Expressions of oncogenes c-fos and c-myc in skin lesion of cutaneous squamous cell carcinoma

Objective:To explore the expressions of c-fos and c-myc in skin lesion of cutaneous squamous cell carcinoma(CSCC).Methods:Using retrospective analysis.73 cases of CSCC were selected from Department of Dermatology,the Second Affiliated Hospital of Xi'an Jiaotong University.which were removed between January 2000 and January 2012.It was considered as experimental group.Meanwhile.11 cases of normal skin specimens of non tumor patients were selected as control group.The expression level of c-fos and c-myc was compared in the two groups.Results:The expressions of c-fos[72.60%(53/73)]and c-myc[83.56%(61/73)]in experimental group were statistically significant(P≤0.05)compared with control group(0%).Expression of c-myc protein was negatively related to differentiation of CSCC.The difference was statistically significant(X^2=7.26.P=0.001<0.05).While expression of c-fos protein was positively related to differentiation of CSCC.which was statistically significant(X^2=7.47,P=0.0012<0.025).Conclusions:The expression level of c-fos and c-myc can be used as an importan indicator of CSCC differentiation,and it has closely connection with the differentiated degree,which can guide clinical prognosis.

THE RELATIONSHIP BETWEEN EXPRESSIONS OF N-myc AND c-myc ONCOGENES IN NEUROBLASTOMA:AN IN SITU HYBRIDIZATION AND IMMUNOCYTOCHEMICAL STUDY

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A STUDY OF C-MYC ONCOGENE EXPRESSION AND AMPLIFICATION IN COLORECTAL CANCER

Expression of c-myc oncogene transcripts in colorectal neoplasia was studied in paraffin embedded tissue sections from 25 patients undergoing surgery and from the rectal carcinoma cell line HR-8348 by using in situ hybridization,and its amplification was investigated in tumor and normal mucosa tissue from 25 coloproctomy samples by slot blot hybridization. Overexpression of this gene was seen in 78% (7/9) of the benign adenomas and 91% (20/22) of the malignancies sampled. There was no significant correlation between overexpression and the histologic type or grade, and no significant relationship between the level of expression and clinical stage was found, although overexpression was apparently more common in tumors with metastasis. Amplification of the gene was found in 0 of 4 benign adenomas and 7 of 22 malignancies. No obvious correlation was found between amplification and histological type or grade, though amplification was more frequent in tumors with metastasis. Amplification was also found in 2 adenomas with malignant change. The results suggest that multiple factors are involved in the progression of colorectal cancer , and in situ hybridization with a nonradiolabeled probe is useful in the detection of gene expression.

Induction of Rat Prolactinoma by β－Estradiol and Its Relation to Expression of c－myc Oncogene

Sprague-Dawley rats were implanted with silastic capsules containing β-estradiol. After 60 days, their pituitary weights, serum prolactin contentsand transcription level of c-myc proto-oncogene were found increasedsignificantly. It was also found that the anterior pituitary cells proliferatedsignificantly, but their differentiation was suppressed.

DOWN－REGULATION OF C－MYC ONCOGENE DURING NGF－INDUCED DIFFERENTIATION OF NEUROBLASTOMA CELL LINES

There may be a close relationship between myc oncogenes and carcinogenesis of human neuroblastoma. In previous studies, we were able to induce differentiation of certain neuroblastoma cell lines with NGF. In order to study gene regulation during differentiation, N-myc and c-myc cDNA probe were hybridized with RNA extracted from different cell lines before and after NGF treatment. It was found that cell lines which expressed N-myc did not express c-myc while those with c-myc did not express N-myc except for SHEP cell line which had neither c-myc nor N-myc expression. In NGF-induced differentiated neuroblastoma cells, c-myc oncogene was down-regulated in comparison with the control samples. The time course of c-myc down-regulation was concomitant with the appearance of morphological differentiation. In situ hybridization also showed remarkable reduction of c-myc oncogene expression in NGF-induced differentiated cells as compared with the untreated control cells. These results indicate that down-regulation of c-myc oncogene may be a key event during NGF-induced differentiation and overexpression of c-myc oncogene may, at least partially, be responsible for the genesis of neuroblastoma.

