Aberrant methylation of secreted protein acidic and rich in cysteine gene and its significance in gastric cancer

BACKGROUND Aberrant methylation in DNA regulatory regions could downregulate tumor suppressor genes without changing the sequences.However,our knowledge of secreted protein acidic and rich in cysteine(SPARC)and its aberrant methylation in gastric cancer(GC)is still inadequate.In the present research,we performed fundamental research to clarify the precise function of methylation on SPARC and its significance in GC.AIM To investigate promoter methylation and the effects of the SPARC gene in GC cells and tissues and to evaluate its clinical significance.METHODS Plasmids that overexpressed the SPARC gene were transfected into human GC BGC-823 cells;non-transfected cells were used as a control group(NC group).Quantitative real-time polymerase chain reaction and western blotting(WB)were then used to detect the expression of SPARC.Methylation-specific polymerase chain reaction was executed to analyze the gene promoter methylation status.Cell viability was measured by the cell counting kit-8 assay.The migration and invasion ability of cells were detected by scratch assays and transwell chamber assays,respectively.Cell cycle events and apoptosis were observed with a flow cytometer.RESULTS The expression of SPARC mRNA in GC tissues and cells was significantly lower and showed differing degrees of hypermethylation,respectively,than that in normal adjacent tissues and control cells.Treatment with 5-Aza-2’-deoxycytidine(5-Aza-Cdr)was able to restore the expression of SPARC and reverse promoter hypermethylation.Overexpression of the SPARC gene significantly inhibited proliferation,migration,and invasion of GC cells,while also causing cell cycle arrest and apoptosis;the NC group exhibited the opposite effects.CONCLUSION This study demonstrated that SPARC could function as a tumor suppressor and might be silenced by promoter hypermethylation.Furthermore,in GC cells,SPARC inhibited migration,invasion,and proliferation,caused cell cycle arrest at the G0/G1 phase,and promoted apoptosis.

Diagnostic and prognostic value of secreted protein acidic and rich in cysteine in the diffuse large B-cell lymphoma

BACKGROUND Secreted protein acidic and rich in cysteine(SPARC)is an extracellular matrixassociated protein.Studies have revealed that SPARC is involved in the cell interaction and function including proliferation,differentiation,and apoptosis.However,the role of SPARC in cancer is controversial,as it was reported as the promoter or suppressor in different cancers.Further,the role of SPARC in lymphoma is unclear.AIM To identify the expression and significance of SPARC in lymphoma,especially in diffuse large B-cell lymphoma(DLBCL).METHODS The expression analysis of SPARC in different cancers was evaluated with Oncomine.The Brune,Eckerle,Piccaluga,Basso,Compagno,Alizadeh,and Rosenwald datasets were included to evaluate the mRNA expression of SPARC in lymphoma.The Cancer Genome Atlas(TCGA)-DLBCL was used to analyze the diagnostic value of SPARC in DLBCL.The Compagno and Brune DLBCL datasets were used for validation.Then,the diagnostic value was evaluated with the receiver operating characteristic(ROC)curve.The Kaplan-Meier plot was conducted with TCGA-DLBCL,and the ROC analysis was performed based on the survival time.Further,the overall survival analysis based on the level of SPARC expression was performed with the GSE4475 and E-TABM-346.The Gene Set Enrichment Analyses(GSEA)was performed to make the underlying mechanism-regulatory networks.RESULTS The pan-cancer analysis of SPARC showed that SPARC was highly expressed in the brain and central nervous system,breast,colon,esophagus,stomach,head and neck,pancreas,and sarcoma,especially in lymphoma.The overexpression of SPARC in lymphoma,especially DLBCL,was confirmed in several datasets.The ROC analysis revealed that SPARC was a valuable diagnostic biomarker.More importantly,compared with DLBCL patients with low SPARC expression,those with higher SPARC expression represented a higher overall survival rate.The ROC analysis showed that SPARC was a favorable prognostic biomarker for DLBCL.Results of the GSEA confirmed that the high expression of SPARC was closely associated with focal adhesion,extracellular matrix receptor interaction,and leukocyte transendothelial migration,which suggested that SPARC may be involved in the regulation of epithelial-mesenchymal transition,KRAS,and myogenesis in DLBCL.CONCLUSION SPARC was highly expressed in DLBCL,and the overexpression of SPARC showed sound diagnostic value.More interestingly,the overexpression of SPARC might be a favorable prognostic biomarker for DLBCL,suggesting that SPARC might be an inducible factor in the development of DLBCL,and inducible SPARC was negative in some oncogenic pathways.All the evidence suggested that inducible SPARC might be a good diagnostic and prognostic biomarker for DLBCL.

