胃腺癌组织中GDF-15和p53表达特征及其临床意义

目的探讨胃腺癌及癌旁正常组织中生长分化因子15(growth differentiation factor-15,GDF-15)和p53表达的特征及临床意义。方法采用免疫组织化学Polink-1两步法检测91例胃癌手术标本,相应91例癌旁正常组织、64例肠化腺体及36例淋巴结转移癌组织中GDF-15和p53的表达特征,并结合临床资料分析其表达与临床病理参数的关系。结果 GDF-15在肠上皮化生腺体、胃腺癌和淋巴结转移癌组织中的阳性表达率均显著低于癌旁组织。GDF-15的阳性表达率与患者年龄、浸润深度、淋巴结转移及p TNM分期呈正相关,而与其它临床病理参数无关。p53在癌旁正常胃粘膜腺体和肠上皮化生腺体中均不表达,在胃腺癌和淋巴结转移癌组织中的过表达阳性率均高于癌旁组织和肠上皮化生腺体。p53过表达的阳性率与患者年龄、Lauren分型(肠型与弥漫型)和分化程度呈正相关,而与其它临床病理参数无关。GDF-15与p53免疫反应性在胃癌组织中呈正相关。结论 GDF-15可作为胃腺癌的胃壁浸润能力、淋巴结转移能力及临床病理分期的重要评价指标,而p53过表达可能与Lauren分型的肠型胃癌有关。尤其在老年患者中,GDF-15和p53过表达在胃腺癌的发生、进展中扮演重要角色,并起协同作用。     

胃癌螺旋CT表现与Cath-D蛋白和MMP-9 表达的关系分析

目的:观察分析胃癌螺旋CT表现与组织蛋白酶D(Cath-D)蛋白和基质金属蛋白酶-9(MMP-9)表达的关系。方法:采集自2014年9月至2015年9月在医院经过胃癌手术治疗的54例患者自身胃癌组织标本进行本次研究。再选同期在医院就诊并经过手术治疗的54例胃溃疡患者自身胃黏膜组织进行对照。分别检测MMP-9以及Cath-D蛋白的表达,对所有胃癌患者给予螺旋CT诊断。结果:MMP-9及Cath-D蛋白在胃癌组织内的阳性表达率为74.07%及77.79%,显著高于在正常胃黏膜内的5.56%及9.26%,差异均有统计学意义(P0.05)。MMP-9及Cath-D表达存在明显正相关(r=0.693,P0.05)。胃癌组织内有淋巴结转移及Lauren分型为弥漫型的MMP-9及Cath-D阳性表达率均显著高于无淋巴结转移及Lauren分型为肠型者,差异有统计学意义(P0.05)。根据Logistic回归分析可知,有淋巴结转移以及Lauren分型为弥漫型是胃癌组织内MMP-9及Cath-D表达的螺旋CT表现相关因素。结论:胃癌患者组织内的MMP-9及Cath-D表达比正常胃黏膜组织更高,MMP-9及Cath-D二者的表达呈现正相关,且有淋巴结转移以及Lauren分型为弥漫型是胃癌组织内MMP-9及Cath-D表达的螺旋CT表现相关因素。     

