Aberrant LRP16 protein expression in primary neuroendocrine lung tumors

Background: The Leukemia related protein 16 gene (LRP16) localized on chromosome 11q12.1, is an important estrogen-responsive gene and a crucial regulator for NF-kB activation. LRP16 is frequently expressed in human cancers; however, the LRP16 gene remains unexplored in lung neuroendocrine tumors. The aim of this study was to investigate the role of LRP16 expression in primary lung neuroendocrine tumors. Methods: lung neuroendocrine tumors were analyzed for LRP16 gene expression by two-step non-biotin immunohistochemical method. Results: Fifty of ninety (55.6%) cases of neuroendocrine lung tumors tested were positive for LRP16 protein by immunohistochemistry. The expression of LRP16 was mainly located in cytoplasm and nucleus of tumor cells. LRP16 protein was corresponding to tumor type and clinical stage, as well as survival time. Conclusions: The results indicate that abnormal LRP16 expression is noted in neuroendocrine lung tumors and the expression can give insight into the pathogenesis of the disease. The LRP16 protein may serve as a potential marker in predicting prognosis of neuroendocrine lung tumors.     

E-cadherin-beta-catenin adhesion complex in neuroendocrine tumors of the lung: a suggested role upon local invasion and metastasis

Dysfunction or loss of the intercellular adhesion complex E-cadherin-beta-catenin is frequent in non-small cell lung carcinomas in which E-cadherin and beta-catenin loss has been considered to be a molecular marker of tumor progression and poor prognosis. With an aim of evaluating the expression of the E-cadherin-beta-catenin complex and its prognostic role in neuroendocrine tumors (NET) of the lung, immunohistochemical analysis was performed in 102 NET, including 16 low-grade typical carcinoids, 8 intermediate-grade atypical carcinoids, 37 large-cell neuroendocrine carcinomas (LCNEC), and 41 small-cell lung carcinomas, both high-grade tumors. Impaired E-cadherin expression (loss or cytoplasmic delocalization) was observed in 80 (78%) of 102 samples, and impaired beta-catenin expression was noted in 74 (72%) of 102 cases. The impaired expression of E-cadherin and beta-catenin was observed with a higher frequency in high-grade tumors (87% and 83%, respectively) than in carcinoids (50% and 37%, respectively; P < 0.0001). Impaired expression of the E-cadherin and beta-catenin molecules also correlated with lymph node metastasis (P = 0.0001 and P = 0.0005, respectively) and with advanced stage disease (P < 0.0001 for both factors). Moreover, impaired E-cadherin expression directly correlated with an extensive disease in carcinoids and in LCNEC (P = 0.02 and P = 0.04, respectively) and with node metastasis in LCNEC (P = 0.01). Levels of E-cadherin and beta-catenin were correlated with each other, consistent with an internal regulatory loop. Our results indicate that down-regulation of the E-cadherin-beta-catenin complex plays a role in NET progression.     

L1 cell adhesion molecule as a predictor for recurrence in pulmonary carcinoids and large‐cell neuroendocrine tumors

Pulmonary neuroendocrine tumors are a distinct subset of neoplasms with indolent to aggressive behavior. This study was conducted to evaluate the prognostic role of L1 cell adhesion molecule (L1CAM) in pulmonary neuroendocrine tumors. We retrospectively analyzed L1 expression in 55 cases of completely resected carcinoids and large‐cell neuroendocrine carcinomas, by the immunohistochemistry with monoclonal antibody A10‐A3 against human L1. L1 immunoreactivity was detected in 34 (61.8%) of 55 specimens. There was a significant correlation between L1 expression and the World Health Organization classification of this tumor (Spearman rank correlation, ρ=0.60, p<0.001). With median follow‐up of 52.0 months, the 5‐year survival rate for patients with low expression of L1 (<20% of tumor cells stained) was significantly better compared with those with high expression of L1 (82.6% vs. 43.7%, p=0.005). L1 was also a significant independent predictor of disease‐free survival, and patients with high L1 expression have a higher risk for recurrence compared with those with low L1 expression (hazard ratio, 3.0; 95% confidence interval, 1.2–8.3; p=0.034). L1 expression is significantly associated with aggressiveness and further studies with larger samples are needed to validate potential prognostic value for pulmonary neuroendocrine tumors.     

