乳腺癌转移抑制因子BRMS1研究进展

癌转移是导致癌症患者死亡的主要原因, 因此, 研究癌转移的分子机制能为癌症的预后和治疗提供新的方法。癌转移抑制基因是一类只抑制癌细胞的转移而不影响肿瘤的发生与生长的基因。BRMS1是2000年在乳腺癌细胞中发现的癌转移抑制基因。它所编码的蛋白还可以抑制黑素瘤细胞和小鼠乳腺癌细胞的转移。BRMS1定位于核内, 与mSin3-HDAC复合体相互作用, 并且可以改变乳腺癌细胞的connexin表达特征, 从而恢复间隙连接介导的细胞间连接通讯。文章就BRMS1的研究进展做一综述, 对其相关的基因也给予简单的介绍, 并对它可能的作用机制进行了预测。     

Drug Allergy and the Risk of Lymph Node Metastasis in Rectal Cancer

Background

Previous epidemiologic studies have reported that a history of allergy is associated with reduced risk of colorectal cancer and other malignancies. However, no information is available for the association between allergy and the risk of lymph node metastasis. Our study was designed to determine this association in rectal cancer.

Methods

Patients who were treated at our hospital in the period from January 2003 to June 2011, and with a pathologically hospital discharge diagnosis of rectal adencarcinoma, were included. The clinical, laboratory, and pathologic parameters were analyzed. A multivariate logistic regression model was used to determine the association. Moreover, for type of allergic drug, sub-group analysis was performed.

Results

469 patients were included, including 231 with pathological lymph node metastasis (pLNM) (49.3%) and 238 without pLNM. Univariate analysis showed, compared with patients without pLNM, patients with pLNM had a younger age (60.6±12.8 yr vs. 63.6±12.2 yr, P = 0.012), a lower percentage of drug allergy (8.7% vs. 16.0%, P = 0.016), an increased CEA (median/interquartile-range 5.40/2.40–13.95 vs. 3.50/2.08–8.67, P = 0.009), and a lower serum sodium (141±3.1 mmol/L vs. 142±2.9 mmol/L, P = 0.028). Multivariate analysis showed that drug allergy was associated with a reduced risk of pLNM (OR = 0.553; 95% CI, 0.308–0.994; P = 0.048). In addition, our results showed that: (1) for tumor classification, patients with drug allergy had a higher percentage of group patients with pT1/pT2; and (2) for type of allergic drug, this inverse association was found for penicillins, not for other allergic drugs.

Conclusion

Drug allergy is associated with a reduced risk of pLNM in rectal cancer.     

直肠癌的淋巴结转移的危险因素

目的:本研究主要目的为确定直肠癌的淋巴结转移的危险因素。方法:通过对1250例于2004年-2008年行直肠癌根治性切除的患者进行单因素和多因素分析,以确定淋巴结转移相关的危险因素,同时对PT分期和肿瘤大小之间的关系进行了相关性分析。结果:直肠癌患者淋巴结转移发生率为41%。在单因素分析中,患者年龄(P=0.008)、肿瘤大小(P=0.003)、PT分期(P<0.0019)以及分化程度(P<0.001)和淋巴结转移相关。在多因素分析中,年龄(P=0.017,OR=0.988,95%可信区间:0.978-0.998)、PT分期(P<0.001,OR=1.952,95%可信区间:1.656-2.302)和分化程度(P<0.001,OR=3.697,95%可信区间:2.112-6.472)是淋巴结转移的独立因素。结论:在直肠癌相关分析中,肿瘤的大小和PT分期呈正相关。年龄、PT分期和肿瘤分化程度是淋巴结转移的独立因素。在直肠癌中,肿瘤的大小和PT分期呈正相关。     

An Orthotopic Murine Model of Human Prostate Cancer Metastasis

Our laboratory has developed a novel orthotopic implantation model of human prostate cancer (PCa). As PCa death is not due to the primary tumor, but rather the formation of distinct metastasis, the ability to effectively model this progression pre-clinically is of high value. In this model, cells are directly implanted into the ventral lobe of the prostate in Balb/c athymic mice, and allowed to progress for 4-6 weeks. At experiment termination, several distinct endpoints can be measured, such as size and molecular characterization of the primary tumor, the presence and quantification of circulating tumor cells in the blood and bone marrow, and formation of metastasis to the lung. In addition to a variety of endpoints, this model provides a picture of a cells ability to invade and escape the primary organ, enter and survive in the circulatory system, and implant and grow in a secondary site. This model has been used effectively to measure metastatic response to both changes in protein expression as well as to response to small molecule therapeutics, in a short turnaround time.     