Expressions of vascular endothelial growth factor in cirrhotic tissues and their relations to proto-oncogene c-fos, c-myc

Objective: To investigate the significance of vascular endothelial growth factor (VEGF) in the pathogene- sis of liver cirrhosis and the correlation between VEGF and proto-oncogene c-fos and c-myc in cir- rhotic liver. Methods: The proteins of VEGF, c-fos, and c-myc were identified immunohistochemically in each tissue section of 53 cases of liver cirrhosis. The correlations between VEGF, c-fos and c-myc were analyzed. The levels of VEGF protein in different Child gradings were also compared. Results: The proteins of VEGF were more highly ex- pressed in Child A and B patients than in Child C patients and controls. The expressions of both c-fos and c-myc were not statistically significant between VEGF positive and negative patients. Conclusions: The protein level of VEGF can reflect the compensation status of cirrhosis patients and may act as an anti-cirrhotic factor. The proto-oncogene c- fos, c-myc and VEGF may have different mecha- nisms in the course of cirrhosis or hepatic tumorigen- esis.

Study of differential polymerase chain reaction of C-erbB-2 oncogene amplification in gastric cancer

AIM To study the significance of C-erbB-2 oncogene amplification in gastric cancer.METHODS C-erbB-2 oncogene amplification was examined by using differential polymerase chain reaction (dPCR) in surgical and endoscopic specimens of 83 cases of gastric cancer and 101 metastatic lymph nodes.RESULTS C-erbB-2 amplification was found in 28.9% (24/ 83) surgical specimens and 20.5% (17/ 83) endoscopic ones of gastric cancer patients. The amplification was significant in both types of specimens of advanced cancer cases (P＜0.05) and surgical specimens with lymph node metastasis (P＜0.01). The incidence of C-erbB-2 amplification in lymph nodes with metastasis was higher than in primary sites (surgical specimens, P＜0.05). The patients with amplification tumors had poorer 5-year survival rates than those with unamplification ones in the early cancers and well to moderately differentiated adenocarcinomas (P＜0.05). The same surgical samples were tested again by Southern blot hybridization to ascertain C-erbB-2 amplification, and the positive rate of C-erbB-2 amplification (15.7%) was lower than that of dPCR (28.9%, P＜0.05).CONCLUSION Examining C-erbB-2 amplification by dPCR is a quick, simple, reliable and independent method, and is helpful in predicting prognosis and metastatic potential of gastric cancer.

MUTATION AND CLINICAL SIGNIFICANCE OF C-FMS ONCOGENE IN HEPATOCELLULAR CARCINOMA

Objective: To study the clinical significance and relationship between c-fms oncogene and hepatocellular carcinogenesis, to further clarify the occurring mechanism of hepatocellular carcinoma (HCC). Methods: PCR-SSCP technique was used to analyse mutation of c-fms oncogene in 30 cases of HCC tissues. Sequencing the PCR products after cloning to prove the mutations, meanwhile the relationship between c-fms mutations and clinical pathology of HCC was investigated. Results: Two abnormal single strands were observed in 10% (3/30) HCC tissues from c-fms DNA corresponding to 301st codon of c-fms amino acids. PCR products of abnormal single strands were sequenced after cloning, it demonstrated that there was transition of T→C at nucleic acid 14855 of c-fms DNA, which corresponded to transition of Leu (TTG)→Ser (TCG) at 301st codon of c-fms amino acids. The mutation was related to malignant degree and type of HCC tissues as well as patient’s age. Conclusion: Mutation of c-fms codon at site 301 implied a molecular mechanism contributing to hepatocellular carcinogenesis.