Molecular alterations of neuroendocrine tumours of the lung

Neuroendocrine tumours of the lung comprise low [typical carcinoid (TC)], intermediate [atypical carcinoid (AC)] and high‐grade [small‐cell lung cancer (SCLC) and large‐cell neuroendocrine carcinoma (LCNEC)] malignancies, while a pre‐invasive lesion [diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH)] may generate a subset of peripheral carcinoid tumours. These neoplasms are differentiated conventionally based on mitotic rate, presence of necrosis and cytological details, according to the 2015 World Health Organisation (WHO) classification. Clinical data and molecular alterations distinguish carcinoids and high‐grade carcinomas into two separate categories. Previous studies have demonstrated a significantly higher rate of chromosomal aberrations in carcinomas (e.g. 3p and 17p deletions), but restriction of multiple endocrine neoplasia type 1 (MEN1) mutations to carcinoids. High‐grade carcinomas are also characterised by TP53 and RB1 gene inactivation. In this review, a critical analysis of the diagnostic and prognostic role of Ki67 labelling index and a concise discussion of the most relevant findings regarding molecular characterisation of lung neuroendocrine neoplasms are reported. In addition, we illustrate how the development of promising therapeutic strategies based on the identification of molecular targets (mTOR inhibitors in carcinoids and targeting of the Notch ligand DLL3 in SCLC) may require the assessment of predictive biomarkers, even in the group of neuroendocrine tumours of the lung.     

Expression of aldo-keto reductase family 1 member C3 (AKR1C3) in neuroendocrine tumors & adenocarcinomas of pancreas,gastrointestinal tract,and lung

Human aldo-keto reductase family 1 member C3 (AKR1C3) was initially identified as an enzyme in reducing 5α-dihydrotestosterone (5α-DHT) to 5α-androstane-3α, 17β-diol (3α-diol) and oxidizing 3α-diol to androsterone. It was subsequently demonstrated to possess ketosteroid reductase activity in metabolizing other steroids including estrogen and progesterone, 11-ketoprostaglandin reductase activity in metabolizing prostaglandins, and dihydrodiol dehydrogenase x (DDx) activity in metabolizing xenobiotics. AKR1C3 was demonstrated in sex hormone-dependent tissues including testis, breast, endometrium, and prostate; in sex hormone-independent tissues including kidney and urothelium. Our previous study described the expression of AKR1C3 in squamous cell carcinoma and adenocarcinoma but not in small cell carcinoma. In this report, we studied the expression of AKR1C3 in normal tissue, adenocarcinomas (43 cases) and neuroendocrine (NE) tumors (40 cases) arising from the aerodigestive tract and pancreas. We demonstrated wide expression of AKR1C3 in superficially located mucosal cells, but not in NE cells. AKR1C3-positive immunoreactivity was detected in 38 cases (88.4%) of adenocarcinoma, but only in 7 cases (17.5%) of NE tumors in all cases. All NE tumors arising from the pancreas and appendix and most tumors from the colon and lung were negative. The highest ratio of positive AKR1C3 in NE tumors was found in tumors arising from the small intestine (50%). These results raise the question of AKR1C3’s role in the biology of normal mucosal epithelia and tumors. In addition, AKR1C3 may be a useful adjunct marker for the exclusion of the NE phenotype in diagnostic pathology.     