Bmi1 Enhances Tumorigenicity and Cancer Stem Cell Function in Pancreatic Adenocarcinoma

Background

Bmi1 is an integral component of the Polycomb Repressive Complex 1 (PRC1) and is involved in the pathogenesis of multiple cancers. It also plays a key role in the functioning of endogenous stem cells and cancer stem cells. Previous work implicated a role for cancer stem cells in the pathogenesis of pancreatic cancer. We hypothesized that Bmi1 plays an integral role in enhancing pancreatic tumorigenicity and the function of cancer stem cells in pancreatic ductal adenocarcinoma.

Methods

We measured endogenous Bmi1 levels in primary human pancreatic ductal adenocarcinomas, pancreatic intraepithelial neoplasias (PanINs) and normal pancreas by immunohistochemistry and Western blotting. The function of Bmi1 in pancreatic cancer was assessed by alteration of Bmi1 expression in several cell model systems by measuring cell proliferation, cell apoptosis, in vitro invasion, chemotherapy resistance, and in vivo growth and metastasis in an orthotopic model of pancreatic cancer. We also assessed the cancer stem cell frequency, tumorsphere formation, and in vivo growth of human pancreatic cancer xenografts after Bmi1 silencing.

Results

Bmi1 was overexpressed in human PanINs, pancreatic cancers, and in several pancreatic cancer cell lines. Overexpression of Bmi1 in MiaPaCa2 cells resulted in increased proliferation, in vitro invasion, larger in vivo tumors, more metastases, and gemcitabine resistance while opposite results were seen when Bmi1 was silenced in Panc-1 cells. Bmi1 was overexpressed in the cancer stem cell compartment of primary human pancreatic cancer xenografts. Pancreatic tumorspheres also demonstrated high levels of Bmi1. Silencing of Bmi1 inhibited secondary and tertiary tumorsphere formation, decreased primary pancreatic xenograft growth, and lowered the proportion of cancer stem cells in the xenograft tissue.

Conclusions

Our results implicate Bmi1 in the invasiveness and growth of pancreatic cancer and demonstrate its key role in the regulation of pancreatic cancer stem cells.     

Dominant Expression of DCLK1 in Human Pancreatic Cancer Stem Cells Accelerates Tumor Invasion and Metastasis

Patients with pancreatic cancer typically develop tumor invasion and metastasis in the early stage. These malignant behaviors might be originated from cancer stem cells (CSCs), but the responsible target is less known about invisible CSCs especially for invasion and metastasis. We previously examined the proteasome activity of CSCs and constructed a real-time visualization system for human pancreatic CSCs. In the present study, we found that CSCs were highly metastatic and dominantly localized at the invading tumor margins in a liver metastasis model. Microarray and siRNA screening assays showed that doublecortin-like kinase 1 (DCLK1) was predominantly expressed with histone modification in pancreatic CSCs with invasive and metastatic potential. Overexpression of DCLK1 led to amoeboid morphology, which promotes the migration of pancreatic cancer cells. Knockdown of DCLK1 profoundly suppressed in vivo liver metastasis of pancreatic CSCs. Clinically, DCLK1 was overexpressed in the metastatic tumors in patients with pancreatic cancer. Our studies revealed that DCLK1 is essential for the invasive and metastatic properties of CSCs and may be a promising epigenetic and therapeutic target in human pancreatic cancer.     

STED Super-Resolution Microscopy of Clinical Paraffin-Embedded Human Rectal Cancer Tissue

Formalin fixed and paraffin-embedded human tissue resected during cancer surgery is indispensable for diagnostic and therapeutic purposes and represents a vast and largely unexploited resource for research. Optical microscopy of such specimen is curtailed by the diffraction-limited resolution of conventional optical microscopy. To overcome this limitation, we used STED super-resolution microscopy enabling optical resolution well below the diffraction barrier. We visualized nanoscale protein distributions in sections of well-annotated paraffin-embedded human rectal cancer tissue stored in a clinical repository. Using antisera against several mitochondrial proteins, STED microscopy revealed distinct sub-mitochondrial protein distributions, suggesting a high level of structural preservation. Analysis of human tissues stored for up to 17 years demonstrated that these samples were still amenable for super-resolution microscopy. STED microscopy of sections of HER2 positive rectal adenocarcinoma revealed details in the surface and intracellular HER2 distribution that were blurred in the corresponding conventional images, demonstrating the potential of super-resolution microscopy to explore the thus far largely untapped nanoscale regime in tissues stored in biorepositories.     