The relationship between point mutation and abnormal expression of c-fms oncogene in hepatocellular carcinoma

BACKGROUND: Recent research found abnormal expres- sion of the c-fms oncogene, which encodes the macro- phage colony-stimulating factor receptor (CSF-1R), in several human carcinomas including hepatocellular carcino- ma (HCC). But the relationship between the point muta- tion and abnormal expressing of c-fms oncogene in HCC was not clear. This study is to investigate the relationship between point mutation and abnormal expression of c-fms oncogene in hepatocellular carcinoma (HCC) and to clari- fy the mechanism of HCC. METHODS: The expression of c-fms oncogene at different levels of cell, protein and transcription was observed using immune histological ABC, Western blot and Northern blot. PCR-single strand conformation polymorphism and gene sequencing were used to detect the mutation of c-fms in HCC tissues and their surrounding tissues of 30 patients. RESULTS: The expression of c-fms was significantly higher in HCC tissues than in their surrounding tissues (P <0.01). Point mutation of Leu (TTG)—>Ser (TCG) at codon 301 of c-fms amino acids was observed in 21.4% (3/14) HCC tissues. No mutation of c-fms oncogene was detected in the surrounding cancerous tissues. CONCLUSION: Point mutation at codon 301 of c-fms on- cogene is one of the mechanisms of abnormal over-expres- sion in HCC.

Expression and distribution of c-fos oncogene within central nervous system of the rat following halothane anesthesia

Objective: To study the distribution of c fos oncogene expression within central nervous system (CNS) of the rat during halothane anesthesia. Methods: c-fos oncogene immunohistochemical technique (ABC method) was employed. Results: When halothane concentration was 0.75%,1.5%or2.0%, most of the Fos-like immunore- active neurons (FLNs) appeared in telencephalon, diencephalon and brain stem, including cerebral cortex, amygaloid nucleus, accumbens nucleus, lateral keptal nucleus. bed nucleus of the stria terminalis, field CA1 of Ammon’s horn, islands of Calleja, paraventricular thalamic nucleus, central medial thalamic nucleus, reuniens thalamic nucleus, rhomboid thalamic nucleus. ventral posterolateral thalamic nucleus, paraventricular hypothalamic nucleus(ventral part). periventricular hypothalamic nucleus, median preoptic nucleus, supraoptic nucleus, suprachiasmatic nucleus. medial and lateral habenular nucleus. midbrain periaqueductal gray and Edinger-Westphal nucleus.In the present stude. we have also found that the number of FLN registered stable increase along with the increaseof the concentration of halothane. Conclusion: It has been indicated that FLNs participate in the process ofhalothane anesthesia. which should necessitate and pave the way for a further study of the patterns of linkage andthe mechanism of interaction between functional nuclei.

Expressions of estrogen receptor subtypes and c-met proto-oncogene in endometrial carcinoma and their correlation

Objective To investigate the expressions of estrogen receptor(ER)subtypes and c-met proto-oncogene in human endometrial carcinomas and to assess the clinical significance of ER and c-met in this carcinoma.Methods Reverse transcription PCR(RT-PCR)was used to detect the expressions of ERα,ERβ and c-met proto-oncogene mRNA in 30 samples of endometrial carcinoma and 11 samples of normal endometrium.Results The expression of ERα in endometrial carcinoma(0.70±0.40)was significantly reduced in comparison to that in normal endometrium(1.14±0.56,P<0.05).A similar finding was made for the expression of ERβ in carcinoma(0.24±0.18)versus normal tissues(0.48±0.20,P<0.05).In contrast,c-met mRNA expression was increased in endometrial carcinoma(1.45±0.72)compared to that in normal endometrium(0.42±0.31,P<0.01).A decrease tendency of the expression of ERα was also found from Stage Ⅰ(0.82±0.41)to a more severe Stag Ⅱ-Ⅲ of endometrial carcinoma(0.42±0.17,P<0.05).The analysis of ERα and ERβ mRNA revealed a decrease tendency from shallow to deep invasion of the uterine muscles(P<0.05).We found that the expressions of ERα and ERβ were negatively correlated with c-met proto-oncogene with a coefficient correlation of-0.63(P<0.01)and-0.32(P<0.05),respectively.Conclusion ERα and ERβ are both involved in mutagenic action of carcinogen.C-met proto-oncogene plays an important role in the carcinogenesis and development of endometrial carcinoma.C-met and ER expressions show a negative correlation in the development of endometrial carcinoma.