肾脏原发性神经内分泌肿瘤4例临床病理学观察

目的探讨肾脏原发性神经内分泌肿瘤(primary renal neuroendocrine tumors,PRNET)的临床病理学特征。方法对4例PRNET切除标本行HE染色、免疫组化染色,电镜下观察其形态结构、免疫表型及超微结构特点,并复习相关文献。结果4例PRNET中3例男性,1例女性;年龄39~73岁,平均50岁。2例PRNET因腰背部疼痛就诊,2例PRNET患者体检发现入院。4例PRNET镜下结构相似,肿瘤细胞呈管状、条带状紧密排列生长,部分呈巢、团状;肿瘤细胞规则一致,核深染,染色质细腻,核仁不易见,核分裂象均﹤3个/10 HPF。免疫表型:4例Syn均呈强阳性,2例Cg A呈阳性,2例CKpan呈局灶阳性,1例P504S呈阳性;CD10、CD117、PAX2、PAX8、PLAP、Ksp-cadherin均阴性;Ki-67增殖指数1%~5%。1例PRNET于电镜下见胞质内有大量神经内分泌颗粒,细胞间有桥粒连接。结论 PRNET是一种罕见的肾脏肿瘤,可发生于肾脏任何部位,无明显性别差异。诊断多依靠病理学检查,并结合免疫表型,必要时辅助电镜技术以明确诊断。     

hASH1基因与肺神经内分泌肿瘤的关系

肺神经内分泌肿瘤(neuroendocrine tumor，NET)是由具有多向分化潜能的肿瘤细胞组成，这些肿瘤细胞具有分泌多种活性激素的功能。肺NET的发生、发展与hASH1(human achaete-scute homologue 1), MEN1(multiple endocrine neoplasia type 1), pRB和E2F1等基因相关，其中hASH1基因成为近年来研究的热点，该基因能促进肺NET的内分泌分化，降低肿瘤的分化程度，并且有临床资料显示hASH1基因的表达还与小细胞肺癌的低生存率有关，可以作为临床预后的一个标准。     

肺神经内分泌肿瘤中INSM1的表达及其临床意义

目的探讨胰岛素瘤相关蛋白1(insulinoma-associated protein 1,INSM1)在肺神经内分泌肿瘤中的表达及其在鉴别诊断中的意义。方法采用免疫组化EnVision两步法检测INSM1、Syn、CgA、CD56在肺小细胞癌(26例)、肺大细胞神经内分泌癌(23例)、肺类癌(23例)、肺腺癌(72例)及肺鳞癌(52例)中的表达。结果(1)INSM1在神经内分泌肿瘤中的总阳性率为87.5%,显著高于肺腺癌(2.8%)和肺鳞癌(1.9%)(P<0.0001)。(2)INSM1在肺小细胞癌和大细胞神经内分泌癌中的敏感性分别为88.5%和78.3%,与Syn(88.5%和82.6%)及CD56(88.5%和78.3%)相似,显著高于CgA(57.7%和39.1%)(P<0.0001);INSM1在肺类癌中的敏感性为95.6%,与传统的神经内分泌免疫组化标志物(Syn、CgA、CD56)相似(P>0.999)。(3)INSM1在肺腺癌和肺鳞癌中的阳性率分别为2.8%和1.9%,与Syn和CgA相比差异无显著性(P>0.05),显著高于CD56(P<0.05)。(4)在37℃1 h孵育一抗,INSM1在小细胞癌、大细胞神经内分泌癌和肺类癌中的阳性率分别为84.6%、52.2%和30%;在4℃孵育一抗过夜,INSM1在三者中的阳性率分别为88.5%、78.3%和95.6%;一抗在4℃孵育过夜条件下,INSM1阳性率均高于37℃1 h的孵育条件。在4℃过夜和37℃1 h两种不同孵育条件下,小细胞癌的检测结果一致性为0.8354,大细胞神经内分泌癌为0.2868,肺类癌为0.0390。结论INSM1是肺神经内分泌肿瘤比较可靠的标志物,在4℃过夜条件下孵育一抗的检测结果比较可信。     