苜蓿素对人直肠癌SW1116细胞增殖和凋亡的作用及其机制

本文探讨苜蓿素对人直肠癌SW1116细胞增殖和凋亡的作用及其机制.采用MTr法检测苜蓿素对SW1116细胞生长的抑制作用;AO/EB染色后观察凋亡细胞形态;流式细胞术检测对细胞周期的影响;DNA片段化分析对细胞凋亡的作用;Westem blot检测对Bcl-2和Bax蛋白表达的影响.结果显示,苜蓿素可明显抑制SW1116细胞的增殖,呈剂量依赖性;AO/EB染色观察到给药组出现细胞凋亡特征;苜蓿素可阻滞细胞于G1/G1期和增加SW1116细胞凋亡率;凝胶成像分析仪检测到典型的DNA阶梯状条带;苜蓿素可呈剂量依赖地减弱Bcl-2和增强Bax蛋白表达.上述结果表明,苜蓿素可显著抑制人直肠癌SW1116细胞的增殖,使细胞阻滞于G1/G1期,并可诱导细胞凋亡,其机制可能与下调Bcl-2和上调Bax蛋白有关.     

Human Papillomavirus and Cystic Node Metastasis in Oropharyngeal Cancer and Cancer of Unknown Primary Origin

The clinical significance of human papillomavirus (HPV) in neck node metastasis from cancer of unknown primary (CUP) is not well established. We aimed to address the relationship of HPV status between node metastasis and the primary tumor, and also the relevance of HPV status regarding radiographically detected cystic node metastasis in head and neck squamous cell carcinoma (HNSCC) and CUP. HPV DNA was examined in 68 matched pairs of node metastasis and primary tumor, and in node metastasis from 27 CUPs. In surgically treated CUPs, p16 was examined immunohistochemically. When tonsillectomy proved occult tonsillar cancer in CUP, HPV DNA and p16 were also examined in the occult primary. Cystic node metastasis on contrast-enhanced computed tomography scans was correlated with the primary site and HPV status in another series of 255 HNSCCs and CUPs with known HPV status. Node metastasis was HPV-positive in 19/37 (51%) oropharyngeal SCCs (OPSCCs) and 10/27 (37%) CUPs, but not in non-OPSCCs. Fluid was collected from cystic node metastasis using fine needle aspiration in two OPSCCs and one CUP, and all fluid collections were HPV-positive. HPV status, including the presence of HPV DNA, genotype, and physical status, as well as the expression pattern of p16 were consistent between node metastasis and primary or occult primary tumor. Occult tonsillar cancer was found more frequently in p16-positive CUP than in p16-negative CUP (odds ratio (OR), 39.0; 95% confidence interval (CI), 1.4–377.8; P = 0.02). Radiographically, cystic node metastasis was specific to OPSCC and CUP, and was associated with HPV positivity relative to necrotic or solid node metastasis (OR, 6.2; 95% CI, 1.2–45.7; P = 0.03). In conclusion, HPV status remains unchanged after metastasis. The occult primary of HPV-positive CUP is most probably localized in the oropharynx. HPV status determined from fine needle aspirates facilitates the diagnosis of cystic node metastasis.     

Post-Operative Plasma Osteopontin Predicts Distant Metastasis in Human Colorectal Cancer

BackgroundThe overall prognosis of colorectal cancer (CRC) patients is unsatisfactory due to cancer metastasis after operation. This study aims to investigate the clinical significance of plasma osteopontin (OPN) levels as minimally invasive, predictive, and surrogate biomarkers for prognosis of CRC patients.MethodsThis randomized study design consists of pre-operative and post-operative plasma samples from a total of 79 patients. We determined plasma levels of OPN by ELISA and examined their correlation with the clinicopathological parameters of CRC patients. The effects of endogenous and exogenous OPN on CRC metastasis were investigated by examination of the effect on regulators of epithelial to messenchymal transition and migration assay.ResultsOur findings demonstrated for the first time the clinical correlation of plasma OPN with metastasis of CRC patients. High post-operative plasma OPN level (>153.02 ng/ml) associated with development of metastasis after curative resection (p<0.001). Moreover, post-operative plasma OPN level correlated with disease-free survival of CRC patients (p=0.009) and was an independent factor for predicting development of metastasis in CRC patients after curative resection (p=0.036). Our in vitro model showed that OPN ectopic expression induced DLD1 cell migration through Snail and Twist1 overexpression and E-cadherin repression, and secretory OPN level enhanced cell migration.ConclusionsThe results of the current study suggest that post-operative plasma OPN correlated with post-operative metastasis, suggesting that it is a potential non-invasive biomarker for the development of future metastasis in CRC patients. In addition, OPN was shown to be involved in the metastatic process and thus inhibition of OPN is a potential therapeutic approach to treat CRC patients.     