Preliminary Study on c-Ha-ras Oncogene Mutations in Hydatidiform Mole Tissues

ve To study the presence of c-Ha-ras oncogene mutations in hydatidiform mole (HM) tissues and to further explore its relationship with mole's malignancy

A COMPARISON OF THE PROTOONCOGENES BETWEEN THE HUMAN GASTRIC CANCEROUS AND NORMAL MUCOSAL TISSUES

The allelic distribution of EcoRI and BamHI fragments of ras family genes between the human primary gastric cancer tissues and the corresponding adjacent normal tissues did not show any differences. Three genotypes of BamHI restriction fragment length polymorphism of c-H-ras were revealed. No significant differences in the RFLPs were observed between normal individuals and gastric cancer patients. Four protooncogenes, c-H-ras, N-ras, c-myc and c-fos, were found to be transcriptionally active in the gastric cancer tissues in some cases examined. The comparison of the expression of these oncogenes between the malignant tissues and the corresponding normal tissues showed differential patterns. The expression of c-H-ras at cellular level was detected by in situ hybridization. The enhanced expression of c-H-ras in the gastric cancer cells was demonstrated, but the degree of the expression among the cancer cells was shown to be heterogeneous. In addition, the enhanced expression of c-H-ras was seen in the inflammatory cells.

IMMUNOHISTOCHEMICAL LOCALIZATION OF EPIDERMAL GROWTH FACTOR RECEPTOR AND C-erbB-2 ONCOGENE PRODUCT IN DEVELOPING HUMAN PLACENTA

Cytologic locailzation of epidermai growth factor receptor (EGF-R) and C-erbB2oncogene product in normal developing placenta ovas studied by avidin/biotin immunoperoxidase techniques.Both proteins were predominantly expressed in the villous syncytiotrophoblasts but not in the cytotrophoblasts.The immunoreactive intensity for EGF-R decreased with the development of pregnancy.Concerning the intermediate trophoblasts in cell islands and cell columns,both proteins were more easily detected in the cells distal to the villous stroma than in the juxtastromal cells.These findings suggest that EGF-R and C-erbB-2 may play a significant role in the induction and regulation of differentiated trophoblast function

Detection of Tumor Suppressor Gene and Oncogene in SO-Rb_(50) Human Retinoblastoma Cell Line

Retinoblastoma (Rb) is the most common malignant'cancer of eye.So-Rb_(50) is the first Rb cell line established in China in 1988.It has passed to the 387th passage now.We collected cells of the 327th passage of SO-Rb_(50),purified its genomic DNA and detected it with Rb and c-myc cDNA probes respectively(normal human white blood cells DNA was the control).We found the Rb gene was deleted while c-myc gene was amplified three times.This provides a basis for further study of the regulation of tumor development and tumor reversal with this cell line in vitro.Eye Science 1993;9:34-37.

c-Myc、CDK12在胃癌组织中的表达及临床意义

目的 探讨胃癌组织中c-Myc、细胞周期蛋白依赖性激酶12(CDK12)表达及其与患者临床特征及预后的关系。方法 收集80例胃癌患者的胃癌组织和癌旁组织标本,采用免疫组化法检测标本中的c-Myc、CDK12表达水平。比较胃癌组织和癌旁组织中c-Myc、CDK12阳性表达情况;分析胃癌组织中c-Myc、CDK12阳性表达与患者临床病理特征的关系;分析c-Myc与CDK12阳性表达的相关性,胃癌组织中c-Myc、CDK12阳性表达与胃癌患者预后的关系。结果 胃癌组织中c-Myc、CDK12阳性表达率(77.5%、87.5%)均明显高于癌旁组织(13.8%、15.0%)(P<0.05)。不同年龄、性别、肿瘤最大直径患者胃癌组织中c-Myc、CDK12阳性表达率比较差异无统计学意义(P>0.05);中低分化、Ⅲ~Ⅳ期、侵犯浆膜、有淋巴结转移患者胃癌组织中c-Myc和CDK12阳性表达率分别为88.0%、87.0%、88.9%、90.0%和94.0%、92.6%、97.2%、100.0%,均明显高于高分化、Ⅰ~Ⅱ期、未侵犯浆膜、无淋巴结转移患者胃癌组织的60.0%、57.7%、68.2%、70.0%和76.7%、76.9%、79.5%、80.0%(P<0.05)。相关分析发现,c-Myc、CDK12在胃癌组织中的表达呈正相关性(r=0.487,P=0.016<0.05)。胃癌组织中c-Myc、CDK12阳性患者的3年生存率分别为19.4%、21.4%,均明显低于c-Myc、CDK12阴性患者的55.6%、70.0%(P<0.05)。结论 c-Myc、CDK12在胃癌组织中异常高表达,两者呈正相关性,并与肿瘤的TNM分期、分化程度、肿瘤侵袭深度及淋巴结转移有关,对患者的预后有明显影响,通过检测两者水平可能评估胃癌患者的预后。