幽门螺杆菌感染性胃癌组织中cyclinD1、MMP-9的表达及其临床意义

目的:探讨幽门螺杆菌(HP)感染性胃癌组织中细胞周期蛋白D1(cyclinD1)、基质金属蛋白酶-9(MMP-9)的表达及其临床意义。方法:选取2016年12月到2018年6月期间在兰州大学第一医院接受治疗的胃癌患者80例,收集其手术切除的病理组织。采用C-14呼气试验和改良Giemsa染色检测患者HP感染的情况,采用免疫组化法检测胃癌组织中cyclinD1、MMP-9表达情况。分析HP感染、cyclinD1、MMP-9表达与胃癌患者临床病理特征的关系,并分析胃癌患者HP感染与cyclinD1、MMP-9表达的相关性。结果:80例胃癌患者HP感染阳性56例(70.00%),阴性24例(30.00%)。有淋巴结转移、浸润深度为T3+T4的胃癌患者的HP感染阳性率高于无淋巴结转移、浸润深度为T1+T2的胃癌患者(P0.05)。80例胃癌患者cyclinD1阳性表达45例(56.25%),阴性表达35例(43.75%),MMP-9阳性表达65例(81.25%),阴性表达15例(18.75%),TNM临床分期为III+IV期、分化程度为低分化、有淋巴结转移、浸润深度为T3+T4的胃癌患者的cyclinD1、MMP-9阳性表达率明显高于TNM临床分期为I+II期、分化程度为中高分化、无淋巴结转移、浸润深度为T1+T2的胃癌患者(P0.05)。HP感染阳性患者的cyclinD1阳性表达率和MMP-9阳性表达率均明显高于HP感染阴性患者(P0.05)。Pearson相关分析显示,胃癌患者HP感染与cyclinD1、MMP-9表达均呈正相关(P0.05)。结论:胃癌患者的HP感染情况与淋巴结转移、浸润深度有关,cyclinD1和MMP-9的表达与TNM临床分期、分化程度、淋巴结转移、浸润深度有关,且胃癌患者HP感染与cyclinD1、MMP-9表达均呈正相关。     

PKCβ Ⅱ和EGFR在胃癌中的表达及意义

目的：检测蛋白激酶CβⅡ亚型（PKCβⅡ）、表皮生长因子受体（EGFR）在胃癌组织中的表达,探讨其与胃癌临床病理特征的关系。方法：应用免疫组化（S-P法）检测105例癌旁正常胃组织和手术切除胃癌标本中PKCβⅡ、EGFR的表达状况,并将检测结果与临床病理特征进行综合分析。结果：癌组织和癌旁正常胃组织PKCβⅡ阳性表达率分别为62.86%和44.76%,二者之间有显著性差异（P〈0.05）;EGFR阳性表达率分别为46.67%和7.62%二者之间亦具有显著性差异（P〈0.05）。PKCβⅡ和EGFR的表达呈正相关（P〈0.05）,它们的表达与胃癌组织学类型、浸润深度、淋巴结转移、组织学分级、临床TNM分期相关（P〈0.05）,与患者的性别,年龄无关（P〉0.05）。结论：PKCβⅡ和EGFR在胃癌组织中均存在高表达,与胃癌组织类型、分化程度、浸润深度、淋巴结转移以及临床TNM分期有一定关系。联合检测两种指标有望对胃癌发生发展的研究、判断预后及靶向治疗提供依据。     

PKCβⅡ和EGFR在胃癌中的表达及意义

目的:检测蛋白激酶CβⅡ亚型(PKCβⅡ)、表皮生长因子受体(EGFR)在胃癌组织中的表达,探讨其与胃癌临床病理特征的关系.方法:应用免疫组化(S-P法)检测105例癌旁正常胃组织和手术切除胃癌标本中PKCβⅡ、EGFR的表达状况,并将检测结果与临床病理特征进行综合分析.结果:癌组织和癌旁正常胃组织PKCβⅡ阳性表达率分别为62.86%和44.76%,二者之间有显著性差异(P<0.05);EGFR阳性表达率分别为46.67%和7.62%二者之间亦具有显著性差异(P<0.05).PKCβⅡ和EGFR的表达呈正相关(P<0.05),它们的表达与胃癌组织学类型、浸润深度、淋巴结转移、组织学分级、临床TNM分期相关(P<0.05),与患者的性别,年龄无关(P0.05).结论:PKCβⅡ和EGFR在胃癌组织中均存在高表达,与胃癌组织类型、分化程度、浸润深度、淋巴结转移以及临床TNM分期有一定关系.联合检测两种指标有望对胃癌发生发展的研究、判断预后及靶向治疗提供依据.     