非小细胞肺癌中凋亡相关蛋白与伴神经内分泌分化表达的相关性

目的 检测非小细胞肺癌(non-small cell lung carcinoma,NSCLC)中凋亡相关蛋白与神经内分泌(neuroendocrine,NE)分化的表达,探讨其相关性.方法 采用免疫组织化学染色方法,检测NSCLC组织中survivin,bcl-2蛋白与NSE、Syn及CgA等蛋白的表达,并进行相关性作统计学分析.结果 113例NSCLC中,survivin、bcl-2阳性表达率分别为88.5%、58.4%;NSE、Syn和CgA蛋白阳性表达率分别为53.6%、6.2%和26.5%.伴NE分化者占21.2%,其survivin蛋白表达明显高于不伴NE分化组,差异有统计学意义.结论survivin、bcl-2蛋白表达上调可能在NSCLC发生发展中起重要作用.伴NE分化的NSCLC与表达阴性者相比,以survivin为代表的抗凋亡能力明显增强.     

Neuroendocrine marker expression in thyroid epithelial tumors

Tissue sections from 50 cases with thyroid tumors, composed of 11 follicular adenomas, 10 follicular carcinomas, 14 papillary carcinomas, 10 anaplastic carcinomas, and 5 medullary carcinomas, were immunohistochemically analyzed for representative neuroendocrine markers. Immunoexpression ratios of these neuroendocrine markers were as follows: Follicular adenomas, neuron-specific enolase (NSE) 63.6%, synaptophysin (SynP) 45.5%, Leu7 27.3%, NCAM 45.5%, chromogranin A (CgA) 0%, SNAP25 0%; follicular carcinomas, NSE 90.0%, SynP 80.0%, Leu7 80.0%, NCAM 0%, CgA 0%, SNAP25 0%; papillary carcinomas, NSE 85.7%, SynP 78.6%, Leu7 100%, NCAM 7.0%, CgA 0%, SNAP25.0%; anaplastic carcinomas, NSE 10.0%, SynP 0%, Leu7 0%, NCAM 0%, CgA 0%, SNAP25 0%; medullary carcinomas, NSE 100%, SynP100%, Leu7 80.0%, NCAM 40.0%, CgA 100%, SNAP25 100%. The two follicular carcinomas, which were morphologically characterized by "insular" (or "alveolar") arrangements, showed distinct immunoexpression of NSE and SynP at the same time. By in situ hybridization (ISH), expression of mRNA for NSE was confirmed in cases with marked immunoexpression of NSE. Although no endocrine granules were found, our results suggested that a specific type of follicular carcinoma, i.e., insular variant, may be immaturely neuroendocrine-differentiated.     

非小细胞肺癌生物学特性与神经内分泌分化的关系

目的：探讨非小细胞肺癌神经内分泌（neuroendocrine,NE)分化与肺癌生物学特性的关系。方法：采用免疫组化LSAB法检测有随访资料（8年）的53例非小细胞肺癌（non small cell lung carcinoma,NSCLC)神经内分泌标志。结果：NSCLC表达NSE、S－100蛋白、chromogranin A(CgA)和synaptophysin(Syn)阳性率分别为28．3％（15／53）、66．7％（39．53）、0／53和3．8％（2／53）。NSCLC伴NE分化与瘤体分期（Tstage)、治疗后肿瘤易复发和转移相关；有淋巴结转移的NSCLC患者3年和5年生存率低。结论：部分NSCLC伴NE分化，伴NE分化的NSCLC瘤体分期高、经综合治疗后肿瘤易复发和转移。有淋巴结转移的NSCLC患者预后差。     