胃癌模型大鼠胃黏膜组织Cyclin D1、c-Myc、CKIT的表达意义及其与胃癌病变程度的相关性

目的探讨胃癌模型大鼠胃黏膜组织细胞周期蛋白D1(cyclinD1)、c-Myc、CKIT的表达意义及其与胃癌病变程度的相关性。方法选择48只健康成年雌性大鼠,按照随机数字表法将其分为对照组、研究1组、研究2组、研究3组,每组各12只。研究1组、研究2组、研究3组均制备成胃癌模型。对照组给予等量0.9%氯化钠溶液,第24周处死取材;研究1组、研究2组、研究3组制备成胃癌大鼠后分别于第8、16、24周取材。分析各组大鼠一般情况及胃黏膜组织病理切片,采用蛋白质印迹法检测胃黏膜组织Cyclin D1、c-Myc、CKIT蛋白的表达,采用逆转录聚合酶链式反应(RT-PCR)法测定胃黏膜组织Cyclin D1、c-Myc、CKIT mRNA的表达,采用Spearman分析法测定胃黏膜组织Cyclin D1、c-Myc、CKIT表达与胃癌病变程度相关性。结果对照组大鼠胃黏膜完整正常,外膜层、肌层、黏膜下层、黏膜层等结构清晰,且无炎症细胞浸润;研究1组大鼠胃黏膜组织与对照组大鼠接近,不存在炎症细胞,且黏膜腺体结构基本正常;研究2组大鼠胃黏膜组织存在破损,细胞核变大,基底部部分腺体细胞形态异常,存在轻度异型性,为早期胃癌;研究3组大鼠胃黏膜组织增加破损,核质比变大,细胞形态不规则,部分腺体存在扩张,黏膜下层及肌层存在炎症细胞浸润,为胃癌进展期。研究1组、研究2组、研究3组胃黏膜组织Cyclin D1、c-Myc、CKIT蛋白均呈显著高于对照组,差异均有统计学意义(P<0.05),胃黏膜组织Cyclin D1、c-Myc、CKIT蛋白在研究1组、研究2组、研究3组中逐渐升高趋势。研究1组、研究2组、研究3组胃黏膜组织Cyclin D1、c-Myc、CKIT mRNA均呈显著高于对照组,差异均有统计学意义(P<0.05),胃黏膜组织Cyclin D1、c-Myc、CKIT mRNA在研究1组、研究2组、研究3组中逐渐升高趋势。采用Spearman相关性结果分析显示,胃黏膜组织Cyclin D1、c-Myc、CKIT表达与胃癌病变程度呈正相关(r=0.382、0.781、0.993,均P<0.001)。结论胃癌模型大鼠胃黏膜组织Cyclin D1、c-Myc、CKIT呈高表达,其与胃癌病变程度密切相关。

Reduction of mitomycin C resistance in human bladder cancer T24 cells by knocking-down ras oncogene

Aim:Mitomycin C(MMC)is a commonly used as intravesical treatment for superficial bladder cancer.However,its role in combination with ras inhibition has not been investigated.The aim of this study was to explore the role of ras in MMC-induced apoptosis in T24 bladder cancer cells and to determine the efficacy of combination therapy in vitro.Methods:We measured the effects of various doses of MMC on apoptosis induction as well as on ras,ERK and Ki-67 protein expression by T24 cell line using immunocytochemistry,flow cytometry and Western blotting.We also tested the effect of siRNA on ras employed singly or in combination with MMC.Results:T24 cells expressed high level of ras protein.MMC treatment increased the level of ras and ERK protein expression after 24 h,and decreased these levels after 72 h.Ras siRNA(100 nmol/L)caused massive apoptosis associated with a marked decrease in ras expression in T24 cells.When combined with low doses of MMC,ras siRNA(50 nmol/L)sensitized T24 cells to apoptosis and decreased their expression of ras.The effect of combined therapy was higher than that of either compound used alone.Expression levels of ERK,a downstream target of ras,declined following combination therapy.Conclusion:Ras siRNA in combination with low dose MMC is a possible treatment strategy for patients with ras-positive bladder tumors.