食管鳞癌VEGF-C mRNA和CD31表达及其意义

研究食管鳞癌血管内皮生长因子C(VEGF-C)mRNA和CD 31的表达,探讨VEGF-C促食管鳞癌淋巴转移的作用。应用原位杂交法检测43例食管鳞癌组织VEGF-C mRNA表达,CD 31免疫组织化学染色标记血管、淋巴管内皮细胞,并计数肿瘤组织的微血管密度(MVD)。结果显示,食管鳞癌组织VEGF-C mRNA阳性19例(41.86%),MVD平均为76.36±20.30/mm~2。VEGF-C mRNA表达与食管鳞癌淋巴结转移、TNM分期和肿瘤浸润深度相关(p<0.05或p<0.01);而与肿瘤组织学分级无关(p>0.05)。MVD与食管鳞癌淋巴结转移、TNM分期的相关性有统计学意义(p<0.05);而与肿瘤浸润深度和组织学分级的相关性则无统计学意义(p>0.05)。VEGF-C mRNA表达阳性者MVD高于表达阴性者,两者比较具有显著性差异(p<0.05)。研究提示VEGF-C促进了肿瘤诱导的淋巴管新生和血管新生,在食管鳞癌的淋巴转移中起重要作用。     

VEGF、CD34、VEGF—C和VEGFR-3在胃癌中的表达及临床意义

目的：探讨胃癌组织中VEGF、CD34、VEGF-C和VEGFR-3的表达情况及临床意义。方法：采用免疫组化方法测定81例胃癌组织VEGF、CD34、VEGF—C和VEGFR-3表达情况,并结合患者的临床病理资料进行分析。结果：81例胃癌组织中MVD平均值为（42.95±14．79）个／视野,范围为13．00-68．33个／视野,VEGF、VEGF—C、VEGFR-3阳性表达率分别为74．1％、64．2％、67．9％。VEGF的表达与肿瘤的TNM分期、浸润深度、淋巴结转移有关,CD34的表达与肿瘤的分化程度、TNM分期、浸润深度、淋巴结转移有关,VEGF—C的表达与肿瘤的分化程度、浸润深度、淋巴结转移有关,VEGFR-3的表达与肿瘤的浸润深度、淋巴结转移有关。结论：VEGF、CD34、VEGF—C和VEGFR-3的表达与胃癌的浸润转移密切相关。     

VEGF、CD34、VEGF-C和VEGFR-3在胃癌中的表达及临床意义

目的：探讨胃癌组织中VEGF、CD34、VEGF-C和VEGFR-3的表达情况及临床意义。方法：采用免疫组化方法测定81例胃癌组织VEGF、CD34、VEGF—C和VEGFR-3表达情况,并结合患者的临床病理资料进行分析。结果：81例胃癌组织中MVD平均值为（42.95&#177;14．79）个／视野,范围为13．00-68．33个／视野,VEGF、VEGF—C、VEGFR-3阳性表达率分别为74．1％、64．2％、67．9％。VEGF的表达与肿瘤的TNM分期、浸润深度、淋巴结转移有关,CD34的表达与肿瘤的分化程度、TNM分期、浸润深度、淋巴结转移有关,VEGF—C的表达与肿瘤的分化程度、浸润深度、淋巴结转移有关,VEGFR-3的表达与肿瘤的浸润深度、淋巴结转移有关。结论：VEGF、CD34、VEGF—C和VEGFR-3的表达与胃癌的浸润转移密切相关。     

胃癌组织中COX-2和nm23的表达及意义

目的:探讨环氧合酶-2(COX-2)和nm23蛋白在胃癌组织中的表达及意义.方法:应用免疫组化方法检测了52胃癌组织及20正常胃黏膜中COX-2和nm23的表达,并在显微镜下计数阳性细胞数,统计比较胃癌组织和正常组织中COX-2和nm23的阳性表达率.结果:COX-2蛋白在胃癌组织和正常胃黏膜组织中阳性表达率分别为67.3%和5.0%,胃癌组织中COX-2蛋白阳性率显著高于正常胃黏膜(P＜0.01).nm23蛋白在胃癌组织和正常胃黏膜组织中阳性表达率分别为30.7%和75.0%,胃癌组织中nm23蛋白阳性率显著低于正常胃黏膜(P＜0.01).COX-2的异常表达与肿瘤细胞分化程度、肿瘤浸润深度、淋巴结转移、TNM分期显著相关(P＜0.05).nm23阳性表达率与肿瘤浸润深度、淋巴结转移、TNM分期显著相关(P＜0.05),而与肿瘤细胞分化程度无显著性相关(P＞0.05).结论:COX-2与nm23表达与胃癌的临床病理特征密切相关.COX-2与nm23可作为反映胃癌侵袭转移、判断预后的生物学指标.     