血清SPARC及SERPIND1与鼻咽癌患者放疗敏感性及预后的相关性

目的研究鼻咽癌(NPC)患者血清富含半胱氨酸的酸性分泌蛋白(SPARC)、纤维蛋白活化因子抑制蛋白(SERPIND1)表达与放疗敏感性及预后的关系。方法收集2017年1月—2019年1月南京大学医学院附属盐城第一医院肿瘤放疗科诊治NPC患者98例为NPC组,选取同期体检的健康人群60例为健康对照组。酶联免疫吸附试验检测血清SPARC、SERPIND1水平。根据NPC患者放疗反应性将NPC患者分为放疗敏感亚组(n=68)和放疗抵抗亚组(n=30)。比较不同临床病理特征、放疗反应的NPC患者血清SPARC、SERPIND1水平差异。绘制Kaplan-Meier曲线,Log-Rank检验比较不同SPARC、SERPIND1表达患者生存预后的差异。采用Cox回归分析NPC预后的影响因素。结果放疗前NPC组患者血清SPARC、SERPIND1水平高于健康对照组(t=37.535、48.522,P均<0.001)。放疗前放疗抵抗亚组NPC患者血清SPARC、SERPIND1水平明显高于放疗敏感亚组(t/P=14.034/<0.001、7.772/<0.001),放疗后2亚组血清SPARC、SERPIND1水平均降低,且放疗敏感亚组低于放疗抵抗亚组(t/P=22.974/<0.001、18.137/<0.001)。肿瘤TNM分期Ⅲ~Ⅳ期、有淋巴结转移NPC患者放疗前血清SPARC、SERPIND1水平高于TNM分期Ⅰ~Ⅱ期、无淋巴结转移者(t/P=16.539/<0.001、16.799/<0.001、15.756/<0.001、15.015/<0.001)。血清SPARC高表达和低表达患者3年总生存率分别为50.00%(24/48)、92.00%(46/50)。血清SERPIND1高表达和低表达患者3年总生存率分别为53.19%(25/47),88.24%(45/51),血清SPARC、SERPIND1高表达NPC患者3年累积生存率明显低于血清SPARC、SERPIND1低表达患者(Log-rankχ^(2)=21.500、14.790,P均<0.001)。TNM分期Ⅲ~Ⅳ期、淋巴结转移、SPARC高表达、SERPIND1高表达是影响NPC预后的独立危险因素[HR(95%CI)=1.608(1.225~2.112)、1.917(1.319~2.799)、1.839(1.228~2.753)、1.738(1.246~2.426)]。结论NPC患者血清SPARC、SERPIND1水平上调,与NPC患者不良临床病理特征及放疗敏感性有关,是评估NPC患者预后的血清肿瘤标志物。

Chronic spinal cord compression associated with intervertebral disc degeneration in SPARC-null mice