华蟾素通过调控MYH9/USP7/c-MYC通路抑制急性髓系白血病细胞免疫逃逸

【目的】探讨华蟾素调控肌球蛋白重链9(MYH9)/泛素特异性蛋白酶7(USP7)/骨髓细胞瘤病毒癌基因(c-MYC)通路对急性髓系白血病(AML)细胞免疫逃逸的影响。【方法】(1)体内实验:建立裸鼠异种移植瘤模型,评估华蟾素对AML细胞在体内生长和免疫逃逸的影响。(2)体外实验:使用不同浓度的华蟾素处理人AML细胞株HL-60,细胞计数试剂盒8(CCK-8)法检测细胞活力,Transwell实验检测细胞侵袭能力。将HL-60细胞与活化的CD8^(+)T细胞共培养,流式细胞术检测CD8^(+)T细胞表面标志物CD25的表达,酶联免疫吸附分析(ELISA)检测共培养上清液中细胞因子[白细胞介素2(IL-2)和干扰素(IFN-γ)]的水平,CytoTox96非放射性细胞毒性分析评估CD8^(+)T细胞对HL-60细胞的毒性。Western Blot法检测MYH9、USP7和c-MYC的蛋白表达,免疫共沉淀(Co-IP)法检测MYH9、USP7和泛素化之间的相互作用。转染MYH9过表质粒,验证华蟾素在AML中的作用机制。【结果】华蟾素抑制裸鼠移植瘤生长,增强CD8^(+)T细胞抗肿瘤的能力。华蟾素浓度依赖性地抑制HL-60细胞活力、侵袭。华蟾素处理后上调CD8^(+)T细胞表面标志物CD25的表达,同时还上调IL-2和IFN-γ水平。华蟾素增强CD8^(+)T细胞对HL-60细胞的毒性。华蟾素抑制HL-60细胞MYH9、USP7和c-MYC的蛋白表达,MYH9通过募集USP7促进c-MYC去泛素化,华蟾素抑制MYH9介导的c-MYC去泛素化。【结论】华蟾素可通过抑制MYH9的表达进而减少去泛素化酶USP7对c-MYC的募集,促进c-MYC泛素化降解,从而抑制AML细胞免疫逃逸。

鳜弹状病毒N蛋白与鳜c-Myc互作调控谷氨酰胺代谢机制

为了研究鳜弹状病毒(SCRV)如何调控鳜c-Myc(Sc-c-Myc)进而调控谷氨酰胺代谢的分子机制,本研究通过免疫共沉淀联合蛋白质谱寻找可能与Sc-c-Myc互作的病毒蛋白,初步分析确定为核衣壳蛋白(N蛋白);Co-IP结果显示,SCRV的N蛋白与Sc-c-Myc存在相互作用。通过PCR扩增获得了带有Flag标签序列的SCRV-N基因的ORF片段,并构建了SCRV-N蛋白过表达载体pcDNA-N-Flag;将pcDNA-N-Flag质粒转染鳜脑组织细胞系(CPB细胞系),荧光共定位结果显示,Sc-c-Myc与SCRV-N在细胞质内存在共定位现象;通过逆转录实时定量PCR(RT-qPCR)和免疫印记(Western blot)检测转染pcDNA-N-Flag的CPB细胞系中Sc-c-Myc及谷氨酰胺代谢通路关键酶(GLS1、GDH和IDH2)的表达变化,发现Sc-c-Myc、GLS1的转录水平和蛋白水平均显著上调。综上表明,SCRV的N蛋白与Sc-c-Myc互作促进Sc-c-Myc的表达,进而调控宿主细胞谷氨酰胺代谢途径,为SCRV防控提供了新的靶点。