BRMS1与乳腺癌腋窝淋巴结微转移的临床研究

目的:探讨BRMS1的表达与乳腺癌腋窝淋巴结微转移的关系.方法:采用连续切片和CK-19联合检测86例腋窝淋巴结转移阴性的所有淋巴结微转移灶的情况,术后随访其复发情况,免疫组化检测乳腺癌组织中BRMS1的表达并分析其与淋巴结微转移及术后复发率的关系.结果:86例乳腺癌腋窝淋巴结转移阴性的689淋巴结中有48粒(6.97％)检测到微转移,其中阳性病例22例(25.58％),BRMS1的表达阴性的乳腺癌患者腋窝淋巴结微转移病例率(43.24％)和术后复发率(54.05％)远高于BRMS1表达阳性的乳腺癌患者(12.24％,8.16％),差异具有显著性,且呈明显的负相关.结论:BRMS1与腋窝淋巴结微转移密切相关,可以成为乳腺癌腋窝淋巴结微转移分子指标,并对乳腺癌的分期、预后、治疗具有重要的指导意义.     

芦荟大黄素对人甲状腺癌细胞K1的促凋亡作用

目的:研究芦荟大黄素促进人甲状腺癌细胞系K1凋亡的作用.方法:人甲状腺癌细胞系K1与不同浓度的芦荟大黄素共孵育48h,MTT法检测细胞存活率,并用相差显微镜观察细胞形态学改变.用流式细胞术(检测细胞凋亡相关指标Annexin V/PI)和Hoeehst33258染色检测细胞凋亡,结果:芦荟大黄素能够不同程度地抑制人甲状腺癌细胞系K1的生长.芦荟大黄素对K1细胞的IC50(半教抑制浓度)分别为65 mg/ml.Hoechst33258荧光染色和流武细胞术分析K1细胞的结果一致.结论:芦荟大黄素可促进K1细胞凋亡,为芦荟大黄素治疗甲状腺癌提供了依据.     

NDRG1对人肠癌细胞失巢凋亡的影响

目的:探讨NDRG1对体外培养的人肠癌细胞系失巣凋亡的影响。方法:采用慢病毒系统将NDRG1表达单元转入人肠癌细胞系SW620、HCT8中,建立相应的过表达稳定细胞系;通过siRNA的方法干扰HCT116和LOVO细胞系中NDRG1的表达,分别在非贴壁培养的情况下培养48小时,采用流式细胞术和TUNEL染色检测细胞的凋亡情况。结果:在贴壁培养条件下,NDRG1过表达并没有显著影响肠癌细胞的生长及增殖,而NDRG1特异性siRNA干扰HCT116细胞中NDRG1的表达后,其凋亡率无明显变化(P0.05)。在悬浮培养条件下,NDRG1过表达的肠癌细胞的失巢凋亡率显著低于正常对照组(P0.05),而用三种不同的siRNA干扰HCT116及LOVO细胞中NDRG1的表达后,其失巢凋亡率均显著高于正常对照组(P0.05)。结论:NDRG1在体外可抑制人肠癌细胞的失巢凋亡。     

人卵巢癌A2780 细胞侵袭转移与HES1 相关性

目的:探讨人卵巢癌细胞A2780中的HES1表达与人卵巢癌侵袭及转移的关系。方法:分别运用实时RT-PCR、WesternBlotting及细胞免疫荧光法检测γ分泌酶抑制剂作用前后A2780细胞中HES1的表达水平,Transwell小室试验及MTT法分别用于检测细胞的侵袭、迁移及黏附能力。结果:下调A2780细胞中HES1的表达水平后,A2780细胞的黏附、侵袭及转移能力下降,差异有统计学意义(P<0.01)。结论:HES1的表达与人卵巢癌细胞的侵袭及转移密切相关,下调其表达可抑制卵巢癌细胞的黏附、侵袭及转移能力。