Chronic spinal cord compression(CSCC)is induced by disc herniation and other reasons,leading to movement and sensation dysfunction,with a serious impact on quality of life.Spontaneous disc herniation rarely occurs in rodents,and therefore establishing a chronic spinal cord compression(CSCC)animal model is of crucial importance to explore the pathogenesis and treatment of CSCC.The absence of secreted protein,acidic,and rich in cysteine(SPARC)leads to spontaneous intervertebral disc degeneration in mice,which resembles human disc degeneration.In this study,we evaluated whether SPARC-null mice may serve as an animal model for CSCC.We performed rod rotation test,pain threshold test,gait analysis,and Basso Mouse Scale score.Our results showed that the motor function of SPARC-null mice was weakened,and magnetic resonance images revealed compression at different spinal cord levels,particularly in the lumbar segments.Immunofluorescence staining and western blot assay showed that the absence of SPARC induced apoptosis of neurons and oligodendrocytes,activation of microglia/macrophages with M1/M2 phenotype and astrocytes with A1/A2 phenotype;it also activated the expression of the NOD-like receptor protein 3 inflammasome and inhibited brain-derived neurotrophic factor/tyrosine kinase B signaling pathway.Notably,these findings are characteristics of CSCC.Therefore,we propose that SPARC-null mice may be an animal model for studying CSCC caused by disc herniation.

Secreted protein acidic and rich in cysteine(SPARC)induces epithelial-mesenchymal transition,enhancing migration and invasion,and is associated with high Gleason score in prostate cancer

Secreted protein acidic and rich in cysteine(SPARC)is a matricellular protein highly expressed in bone tissue that acts as achemoattractant factor promoting the arrival of prostate cancer(PCa)cells to the bone marrow.However,the contribution of SPARCduring the early stages of tumor progression remains unclear.In this study,we show that SPARC is highly expressed in PCa tissueswith a higher Gleason score.Through stable knockdown and overexpression of SPARC in PC3 and LNCaP cells,respectively,here wedem on strate that en doge nous SPARC induces the epithelial-mesenchymal tran sition(EMT),decreasing E-cadheri n and cytokeratin18 and increasing N-cadheri n and vime ntin.Moreover,SPARC in duces the expression of EMT regulatory tran scription factors Snailfamily transcriptional repressor 1(Snail),Snail family transcriptional repressor 2(Slug),and zinc finger E-box binding homeobox 1(Zeb1).In addition,SPARC knockdown in PC3 cells decreases migration and invasion in vitro,without modifying cell proliferation.Our results indicate that SPARC might facilitate tumor progression by modifying the cellular phenotype in cancer cells.

Change of SPARC expression after chemotherapy in gastric cancer

Objective： The expression of tumor biomarkers may change after chemotherapy. However, whether secreted protein acidic and rich in cysteine （SPARC） expression changes after chemotherapy in gastric cancer （GC） is unclear, qqais study investigated the influence of chemotherapy on SPARC expression in GC. Methods： Immunohistochemistry was used to analyze SPARC expression in 132 GC cases （including 54 cases with preoperative chemotherapy and 78 cases without preoperative chemotherapy）. SPARC expression of postoperative specimens with and without preoperative chemotherapy was assessed to analyze the influence of chemotherapy on SPARC expression. Results： SPARC was highly expressed in GC compared with the desmoplastic stroma surrounding tumor cells and noncancerous tissues. High SPAKC expression was correlated with invasion depth, lymph node, and TNM stage. After chemotherapy, a lower proportion of high SPARC expression was observed in patients with preoperative chemotherapy than in the controls. For 54 patients with preoperative chemotherapy; gross type, histology, depth of invasion, lymph node, TNM stage, and SPARC expression were related to overall survival. Further multivariate analysis showed that lymph node, histology, and SPARC expression after chemotherapy were independent prognostic factors. Conclusiou： SPARC expression may change after chemotherapy in GC. SPARC expression should be reassessed for patients with GC after chemotherapy.