RhoGDI2和CIAPIN1在肝癌组织中的表达及其临床病理意义

目的:探讨RhoGDI2和CIAPIN1在肝癌组织中的表达情况及临床病理意义。方法:选取2013年5月~2015年9月在我院接受治疗的肝癌患者112例,应用免疫组化法检测112例肝癌组织标本、癌旁正常肝组织标本中RhoGDI2和CIAPIN1两种蛋白的表达情况,并分析两种蛋白的表达与肝癌增殖侵袭的相关性。从GEO datasets数据库中搜索出与肝癌增殖侵袭相关的基因数据,使用GEO2R分析肝癌组织中与RhoGDI2或CIAPIN1表达一致或相反的基因数据,最后应用DAVID对这些基因进行基因信号通路富集,找到RhoGDI2和CIAPIN1调控肝癌增殖侵袭的可能作用机制。结果:肝癌组织中,RhoGDI2和CIAPIN1表达阳性率分别为66.96%、27.68%,RhoGDI2的表达与淋巴结转移和远处转移密切相关,与患者的年龄、性别、原发灶分期、原发灶直径、组织学分级及TNM分期等均无相关性,而CIAPIN1在肝癌中的表达与患者年龄、性别、原发灶分期、原发灶直径、淋巴结转移及远处转移并无密切相关性,仅与组织学分级、TNM分期密切相关,其中RhoGDI2的表达与癌细胞转移呈正相关,而CIAPIN1的表达与肝癌组织学分级呈负相关,与TNM分级呈正相关。通过基因信号通路富集分析显示肝癌组织中RhoGDI2可能是通过PI3K-Akt-mTOR和Rho-ROCK信号通路介导肝癌细胞的增殖侵袭,而CIAPIN1可能是通过调控ERK1/2-MAPK通路影响肝癌增殖侵袭。结论:RhoGDI2和CIAPIN1在肝癌组织中均呈高表达,RhoGDI2的高表达可能会促进肝癌细胞的淋巴及远处转移,而CIAPIN1与肝癌细胞转移无关,与肝癌发生的严重状况密切相关。二者可能是通过不同的信号通路共同介导肝癌细胞的分化、转移等。     

P-gp、MMP-2、C-erbB-2在乳腺癌原发灶和转移淋巴结中的表达对比研究

目的：探讨乳腺癌侵袭转移和多药耐药之间的关系,为治疗方案的个体化提供依据。方法：采用免疫组化方法检测46例乳腺浸润性导管癌患者乳腺原发灶及相应腋淋巴结转移灶中P-gp、MMP-2、c-erbB-2的表达,结合临床表现、病理学指标,分析其相关性。结果：46例原发灶P-gp阳性表达35例（76.1%）,MMP-2阳性表达25例（54.3%）,c-erbB-2高表达18例（39.1%）;相应腋淋巴结转移灶P-gp阳性表达28例（60.9%）,MMP-2阳性表达16例（34.8%）,c-erbB-2高表达16例（34.8%）;P-gp、MMP-2蛋白表达水平与肿块大小、淋巴结转移数目均呈正相关（P〈0.05）,c-erbB-2蛋白表达水平与腋窝淋巴结转移数量呈正相关,与ER、PR表达呈负相关,P-gp阳性表达与MMP-2和c-erbB-2的表达呈正相关（P〈0.05）。结论：肿瘤原发灶与转移灶存在异质性,P-gp、MMP-2、c-erbB-2的表达与乳腺癌的多药耐药和侵袭转移有关,检测上述基因在原发灶与转移灶的表达,为乳腺癌选择个体化的化疗、内分泌治疗及分子靶向治疗提供了分子生物学依据。     

Immunohistochemical consistency between primary tumors and lymph node metastases of gastric neuroendocrine carcinoma

