). Multivariate analysis showed that ALDH1A1 was an independent favorable prognostic factor for DFS (p = 0.032, HR: 0.438, 95% CI: 0.206–0.932) and OS (p = 0.025, HR: 0.279, 95% CI: 0.091–0.852) in LCNEC patients.ConclusionThis study suggests that ALDH1A1 can act as a favorable independent prognostic factor for LCNEC, which related to the epithelioid phenotype in EMT, and its internal mechanism needs further study.     

Purinergic receptor signaling regulates N-cadherin expression in primary astrocyte cultures

Extracellular ATP exerts both short-term and long-term effects in the CNS by stimulating cell-surface purinergic receptors. Here we have examined the effect of purinergic receptor activation on N-cadherin expression, a calcium-dependent cell adhesion molecule involved in many processes, including glia-glia and axon-glia interactions. When primary cultures of rat cortical astrocytes were treated with ATP, N-cadherin protein expression increased in a time- and concentration-dependent manner. In addition, ATP treatment caused an increase in N-cadherin immunoreactivity in both the cytoplasm and on the cell surface membrane. Interestingly, experiments with cycloheximide revealed that relocalization of N-cadherin to the cell surface membrane were independent of protein synthesis. The ATP-induced increase in N-cadherin protein expression was blocked by reactive blue 2 and 8-(p-sulfophenyl)-theophylline, suggesting involvement of both P2 and P1 purinergic receptors, respectively. In addition, N-cadherin expression was partially blocked when signaling from purinergic receptors to extracellular signal regulated protein kinase or Akt was inhibited by 1,4-diamino-2,3-dicyano-1,4-bis(2-aminophenylthio)butadiene or wortmannin, respectively. By using an in vitro model of traumatic CNS injury, we found that N-cadherin expression was increased when astrocytes were subjected to rapid and reversible mechanical strain. The findings presented here demonstrate a role for extracellular ATP, purinergic receptors and protein kinase signaling in regulating N-cadherin expression and suggest a role for this mechanism in cell-cell interactions.     

EGFR在晚期肺腺癌患者中的表达及临床意义

目的探讨表皮生长因子受体(EGFR)在晚期肺腺癌患者中的表达及其意义。方法收集60例晚期肺腺癌患者的胸腔积液及活检肺癌组织,采用免疫组化检测EGFR的表达,并探讨其表达与临床病理特征的关系。结果 EGFR在胸腔积液及肺癌组织中的阳性表达率分别为75.0%(45/60)、63.3%(38/60),两者差异无统计学意义(P0.05)。结论 EGFR均高表达于肺腺癌胸腔积液及腺癌组织,且与年龄、性别、吸烟史、分化程度及肿瘤的大小无明显相关,可指导肺腺癌患者的靶向治疗。     

EZH2在乳腺癌中的表达及其临床意义

目的 探讨EZH2在乳腺癌中的表达及其临床意义.方法 用免疫组化的方法研究105例乳腺癌中EZH2蛋白表达情况,并进一步探讨其与乳腺癌临床病理因素及其预后的关系.结果 EZH2蛋白在乳腺癌组织中表达明显高于乳腺良性疾病,其表达与患者年龄、肿瘤大小、TNM分期、PR和c-erbB-2表达无关(P＞0.05),与淋巴结转移、病理组织学分级、ER表达及乳腺癌预后相关(P＜0.05).EZH2蛋白表达在三阴性乳腺癌中表达明显高于非三阴性乳腺癌(P＜0.05).结论 EZH2在乳腺癌淋巴结转移及侵袭中扮演一定的角色,其与乳腺癌预后相关,与ER阴性的乳腺癌发生发展有关.     