微小核糖核酸-451a在人参养荣汤治疗鼻咽癌放射性黏膜损伤中的机制研究

目的:通过检测微小核糖核酸-451a(miR-451a)和富含半胱氨酸的分泌性酸性蛋白(SPARC)mRNA的表达,推断人参养荣汤治疗鼻咽癌(NPC)放射性黏膜损伤的疗效及作用机制。方法:选择2022年3月—2023年5月收治的鼻咽癌放射性口腔黏膜损伤患者30例作为观察组,选择同期健康者30例作为对照组。采用辨证论治拟人参养荣汤加减治疗,比较观察组治疗前后患者中医症候积分量表和口干程度、口咽疼痛程度、黏膜损伤程度。检测治疗前后患者血清miR-451a和SPARC mRNA表达水平。结果:人参养荣汤可以有效降低患者主症和次症严重程度、Ⅲ级和Ⅳ级口腔黏膜损伤程度、口咽疼痛程度以及口干程度,使患者血清中miR-451a表达下降,促进SPARC mRNA蛋白翻译增强(P<0.05)。治疗前后,miR-451a与中医症候积分均呈正相关(P<0.05)。结论:人参养荣汤对鼻咽癌放射性黏膜损伤具有一定的临床疗效,可降低miR-451a表达水平,升高SPARC mRNA表达水平;miR-451a抑制了SPARC mRNA的翻译,可为将来的中西医结合治疗提供理论依据。

食管鳞癌组织中SPARC蛋白表达的临床意义

目的:探讨基质蛋白SPARC在食管鳞癌的增殖、侵润和转移中的作用。方法:应用免疫组化技术研究SPARC在食管鳞癌组织和其相邻的正常粘膜组织的表达差异,同时对蛋白表达进行定位。结果:36例食管鳞癌手术标本中30例SPARC蛋白表达阳性,正常食管上皮组织表达阴性(P<0.01)。SPARC蛋白在不同分化程度的食管鳞癌组织中的表达阳性率基本相同(P>0.05)。有淋巴结转移的食管鳞癌组织与无淋巴结转移癌组织的表达间有显著差异(P<0.05)。4例癌组织细胞核有表达,其余均为细胞浆表达。结论:SPARC和食管癌的发生与发展密切相关。食管癌出现转移时SPARC蛋白表达升高。

KLF4和SPARC在非小细胞肺癌中的表达及其相关性研究

背景与目的已有研究证实KLF4基因(Krüppel-like factor4)和富含半胱氨酸的酸性分泌蛋白(se-creted protein acidic and rich in cysteine,SPARC)与肿瘤的发生发展密切相关。本研究旨在检测KLF4和SPARC蛋白在非小细胞肺癌(non-small cell lung cancer,NSCLC)中的表达,并结合临床病理特征来探讨KLF4和SPARC的临床意义及相关性。方法应用免疫组织化学方法检测89例NSCLC组织及正常肺组织中KLF4和SPARC的表达。结果 KLF4在癌旁正常肺组织阳性表达率为88.8%,NSCLC组织为42.7%(P<0.05);有、无淋巴结转移者的KLF4阳性表达率分别为31.3%和56.1%(P<0.05);KLF4的表达与肿瘤临床分期有关(P<0.05),随着临床分期等级的增加,KLF4表达呈现递减趋势。SPARC在NSCLC组织的阳性表达率为70.8%,癌旁正常肺组织为7.9%(P<0.05);低、高分化癌的SPARC阳性表达率无统计学差异(P>0.05);有、无淋巴结转移者的SPARC阳性表达率分别为81.3%和58.5%(P<0.05);其表达与肿瘤的临床分期相关(P<0.05)。KLF4和SPARC的表达均与患者的性别、年龄和肿瘤大小无关(P>0.05)。SPARC和KLF4在NSCLC中的表达呈负相关(r=-0.245,P<0.05)。结论 KLF4低表达及SPARC的过表达与NSCLC的发生及其生物学行为密切相关,可能作为NSCLC诊断及分期预后的指标。

SPARC基因在角膜碱烧伤中的表达

目的 动态检测酸性富含胱氨酸分泌型蛋白 (SPA RC)在角膜碱烧伤中的表达 ,为探讨 SPA RC基因在角膜创伤中的作用提供依据。方法 首先建立角膜碱烧伤模型 ,并设角膜物理损伤组为对照组 ,在不同时间段提取各组角膜上皮细胞总RN A。用基因引物进行逆转录 -聚合酶链反应 (RT - PCR )扩增 ,半定量 SPA RC m RN A的表达水平。然后对 PCR扩增结果用限制性内切酶酶切验证。在取角膜上皮之前 ,对受试动物进行裂隙灯检查 ,以判断角膜碱烧伤程度与基因表达的关系。结果 (1)正常角膜上皮细胞可见 SPA RC基因的低表达 ;(2 ) SPA RC在角膜碱烧伤及物理损伤后均见较高水平表达 ,且与正常细胞表达相比较有显著的统计学差异 (P<0 .0 5) ;角膜创伤越严重 ,基因表达水平越高 ;(3 )所检测基因表达结果与显微镜观察角膜水肿、混浊、角膜新生血管等损伤结果呈同步趋势。结论 SPARC在角膜碱烧伤和创伤过程中具有高水平表达。是角膜创伤修复过程中的重要因素。