LKB1基因转染对人肺腺癌细胞生物学行为的影响

目的:探讨外源性LKB1基因表达对人肺腺癌细胞生物学行为的影响。方法:应用巢式PCR方法扩增LKB1基因编码区,利用脂质体转染技术将真核表达重组体pcDNA-LKB1质粒和空载体pcDNA3.1质粒分别导入A549细胞,经G418筛选后获得稳定转染细胞克隆,Western blot检测LKB1和STAT3在A549细胞中的表达变化。通过绘制生长曲线和克隆形成试验检测获得性表达LKB1基因后肺癌细胞的增殖变化,流式细胞术(FCM)分析其细胞周期及其凋亡的变化。结果:成功获得了稳定表达外源性LKB1基因的A549细胞系,与转染空白载体组比较,转染LKB1基因的细胞生长速度明显减慢,细胞周期中G1/G0期比例明显增加,S期比例减少,细胞凋亡率升高;同时STAT3蛋白的磷酸化水平明显降低。结论:LKB1可能通过下调STAT3蛋白磷酸化水平的表达从而抑制A549细胞的恶性生物学行为。     

Frequent mutations in the neurotrophic tyrosine receptor kinase gene family in large cell neuroendocrine carcinoma of the lung

The neurotrophic tyrosine receptor kinase (NTRK) family is potentially implicated in tumorigenesis and progression of several neoplastic diseases, including lung cancer. We investigated a large number of pulmonary neuroendocrine tumors (PNETs) and non-small cell lung carcinomas (NSCLCs) without morphological evidence of neuroendocrine differentiation for mutations in the NTRK gene family. A total of 538 primary lung carcinomas, including 17 typical carcinoids (TCs), 10 atypical carcinoids (ACs), 39 small cell lung carcinomas (SCLCs), 29 large cell neuroendocrine carcinomas (LCNECs), and 443 NSCLCs were evaluated by single-strand conformation polymorphism (SSCP) and sequencing of the tyrosine kinase domain (TKD) of NTRK1, NTRK2, and NTRK3. The NTRK1 gene was never found to be mutated. A total of 10 somatic mutations were detected in NTRK2 and NTRK3, mostly located in the activating and catalytic loops. NTRK mutations were seen in 9 (10%) out of 95 PNETs but in 0 out of 443 NSCLCs investigated. No mutations were observed in TCs, ACs, and SCLCs. Interestingly, all the mutations were restricted to the LCNEC histotype, in which they accounted for 31% of cases. A mutational analysis, performed after microdissection of LCNECs combined with adenocarcinoma (ADC), showed that only neuroendocrine areas were positive, suggesting that NTRK mutations are involved in the genesis of the neuroendocrine component of combined LCNECs. Our data indicate that somatic mutations in the TKD of NTRK genes are frequent in LCNECs. Such mutational events could represent an important step in the cancerogenesis of these tumors and may have potential implications for the selection of patients for targeted therapy.     

MEN1 gene mutations in sporadic neuroendocrine tumors of foregut derivation

Foregut-derived neuroendocrine (NE) tumors occur sporadically or in association with multiple endocrine neoplasia type 1 (MEN1) syndrome. Thirty-nine sporadic NE tumors of foregut derivation (six thymic, 21 bronchial, three gastric, and nine pancreatic tumors) as well as two hindgut-derived rectal carcinoids for somatic MEN1 gene mutation were analyzed by direct sequencing analysis. Five tumors showed mutations: nonsense mutations (Q393X and R98X) in thymic and pancreatic NE tumors, respectively, a 4 b.p. deletion (357del4) in a gastric NE carcinoma, and missense mutations (D172Y and S178Y) in pancreatic NE tumors. No mutation was identified in pulmonary or rectal NE tumors. In a patient with a pancreatic NE tumor (D172Y), the corresponding germline DNA showed the same mutation, suggesting that sporadic MEN1 syndrome was masked in this case. Somatic MEN1 gene mutations and deletions may play a crucial role in the tumorigenesis of a subset of foregut-derived NE tumors. Sporadic MEN1 syndrome may occur as a sporadic NE tumor of the pancreas.     