分化抑制因子-1在大肠癌中的表达及临床意义

目的:研究分化抑制因子-1(Id-1)在人大肠癌组织中的表达及其与临床病理特征的关系。方法:应用免疫组织化学方法(SP法)检测Id-1在56例大肠癌组织及56例远癌肠黏膜中的表达水平,并分析其与临床病理特征的关系。结果:在大肠癌组织中Id-1的过表达率为80.4%,在远癌肠粘膜中过表达率为12.5%,两组比较差异有统计学意义(P0.01)。Id-1过表达与大肠癌Dukes分期及淋巴结转移有关(P0.05),而与患者年龄、性别、肿瘤组织分化程度无关(P0.05)。结论:Id-1过表达可能参与大肠癌演进,Id-1可作为判断大肠癌恶性程度和预后的指标。     

Somatostatin receptor gene expression in neuroblastoma

Somatostatin receptor expression is a favorable prognostic factor in human neuroblastoma. Somatostatin receptors have been demonstrated in vitro by pharmacologic analysis of tumor tissue and in vivo by diagnostic radioreceptor scintigraphy. However, which receptor subtypes (sst(1), sst(2), sst(3), sst(4), and sst(5)) are expressed in these tumors has not yet been delineated. We used RT-PCR to analyze expression of the five somatostatin receptor genes in 32 neuroblastoma tumor specimens. All 32 tumor specimens expressed mRNA for c-abl and sst(1); sst(2) mRNA was detected in 27/32 samples and somatostatin mRNA was detected in 30/32 tumor specimens. The remaining receptor subtypes, sst(3), sst(4), and sst(5) were variably expressed. Receptor protein for sst(1) and sst(2) was visualized in tumor neuroblasts as well as in endothelial cells of tumor vessels using immunostaining with specific anti-receptor antibodies. The effect of high expression of somatostatin receptors on cell proliferation was examined in SKNSH neuroblastoma cells transfected with sst(1) and sst(2). SS(14) binding to wild-type SKNSH cells was undetectable; but the native peptide bound with high affinity to the SKNSH/sst(1) and SKNSH/sst(2) neuroblastoma cell lines. Pharmacologic analysis of binding with two long-acting analogues, CH275 and octreotide, confirmed selective expression of sst(1) and sst(2) in stably transfected SKNSH cells. Formation of neuroblastoma xenograft tumors in nude mice was significantly delayed for both SKNSH/sst(1) (P<0.001) and SKNSH/sst(2) (P<0.05) cells compared to wild-type SKNSH. We conclude that: (1) Somatostatin receptors, sst(1) and sst(2), are expressed in the majority of neuroblastomas at diagnosis; and (2) upregulation of functional sst(1) or sst(2) in neuroblastoma cell lines suppresses tumorigenicity in a xenograft model. These observations suggest that somatostatin receptors may be a useful therapeutic target in neuroblastoma.     

Chromosomal protein HMGN1 modulates the expression of N-cadherin

HMGN1 is a nuclear protein that binds to nucleosomes and alters the accessibility of regulatory factors to their chromatin targets. To elucidate its biological function and identify specific HMGN1 target genes, we generated Hmgn1-/- mice. DNA microarray analysis of Hmgn1+/+ and Hmgn1-/- embryonic fibroblasts identified N-cadherin as a potential HMGN1 gene target. RT-PCR and western blot analysis confirmed a linkage between HMGN1 expression and N-cadherin levels. In both transformed and primary mouse embryonic fibroblasts (MEFs), HMGN1 acted as negative regulator of N-cadherin expression. Likewise, the N-cadherin levels in early embryos of Hmgn1-/- mice were higher than those of their Hmgn1+/+ littermates. Loss of HMGN1 increased the adhesiveness, motility and aggregation potential of Hmgn1-/- MEFs, a phenotype consistent with increased levels of N-cadherin protein. Re-expression of wild-type HMGN1, but not of the mutant HMGN1 protein that does not bind to chromatin, in Hmgn1-/- MEFs, decreased the levels of N-cadherin and restored the Hmgn1+/+ phenotype. These studies demonstrate a role for HMGN1 in the regulation of specific gene expression. We suggest that in MEFs, and during early mouse development, the interaction of HMGN1 with chromatin down-regulates the expression of N-cadherin.     