肝癌细胞中SPARC表达及其与糖酵解作用的相关性

目的探究肝细胞癌中分泌性富含半胱氨酸的酸性蛋白(secreted protien acidic and rich in cysteine,SPARC)表达及其与糖酵解作用的相关调节机制。方法选取肝癌细胞HepG2、Hep3B、Huh7,分别稳定转染SPARC质粒和SPARC siRNA,应用比色法检测2种转染的细胞中糖酵解关键酶己糖激酶(HK)和乳酸脱氢酶-A(LDHA)的活性变化。结果转染SPARC质粒的3种肝癌细胞中HK-Ⅱ、LDHA的活性较对照组明显下降,3种细胞中HK-Ⅱ相对吸光度分别降低至(57.45±5.05)%,(56.1±5.70)%,(49.73±7.06)%;LDHA相对吸光度分别降低至(50.53±8.07)%,(54.38±2.08)%,(42.34±3.44)%;差异均有统计学意义(P<0.05);反之,siRNA抑制SPARC表达的肝癌细胞中,HK-Ⅱ、LDHA活性较对照组明显上调,3种细胞中HK-Ⅱ相对吸光度分别上调至(174.20±8.41)%,(166.69±9.71)%,(152.84±3.39)%;LDHA的相对吸光度分别上调至(176.65±6.85)%;(163.24±6.44)%;(151.25±6.75)%,差异具有统计学意义(P<0.05)。结论肝细胞癌中,SPARC通过负性调控糖酵解作用的关键酶抑制糖酵解。

SPARC在db/db小鼠肾脏组织中高表达

目的检测db/db鼠肾脏组织中的富含半胱氨酸的酸性分泌蛋白(SPARC)的表达情况。方法 RT-PCR、Western blot及免疫荧光方法检测db/db鼠肾脏组织中的SPARC mRNA及蛋白的表达。结果 SPARC在db/db鼠肾脏组织中呈现高表达。结论 db/db鼠肾脏组织中的SPARC呈现高表达(P<0.05),可能与糖尿病肾病的发生与发展有关。

ob/ob鼠骨骼肌组织中SPARC的表达及临床意义

目的观察富含半胱氨酸的酸性分泌蛋白(secreted protein acidic rich in cysteine,SPARC)在具有肥胖及糖尿病表型的ob/ob鼠骨骼肌组织中的表达情况。方法选择10周龄的ob/ob小鼠(C57BL/6J-Lepob/J)与其同窝野生对照型各6只,取其后肢骨骼肌组织,采用RT-PCR方法检测骨骼肌组织中SPARC基因的表达水平,Western blot方法测定SPARC蛋白的表达水平,并用免疫荧光染色方法对骨骼肌组织进行染色观察。结果 SPARC在ob/ob鼠骨骼肌组织中呈现明显高表达。结论 SPARC可能参与了肥胖及糖尿病的发生。

SPARC在子宫颈鳞癌中的表达及其临床意义

目的:探讨富含半胱氨酸的酸性蛋白(Secreted protein acidic and rich in cysteine,SPARC)与子宫颈鳞状细胞癌(Squamous cervical carcinoma,SCC)的发展及浸润的关系。方法:采用免疫组化SP法检测18例正常子宫颈上皮(Normal cervical epithelium,NCE)、41例子宫颈上皮内瘤变(Cervical intraepithelial neoplasm,CIN)及72例组织中SPARC的表达,并分别检测CD34的表达。结果:从NCE到CIN到SCC组,SPARC的表达水平显著升高。在CIN组SPARC的表达随病变程度加重而升高;而SCC组中其与国际妇产科联盟(FIGO)分期、盆腔淋巴转移、浸润深度及脉管浸润有关,与组织学分级及年龄无关。从NCE到CIN到SCC组,CD34表达的微血管密度(Microvessel density,MVD)值显著升高,且与SPARC有相关性。结论:SPARC可能在SCC的发展及转移过程中其重要作用,可能成为判断宫颈病变生物学行为的一个重要指标。