结肠癌组织中LKB1的表达及其与上皮-间质转化的关系

目的探讨LKB1在结肠癌组织中的表达及其与肿瘤上皮-间质转化的关系。方法采用免疫组化法检测75例结肠癌组织及对应癌旁正常结肠组织中LKB1、上皮-间质转化(epithelial mesenchymal transformation,EMT)相关标志物E-cadherin、N-cadherin、vimentin的表达,分析LKB1表达与结肠癌临床病理特征及EMT的关系。结果 49例结肠癌组织中LKB1低表达,55例正常结肠组织中LKB1高表达;LKB1表达降低与淋巴结转移、TNM肿瘤分期相关(P0.05);E-cadherin、N-cadherin、vimentin分别在25例、48例、26例结肠癌组织中高表达,LKB1表达与E-cadherin表达呈正相关(r=0.648,P0.05),与Ncadherin(r=-0.891,P0.05)和vimentin(r=-0.660,P0.05)表达呈负相关。结论 LKB1在结肠癌组织中表达下调,与EMT的发生呈正相关,可作为结肠癌转移发生的预测指标。     

Comparing of IRS and Her2 as immunohistochemical scoring schemes in gastroenteropancreatic neuroendocrine tumors

Neuroendocrine tumors (NET) are known for an overexpression of somatostatin receptors (SSTR). In light of very few and partially contradictory publications, the present study aims to achieve a definite immunohistochemical (IHC) quantification and assessment of the distribution of all five SSTR-subtypes on NET and to evaluate an implementable scoring system, comparing the immunoreactive score of Remmele and Stegner (IRS) to the Her2-score. In 21 patients 40 different tumor tissues were IHC analysed using polyclonal antibodies for SSTR1 and 3-5 and the monoclonal antibody UMB-1 for SSTR2A. SSTR expression was quantitatively evaluated according to HER2-score and IRS, correlated among each other and to the maximum standardized uptake value (SUVmax) in tumor lesions as measured by PET/CT using 68Ga-DOTA-NOC. RESULTS: According to the IRS, the expression of SSTR2A and 3 predominated equally with 84%, followed by SSTR4 (44%) and SSTR1 and 5 (32%). With the Her2-scoring system the most frequent subtype was found to be SSTR2A (68%), followed by SSTR3 (64%), SSTR1 (44%), SSTR5 (40%), and SSTR4 (36%). The IRS-classification and the Her2-score were found to be statistically comparable, and their correlation is highly significant for each SSTR assessment (p<0.01). CONCLUSION: The results of the analyses revealed heterogeneous expression patterns. SSTR2A and 3 were highly expressed, demonstrating the importance of SSTR for diagnostics and therapy. Relatively high frequency of SSTR3 and 4 on NET give reasons to try pansomatostatin analogues for therapy rather than concentrating only on the SSTR2A. Statistically, none of the immunohistochemical scores was superior. However, due the heterogeneity of the cytoplasmic staining justice we propose the IRS as a uniform scoring scheme for IHC NET diagnostic.     

Specific pattern of LKB1 and phospho-acetyl-CoA carboxylase protein immunostaining in human normal tissues and lung carcinomas

The LKB1 tumor suppressor gene codes for a serine/threonine protein kinase, and among its substrates is the adenosine monophosphate-dependent protein kinase, a sensor of intracellular energy levels. LKB1 is genetically inactivated in several types of tumors, especially lung adenocarcinomas. Here we used immunohistochemistry to evaluate the levels of LKB1 and the phosphorylated form of the acetyl-CoA carboxylase (ACC) protein in a variety of human adult normal tissues and in 159 lung carcinomas. The enzyme ACC becomes inactive upon phosphorylation by adenosine monophosphate-dependent protein kinase. Our analysis in normal tissues revealed strong LKB1 immunostaining in most epithelia, in the seminiferous tubules of the testis, in myocytes from skeletal muscle, and in glia cells. In contrast to the cytosolic location of LKB1 found in most tissues, glia cells carried mainly nuclear LKB1. Some epithelial cells showed apical accumulation of LKB1, supporting its role in cell polarity. Regarding phospho-ACC (p-ACC), strong immunostaining was observed in myocytes from the skeletal muscle and heart, and in Leydig cells of the testis. In lung tumors, LKB1 immunostaining was absent, moderate, and high in 20%, 61%, and 19% of the tumors, respectively, whereas p-ACC immunostaining was found to be absent/low, moderate, and high in 35%, 34%, and 31% of the tumors, respectively. High levels of LKB1 and p-ACC immunostaining predominated in lung adenocarcinomas compared with squamous cell carcinomas. Finally, high p-ACC was an independent marker for prediction of better survival in lung adenocarcinoma patients. Median overall survival was longer in patients with p-ACC-positive than those with p-ACC-negative tumors (96 versus 44 months, P = .04). In conclusion, our observations provide complete information about the pattern and levels of LKB1 and p-ACC immunostaining in normal tissues and in lung tumors, and highlight the special relevance of abnormalities of the LKB1 pathway in lung adenocarcinoma.     