ABSTRACT: BACKGROUND: Gastric neuroendocrine carcinoma (G-NEC) is a rare, highly malignant tumor that exhibits aggressive growth leading to vascular invasion, distant metastasis and extremely poor prognosis. We studied the clinicopathological findings of seven patients at our institute to better under this disease. METHODS: Seven cases of G-NEC were identified among 1,027 cases of gastric carcinoma that underwent gastrectomy at Kansai Rousai Hospital between 2002 and 2010. We studied the pathological and immunohistochemical features of gastric neuroendocrine carcinomas at both the primary site and metastatic lymph nodes. RESULTS: The mean patient age was 73 years (range 63 to 86 years). There were no females in this series. The final staging was Stage I in one case, Stage II in two, Stage III in two and Stage IV in two. A total of 31 metastatic lymph nodes were found in these patients. This study revealed that the ratio of neuroendocrine cells was similar between the primary and metastatic sites, which tended to show the same expression patterns of neuroendocrine markers. CONCLUSIONS: Metastatic lymph nodes showed heterogeneous immunohistochemical expression patterns similar to the primary sites. G-NEC is far advanced at diagnosis and rapidly reaches the lymph nodes retaining its heterogeneity, carrying a worse prognosis than common gastric cancer.     

胃癌组织中PTEN、VEGF表达与肿瘤新生血管形成

目的探讨胃癌组织中PTEN、vascular endothelial growthfactor（VEGF）基因表达及其与肿瘤侵袭转移的关系。方法用RT-PCR和免疫组化方法检测胃癌、淋巴结转移组织中PTEN、VEGF mRNA和蛋白表达;用CD34检测肿瘤细胞微血管数。结果PTEN和VEGF mRNA表达阳性率在正常胃黏膜为76.5%与0.0%、胃癌组织为30.9%与69.1%、淋巴结转移组织23.6%与74.5%;PTEN和VEGF蛋白阳性率在正常胃黏膜为76.5%与0.0%、胃癌组织27.9%与82.4%、淋巴结转移组织16.3%与91.0%;胃癌组织中新生血管呈浸润生长,以淋巴结转移组织中明显。胃癌组织PTEN mRNA和蛋白低于正常胃黏膜（P〈0.01）,VEGF高于正常胃黏膜（P〈0.01）,PTEN与VEGF表达负相关（P〈0.05）,VEGF表达与新生血管形成正相关（P〈0.05）。结论PTEN基因失活和VEGF的过表达与新生血管形成相关,可能是通过调节包括VEGF在内的血管生成因子而在血管形成中起作用。     

HER-2/neu gene in primary and local metastatic axillary lymph nodes in human breast tumors.

In order to verify whether the HER-2/neu gene is involved in the initial phases of neoplastic disease or in its progression, we evaluated the amplification and overexpression of this gene in the primary tumor and in synchronous metastatic axillary lymph nodes of 26 women with operable breast cancer. HER-2/neu was amplified in 35% and overexpressed in 33% of the primary sites; similar percentages were found in lymph nodes. The clear correlation between the two disease sites regarding gene, mRNA and protein levels, supports the hypothesis that this gene is involved in the initial and invasive phases of neoplasia. Its actual role with respect to other biological tumor characteristics during the metastatic process should be investigated further.     

Epigenetic silencing of olfactomedin-4 enhances gastric cancer cell invasion via activation of focal adhesion kinase signaling

Downregulation of olfactomedin-4 (OLFM4) is associated with tumor progression, lymph node invasion and metastases. However, whether or not downregulation of OLFM4 is associated with epigenetic silencing remains unknown. In this study, we investigate the role of OLFM4 in gastric cancer cell invasion. We confirm the previous result that OLFM4 expression is increased in gastric cancer tissues and decreases with an increasing number of metastatic lymph nodes, which are associated with OLFM4 promoter hypermethylation. Overexpression of OLFM4 in gastric cancer cells had an inhibitory effect on cell invasion. Furthermore, we found that focal adhesion kinase (FAK) was negatively correlated with OLFM4 in regards to lymph node metastasis in gastric cancer tissues. Also, inhibition of FAK induced by OLFM4 knockdown resulted in a decrease in cell invasion. Thus, our study demonstrates that epigenetic silencing of OLFM4 enhances gastric cancer cell invasion via activation of FAK signaling. [BMB Reports 2015; 48(11): 630-635]     