SPARCL1基因在肿瘤发生中的作用

SPARCL1作为SPARC家族的成员之一,在生物生长发育及维持生理功能中起着重要作用。SPARCL1基因表达异常与消化系统肿瘤、泌尿系统肿瘤、非小细胞肺癌、卵巢癌、子宫肌瘤、乳腺癌及神经胶质瘤的发生、发展相关,并参与调节黏着斑等信号通路。深入研究SPARCL1基因在不同组织和系统肿瘤中的表达变化及其可能的下调机制和信号通路,可为研究肿瘤的发生机制、探寻新的肿瘤标志物和分子靶点提供重要的理论依据。

喉鳞癌组织中SPARC基因的差异表达

目的探讨富含半胱氨酸的酸性蛋白(SPARC)在喉鳞癌的增殖、侵润和转移中的作用及指导意义。方法用半定量逆转录-聚合酶链反应(RT-PCR)分析SPARC在不同的喉鳞癌组织和其相邻的正常粘膜组织的差异表达量。利用免疫组化技术研究SPARC在喉鳞癌组织和其相邻的正常粘膜组织的表达差异,同时对蛋白表达进行定位。结果RT-PCR分析SPARC在20对配对标本中的表达,在其中16对喉鳞癌组织中的表达明显高于其相应的正常粘膜组织,在4对中差异表达不明显,R=80.0%(有差异的例数/总例数)。免疫组化技术分析了30对配对喉鳞癌手术标本的石蜡切片(肿瘤组织和正常粘膜组织),其中25对SPARC蛋白在癌巢细胞中的表达高于相邻的正常粘膜组织,5例在癌巢细胞中和相邻的正常粘膜组织内表达不明显,R=83.3%。同时对SPARC蛋白在不同分化程度的喉癌组织中的表达进行分析,发现SPARC在中低分化喉癌中的表达与高分化喉癌无显著差异(P>0.05)。而在有淋巴结转移的喉癌的表达比无淋巴结转移的高(P=0.036)。细胞核和细胞浆均有表达。结论通过mRNA和蛋白水平分析得出,SPARC和喉鳞癌的发生密切相关,喉鳞癌淋巴结转移时SPARC表达升高。

乳腺浸润性导管癌组织中SPARC蛋白表达研究

目的探讨富含半胱氨酸的酸性分泌蛋白(SPARC)在乳腺浸润性导管癌组织中的表达及意义。方法以乳腺浸润性导管癌手术切除标本作为研究对象,运用免疫组化EnVision二步法检测癌组织(乳腺浸润性导管癌组,n=61)中SPARC的表达,以远离肿瘤的乳腺组织作为对照(对照组,n=32)。对与SPARC表达可能相关的因素进行分析。结果对照组上皮细胞中SPARC阳性表达率为31.3%,间质细胞未见SPARC表达(0%)。SPARC在乳腺浸润性导管癌组的癌细胞和间质细胞中均有表达,在间质细胞的阳性表达率为70.5%,与相应对照组比较差异有统计学意义(P<0.001)。伴淋巴结转移乳腺浸润性导管癌肿瘤细胞中SPARC阳性表达率显著高于不伴淋巴结转移者(46.7%vs 22.6%),两者比较差异具有统计学意义(P<0.05);乳腺浸润性导管癌中SPARC表达与患者年龄和肿瘤大小、组织学分级、TNM分期等均无明显相关性(P>0.05)。伴有癌转移淋巴结的SPARC阳性表达与原发肿瘤的临床分期有关(P<0.05)。结论SPARC在乳腺浸润性导管癌肿瘤间质细胞中的表达显著增高,提示SPARC可能通过间质细胞对肿瘤细胞的调控参与乳腺癌的发生;同时肿瘤细胞SPARC表达与乳腺癌转移相关。确切机制尚待进一步深入研究。