胃肠胰食管神经内分泌肿瘤中NKX2．2蛋白的表达

目的：检测NKX2．2蛋白在胃肠胰食管神经内分泌肿瘤中的表达,探讨其表达与临床病理特征的关系。方法采用免疫组化法检测41例胃肠胰食管神经内分泌肿瘤中NKX2．2、Syn及CgA的表达,并复习相关文献。结果 NKX2．2蛋白阳性定位于细胞核,在7个原发部位的神经内分泌肿瘤中均有不同程度的表达,在4例正常胰腺胰岛细胞中弥漫强阳性表达, NKX2．2、Syn及CgA在小肠、直肠及胰腺神经内分泌肿瘤中的总阳性率分别为100%、100%、46．7%;NKX2．2在前肠、中后肠的阳性率分别为30%和87%,差异有统计学意义(χ2=11．09,P=0．001)。 NKX2．2蛋白表达与患者性别、年龄、分级、肿瘤最大径及淋巴结转移无明显相关性。结论 NKX2．2作为一种新型的神经内分泌标志物,在诊断小肠、直肠及胰腺神经内分泌肿瘤上明显优于CgA,联合检测NKX2．2、Syn、CgA可提高小肠、直肠及胰腺神经内分泌肿瘤诊断的准确性。     

High-grade neuroendocrine carcinomas of the lung express K homology domain containing protein overexpressed in cancer but carcinoid tumors do not

K homology domain containing protein overexpressed in cancer (KOC) is a member of the insulin-like growth factor (IGF) messenger RNA-binding protein family and is expressed during embryogenesis and in certain malignancies. KOC, known as L523S and IGF messenger RNA-binding protein 3, was shown to be frequently expressed in high-grade neuroendocrine carcinomas of the lung in our immunohistochemical studies using a monoclonal antibody against human KOC. Specifically, all 10 small cell lung carcinomas (SCLCs) exhibited strong cytoplasmic staining, 9 with diffuse positivity and 1 with focal positivity. Among 14 large cell neuroendocrine carcinomas (LCNECs), 9 exhibited strong and diffuse cytoplasmic staining, and 5 cases showed focal immunoreactivity. In contrast, no KOC was detected in 21 typical and atypical carcinoids, except for one atypical carcinoid with oncocytic cells showing weak cytoplasmic staining. Although SCLCs exhibited a strong and diffuse staining pattern more frequently (90%) than LCNECs (64%), the difference did not reach statistical significance (P = .3408). Interestingly, our immunohistochemical studies demonstrated that IGF-II, reportedly regulated by KOC, was comparably expressed in SCLC, LCNEC, and typical and atypical carcinoids, irrespective of KOC expression status of the tumors. These results support the formulation that KOC may play an important role in the regulation of biologic behavior of high-grade neuroendocrine carcinomas. In addition, detection of KOC expression may be diagnostically useful in distinguishing high-grade neuroendocrine carcinomas from carcinoid tumors. Our findings of equivalent IGF-II expression in KOC-positive SCLC and LCNEC and KOC-negative carcinoid tumors suggest different regulatory mechanisms involved in the control of IGF-II expression in these tumors.