Upregulation of the GRIM-19 gene suppresses invasion and metastasis of human gastric cancer SGC-7901 cell line

Gene associated with retinoid-IFN-induced mortality 19 (GRIM-19), as a novel IFN-β/RA-inducible gene product, was identified as a potential tumor suppressor associated with growth inhibition and cell apoptosis. Recently, it has been reported that the apoptotic effects and apoptosis-related gene induction of GRIM-19 can be attenuated by GW112, indicating that GRIM-19 and GW112 are involved in a common signal transduction pathway. To investigate the signaling mechanisms that link GRIM-19 to GW112 and their functional role in tumor cell invasion and metastasis, we utilized adenovirus-mediated overexpression of GRIM-19 in the gastric cancer SGC-7901 cell line. We observed that enhanced expression of GRIM-19 not only downregulated GW112 but also decreased NF-кB binding activity. As a result, we found that tumor cell adhesion, migration, invasion and liver metastasis were inhibited. Additionally, upregulation of GRIM-19 also suppressed secretion of urokinase-type plasminogen activator (u-PA), matrix metalloproteinase (MMP)-2, 9 and vascular endothelial growth factor (VEGF). These results indicate that GRIM-19 acts as an upstream regulator of GW112 to block NF-кB binding activity, thereby inhibiting gastric cancer cell migration, invasion and metastasis. We conclude that adenoviral transfer of the GRIM-19 gene may be an efficacious approach to controlling the invasion and metastasis of human gastric cancer.     

Ratio between Negative and Positive Lymph Nodes Is Suitable for Evaluation the Prognosis of Gastric Cancer Patients with Positive Node Metastasis

Objective

To date, there is no consensus to evaluate the most appropriate category of the nodal metastasis for precise predication the prognosis of gastric cancer patients with positive node metastasis after curative surgery.

Methods

We retrospectively analyzed the clinicopathologic characteristics and overall survival (OS) of 299 gastric cancer patients with positive node metastasis after curative surgery for evaluation the optimal category of the nodal metastasis.

Results

With the univariate and multivariate survival analyses, the depth of primary tumor invasion was identified as the independent predicators with the OS of 299 gastric cancer patients with nodal metastasis postoperatively, as were the number of positive lymph nodes (PLNs), the number of negative lymph nodes (NLNs), and the ratio between negative and positive lymph nodes (RNPL). The RNPL was identified to be more suitable for predication the OS of gastric cancer patients with positive node metastasis than the ratio between positive and dissected lymph nodes (RPDL) by using the stratum procedure of survival analysis. Besides, we found both PLNs and NLNs were independently correlated with OS of gastric cancer patients with nodal metastasis when RNPL, instead of RPDL, was controlled in the partial correlation model.

Conclusions

RNPL, a new category of the nodal metastasis, was suitable for predication the OS of gastric cancer patients with nodal metastasis after curative resection, as were the PLNs, and NLNs.     

Expression of nm23-H1 gene product in thyroid,ovary, and breast cancers

The nm23 gene product is one of several possible mediators of cancer invasion and metastasis. As the amounts of nm23-H1 mRNA and gene product are reduced in metastatic lymph nodes from patients with papillary carcinoma of the thyroid, we examined the expression of nm23 gene product in 115 thyroid cancers, 78 ovarian cancers, 63 breast cancers, and metastatic lymph node tissues by immunohistochemistry. It was found that nm23-H1, but not nm23-H2 gene product, was expressed in primary sites of thyroid, ovarian, and breast cancers, except for medullary and anaplastic carcinomas of the thyroid, but expressed only weakly or poorly in metastatic lymph nodes. Although nm23-H1 gene product expression was lower in anaplastic and medullary carcinomas of the thyroid, there was no significant difference in nm23-H1 gene product expression among histological types of ovarian and breast cancers. Our data indicate that the nm23-H1 gene product may play a role in metastasis in these hormone-producing organs and that other factors may be involved in metastasis of anaplastic and medullary carcinomas of the thyroid.     