沉默SPARC基因抑制高氟介导的甲状腺细胞凋亡

目的研究富含半胱氨酸的酸性分泌蛋白(SPARC)对高氟介导的甲状腺细胞凋亡的作用及可能机制。方法培养人甲状腺细胞Nthy-ori 3-1,给予不同浓度的NaF(0.1、1、10 mmol/L)处理24 h,通过实时定量PCR和蛋白印迹法评价SPARC的表达,确定后续实验NaF作用浓度。另将细胞分组进行实验:对照组、NaF组(1 mmol/L孵育24 h)、si-SPARC组(转染SPARC siRNA 48 h用NaF处理)和si-NC组(转染Negative control siRNA 48 h用NaF处理)。CCK-8法和乳酸脱氢酶(LDH)试剂盒检测细胞毒性;细胞凋亡试剂盒检测细胞凋亡率,蛋白印迹法检测活化caspase3(c-caspase3)和IGF-1R的蛋白表达。此外,将siSPARC和siIGF-1R共同转染至甲状腺细胞,通过评价细胞凋亡进一步探讨SPARC的作用机制。结果随着NaF的浓度增大,SPARC mRNA和蛋白表达均逐渐升高(P<0.05)。si-SPARC组细胞活性较si-NC组增高[(84.02±9.51)%vs.(58.31±6.86)%,P<0.05],且LDH释放率减少[(134.25±18.98)%vs.(195.18±23.50)%,P<0.05]。si-SPARC组较si-NC组细胞凋亡率减少[(124.67±19.44)%vs.(175.24±16.46)%,P<0.05]。此外,si-SPARC组(1.95±0.24 vs. 0.93±0.08,P<0.05)IGF-1R蛋白表达上调,抑制IGF-1R逆转SPARC对细胞凋亡的作用。结论沉默SPARC基因降低高氟介导的细胞毒性、抑制细胞凋亡,其机制可能是通过负调控IGF-1R实现的。

病理性瘢痕组织中SPARC的表达变化及意义

目的观察富含半胱氨酸的酸性分泌糖蛋白(SPARC)在瘢痕疙瘩和增生性瘢痕中的表达变化及其意义。方法病理性瘢痕患者52例,其中瘢痕疙瘩(瘢痕组)和增生性瘢痕组织(增生组)各26例,另取正常皮肤组织5例为对照(对照组)。采用免疫组化SP法检测三组SPARC。将三组组织中的成纤维细胞传代培养(4～6代),采用Western blot法检测其SPARC。结果瘢痕组、增生组中SPARC表达较弱,虽比对照组高,但P>0.05;在早期增生性瘢痕(3～6个月)中的表达与晚期(9～12个月)近似(P>0.05)。瘢痕组、增生组成纤维细胞中SPARC表达均高于对照组(P均<0.05)。结论病理性瘢痕组织中的SPARC均呈低表达,其成纤维细胞中的SPARC呈高表达,这可能与病理性瘢痕的发生有关。

SPARC在肝癌细胞中负性调控糖酵解作用的研究

目的:探究肝癌细胞中的分泌性富含半胱氨酸的酸性蛋白(secreted protein acidic and rich in cysteine,SPARC)的表达与糖酵解作用的关系。方法:用SPARC质粒和SPARC siRNA分别转染人肝癌细胞株HepG2,转染后采用比色法检测细胞的葡萄糖摄取量以及乳酸生成量的变化。结果:转染SPARC质粒后的HepG2细胞的葡萄糖摄取量和乳酸生成量较对照组下降(P<0.05);转染SPARC siRNA后的HepG2细胞的葡萄糖摄取量和乳酸生成量较对照组增加(P<0.05)。结论:在肝癌细胞中,SPARC对糖酵解过程具有负性调控作用。