Aberrant expression of Arpin in human breast cancer and its clinical significance

Arpin (Arp2/3 complex inhibitor), a novel protein found in 2013, plays a pivotal role in cell motility and migration. However, the precise role of Arpin in cancer is unclear. This study investigated the expression of Arpin in breast cancer and evaluated its correlation with the characteristics of clinical pathology and prognosis of breast cancer patients. Immunohistochemistry (IHC) for Arpin protein was performed on formalin‐fixed, paraffin‐embedded 176 breast cancer tissues and 43 normal breast tissues while qRT‐PCR for Arpin mRNA with 104 paired tumour and paratumoural tissues from breast cancer patients respectively. The association of Arpin expression with clinical pathological features and survival was assessed in a retrospective cohort analysis of patients. The results showed that the expression of Arpin protein in cancer tissues was lower compared to that in normal breast and the expression of Arpin mRNA was also lower in cancer tissues than that in the matched paratumoural tissues. Among the 176 breast cancer patients, the lower expression of Arpin was significantly associated with advanced tumour, nodes and metastasis system stage, and the reduced Arpin expression was strongly associated with axillary lymph node metastasis using univariate and multivariate logistic regression analysis [odds ratio: 3.242; 95% confidence interval (CI): 1.526, 6.888; P < 0.05]. Furthermore, Arpin expression was an independent risk factor for recurrence‐free survival (HR: 0.373; 95% CI: 0.171, 0.813; P < 0.05). As Arpin expression was first examined in human breast cancer tissues with qRT‐PCR and IHC, our results suggest that Arpin downregulation may contribute to the initiation and development of breast cancer metastasis. Therefore, as a potential predictive marker, Arpin deserves future studies.     

Origin and functional significance of large-scale chromosomal imbalances in neuroblastoma

Neuroblastoma is characterized by numerous recurrent large-scale chromosomal imbalances and gene amplifications which are associated with poor clinical outcome. The most common include MYCN amplification, loss of 1p, 3p and 11q, and gain of 17q genomic regions. Two of these abnormalities, MYCN amplification and loss of 11q, define different genetic subtypes of the disease with vastly different global gene expression profiles. The progress towards the identification of the genes and genetic pathways that have been affected by these abnormalities is reviewed and high resolution mapping of the chromosomal breakpoint regions using oligonucleotide array CGH (oaCGH) is discussed. oaCGH analysis is proving useful for both defining minimal regions of overlap of imbalances, as well as providing information on the molecular mechanisms that generate the chromosomal imbalances. These high resolution analyses have also permitted the detection of micro-deletions in the tumors that further assist in identifying genes important for neuroblastoma pathogenesis.     

N-cadherin expression level as a critical indicator of invasion in non-epithelial tumors

Cancer cell dissemination away from the primary tumor and their ability to form metastases remain the major causes of death from cancer. Understanding the molecular mechanisms triggering this event could lead to the design of new cancer treatments. The establishment and the maintenance of tissue architecture depend on the coordination of cell behavior within this tissue. Cell-cell interactions must form adhesive structures between neighboring cells while remaining highly dynamic to allow and control tissue renewal or remodeling. Among intercellular junctions, cadherin-based adherens junctions mediate strong physical interactions and transmit information from the cell microenvironment to the cytoplasm. Disruption of these cell-cell contacts perturbs the polarity of epithelial tissues leading to their disorganization and ultimately to aggressive carcinomas. In non-epithelial tissues, the role of cadherins in the development of cancer is still debated. We recently found that downregulation of N-cadherin in malignant glioma—the most frequent primary brain tumor—results in cell polarization defects leading to abnormal motile behavior with increased cell speed and decreased persistence in directionality. Re-expression of N-cadherin in glioma cells restores cell polarity and limits glioma cell migration, providing a potential therapeutic tool for diffuse glioma.     