Metastatic tumor evolution and organoid modeling implicate TGFBR2 as a cancer driver in diffuse gastric cancer

Background

Gastric cancer is the second-leading cause of global cancer deaths, with metastatic disease representing the primary cause of mortality. To identify candidate drivers involved in oncogenesis and tumor evolution, we conduct an extensive genome sequencing analysis of metastatic progression in a diffuse gastric cancer. This involves a comparison between a primary tumor from a hereditary diffuse gastric cancer syndrome proband and its recurrence as an ovarian metastasis.

Results

Both the primary tumor and ovarian metastasis have common biallelic loss-of-function of both the CDH1 and TP53 tumor suppressors, indicating a common genetic origin. While the primary tumor exhibits amplification of the Fibroblast growth factor receptor 2 (FGFR2) gene, the metastasis notably lacks FGFR2 amplification but rather possesses unique biallelic alterations of Transforming growth factor-beta receptor 2 (TGFBR2), indicating the divergent in vivo evolution of a TGFBR2-mutant metastatic clonal population in this patient. As TGFBR2 mutations have not previously been functionally validated in gastric cancer, we modeled the metastatic potential of TGFBR2 loss in a murine three-dimensional primary gastric organoid culture. The Tgfbr2 shRNA knockdown within Cdh1^-/-; Tp53^-/- organoids generates invasion in vitro and robust metastatic tumorigenicity in vivo, confirming Tgfbr2 metastasis suppressor activity.

Conclusions

We document the metastatic differentiation and genetic heterogeneity of diffuse gastric cancer and reveal the potential metastatic role of TGFBR2 loss-of-function. In support of this study, we apply a murine primary organoid culture method capable of recapitulating in vivo metastatic gastric cancer. Overall, we describe an integrated approach to identify and functionally validate putative cancer drivers involved in metastasis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13059-014-0428-9) contains supplementary material, which is available to authorized users.     

Upregulation of the Non-Coding RNA OTUB1-isoform 2 Contributes to Gastric Cancer Cell Proliferation and Invasion and Predicts Poor Gastric Cancer Prognosis

Background: The deubiquitinase OTUB1 plays critical oncogenic roles and facilitates tumor progression in cancer. However, less is known regarding the aberrant expression, clinical significance and biological functions of the non-coding RNA OTUB1-isoform 2. We aimed to evaluate the OTUB1-isoform 2 levels in gastric cancer and their possible correlation with clinicopathologic features and patient survival to reveal its biological effects in gastric cancer progression.Methods: Total RNA extraction was performed on 156 gastric cancer case samples, and RT-qPCR was conducted. Chi-square test analysis was used to calculate the correlation between pathological parameters and the OTUB1-isoform 2 mRNA levels. Kaplan-Meier and Cox proportional hazards analyses were used to analyze the overall survival (OS) and disease-free survival (DFS) rates. Nuclear and cytoplasmic RNAs were isolated to detect the subcellular localization of OTUB1-isoform 2. We also assessed whether overexpression of OTUB1-isoform 2 influenced in vitro cell proliferation, cell cycle progression, tumor cell invasion and migration, as well as in vivo nude mouse xenograft and metastasis models.Results: The OTUB1-isoform 2 expression levels were higher in the gastric cancer samples than in the paratumorous gland samples. OTUB1-isoform 2 expression levels tightly correlated with tumor size, lymph node metastasis and TNM staging. Higher OTUB1-isoform 2 expression levels led to significantly poorer OS and DFS rates, and a multivariate analysis revealed that OTUB1-isoform 2 was an independent risk factor for DFS. OTUB1-isoform 2 was predominantly localized in the cell nucleus. Ectopic overexpression of OTUB1-isoform 2 in gastric cancer cells stimulated proliferation by inducing G₁-S transition, suppression of cell apoptosis and promotion of tumor cell invasion and migration. Finally, OTUB1-isoform 2 overexpression promoted tumor growth and tumor metastasis in nude mice models.Conclusions: Our study suggests that OTUB1-isoform 2 independently predicts poor prognosis and promotes tumor progression in gastric cancer. The non-coding RNA OTUB1-isoform 2 should be targeted in future molecular therapies.