SRSF1和BIRC5在胃癌组织中的表达及临床意义

目的通过对丝氨酸/精氨酸富有剪接因子1(SRSF1)和凋亡抑制因子(BIRC5)在胃癌组织中表达的检测及两者之间相关性的研究,来探讨两者与胃癌的发生、发展之间的关系;为胃癌的转移及复发预警,以及预后评估提供新靶点。方法应用逆转录-聚合酶链式反应(RT-PCR)和蛋白质印迹(Western blotting)检测60例术中切除的胃癌肿组织以及对应的癌旁组织中SRSF1与BIRC5的表达水平,分析这两种蛋白的表达水平与临床病理学特征的关系。结果 (1)胃癌肿组织中SRSF1 mRNA和BIRC5mRNA表达情况:SRSF1阳性表达率(75.0%,45/60)高于癌旁组织中(8.3%,5/60);BIRC5阳性表达率(81.7%,49/60)高于癌旁组织中(11.7%,7/60)。胃癌肿组织中SRSF1mRNA与BIRC5mRNA的表达与患者的年龄、性别、肿瘤大小等因素无关,与胃癌肿组织的分化程度、淋巴结转移以及TNM分期有关;SRSF1和BIRC5 mRNA在胃癌肿组织中的阳性表达呈正相关(r=0.3496,P=0.0062)。(2)胃癌肿组织中SRSF1蛋白与BIRC5蛋白表达情况:胃癌肿组织中SRSF1蛋白表达量相较于其在癌旁组织中的表达量明显增多(t=44.87,P0.01),BIRC5蛋白表达量较癌旁组织同样异常增高(t=69.84,P0.01)。结论在胃癌肿组织中SRSF1和BIRC5表达均存在异常增高,与胃癌的发生发展存在正相关,这可能与SRSF1选择性剪接BIRC5片段,促进凋亡抑制基因BIRC5的高表达有关,具体机制还需进一步探讨。     

Prognostic and clinical significance of focal adhesion kinase expression in breast cancer: A systematic review and meta-analysis

BackgroundThe prognostic significance of focal adhesion kinase (FAK) in breast cancer remains controversial. Here, we conducted a meta-analysis to explore the prognostic value of FAK expression in breast cancer.Materials and methodsPossible prognostic significance of protein or mRNA expression of FAK in breast cancer was investigated with searches of electronic databases for relevant publications. Pooled hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs) were extracted from eligible studies.ResultsA total of eight eligible studies which included 2604 participants were analyzed in this meta-analysis. Increased expression of FAK protein was found to significantly correlate with shorter overall survival (OS) (HR = 1.43, 95% CI: 1.12–1.83; P = 0.004), and not with disease-free survival (HR = 1.31, 95% CI: 0.92–1.85; P = 0.14). Elevated FAK protein expression was also associated with negative estrogen receptor (ER) expression (OR, 1.34; 95% CI, 1.06–1.68; P = 0.01), negative progesterone receptor (PR) expression (OR, 1.54; 95% CI, 1.22–1.93; P < 0.001), positive human epidermal growth factor receptor 2 (HER2) expression (OR, 1.64; 95% CI, 1.28–2.09; P < 0.001), triple-negative breast cancer (TNBC) (OR, 1.57; 95% CI, 1.14–2.17; P = 0.006), high nuclear grade (OR, 1.70; 95% CI, 1.05–2.78; P = 0.03), high Ki-67 expression level (OR, 2.87; 95% CI, 1.94–4.24; P < 0.001), and positive p53 status (OR, 2.28; 95% CI, 1.58–3.29; P < 0.001).ConclusionOur meta-analysis identifies an association between increased FAK protein expression and worse OS among breast cancer patients. Moreover, enhanced FAK expression is associated with negative ER expression, negative PR expression, positive HER2 expression, TNBC, high nuclear grade, high Ki-67 expression level, and positive p53 status in breast carcinoma.