MicroRNA-298 determines the radio-resistance of colorectal cancer cells by directly targeting human dual-specificity tyrosine(Y)-regulated kinase 1A

BACKGROUND Radiotherapy stands as a promising therapeutic modality for colorectal cancer(CRC);yet,the formidable challenge posed by radio-resistance significantly undermines its efficacy in achieving CRC remission.AIM To elucidate the role played by microRNA-298(miR-298)in CRC radio-resistance.METHODS To establish a radio-resistant CRC cell line,HT-29 cells underwent exposure to 5 gray ionizing radiation that was followed by a 7-d recovery period.The quantification of miR-298 levels within CRC cells was conducted through quantitative RT-PCR,and protein expression determination was realized through Western blotting.Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and proliferation by clonogenic assay.Radio-induced apoptosis was discerned through flow cytometry analysis.RESULTS We observed a marked upregulation of miR-298 in radio-resistant CRC cells.MiR-298 emerged as a key determinant of cell survival following radiation exposure,as its overexpression led to a notable reduction in radiation-induced apoptosis.Intriguingly,miR-298 expression exhibited a strong correlation with CRC cell viability.Further investigation unveiled human dual-specificity tyrosine(Y)-regulated kinase 1A(DYRK1A)as miR-298’s direct target.CONCLUSION Taken together,our findings underline the role played by miR-298 in bolstering radio-resistance in CRC cells by means of DYRK1A downregulation,thereby positioning miR-298 as a promising candidate for mitigating radioresistance in CRC.

Role of microRNA-21 in uveal melanoma cell invasion and metastasis by regulating p53 and its downstream protein

AIM： To reveal the insight mechanism of liver metastasis in uveal melanoma, we investigated cell functions of microRNA-21 in three different uveal melanoma cell lines and analyze the relationship of target gene p53 and its downstream targets which been found significant expression in our previous study.METHODS： Quantitative real-time polymerase chain reaction （qRT-PCR） was used to detect microRNA-21 expression in normal uveal tissue and uveal melanoma cell lines. Lenti-virus expression system was used to construct OCM-1, MuM-2B and M619 cell line with stable overexpression and inhibition of microRNA-21. In vitro cell function tests such as cell proliferation, cell apoptosis, cell circle and abilities of migration and invasion were examined by MTT, BrdU assay, flow cytometry, transwell assay and Matrigel invasion assay respectively. The target gene was predicted by bioinformatics and confirmed by using a dual luciferase reporter assay. The expression of p53 and its suspected downstream targets LIM and SH3 protein 1 （LASP1） and Glutathione S Transferase pi （GST-Pi） were determined by qRT-PCR in mRNA level and western blotting analysis in protein level. Finally, the effect of microRNA-21 in a xenograft tumor model was assessed in four-week-old BALB/c nude mice. RESULTS： Compared to normal uveal melanoma, expressions of microRNA-21 were significantly higher in uveal melanoma cell lines. Overexpression of microRNA-21 promoted proliferation, migration, and invasion of OCM-1, M619 and MuM-2B cells, while inhibition of microRNA-21 reveal opposite effects. Wild type p53 was identified as a target gene of microRNA-21-3p, and proved by dual luciferase reporter assay. Up-regulated microRNA-21 inhibited the expression of wild type p53 gene, and the increased expression of LASP1 in mRNA level and protein level, while down-regulated microRNA-21 presented opposite way. However, GST-pi showed the potential pattern as expected, but relative mRNA level showed no statistically significant difference in OCM-1 cells. Furthermore, the mRNA expression of GST-pi was decreased in microRNA-21 overexpressing MuM-2B, and increased in M619 cells with inhibition of microRNA-21. In vivo, inhibition of microRNA-21 reduced tumor growth with statistically significant difference.CONCLUSION： These findings provide novel insight into molecular etiology of microRNA-21 in uveal melanoma cell lines, and suggest that microRNA-21 might be a potential candidate for the diagnosis and prognostic factor of human uveal melanoma in future.

Down-expression of tumor protein p53-induced nuclear protein 1 in human gastric cancer

AIM： Overexpression of tumor protein p53-induced nudear protein 1 （TP53INP1） induces G1 cell cycle arrest and increases p53-mediated apoptosis. To clarify the clinical importance of TP53INP1, we analyzed TP53INP1 and p53 expression in gastric cancer, METHODS： TP53INP1 and p53 expression were examined using immunohistochemistry in 142 cases of gastric cancer. The apoptosis of gastric cancer cells was analyzed using the TUNEL method. The relationship between the expression of TP53INP1 and clinicopathological factors was statistically analyzed. RESULTS： TP53INP1 was expressed in 98% （139/142 cases） of non-cancerous gastric tissues and was downexpressed in 64% （91/142 cases） of gastric cancer lesions from the same patients. TP53INP1 expression was significantly decreased （43.9%） in poorly differentiated adenocarcinoma compared with well or moderately differentiated adenocarcinoma （81.6%）. Cancers invading the submucosa or deeper showed lower positively （59.1%） compared with mucosal cancers （85.2%）. Decrease or loss of TP53INP1 expression was significantly correlated with lymphatic invasion （54.3% vs 82.0% without lymphatic invasion） and node-positive patients （31.3% vs 68.3% in node-negative patients）. P53 was expressed in 68 （47.9%） patients of gastric cancer, whereas it was absent in normal gastric tissues. A significant association was also observed between TP53INP1 status and the level of apoptosis in tumor cells： the apoptotic index in TP53INP1-positive tissues was significantly higher than that in TP53INP41-negative portions. Finally, when survival data were analyzed, loss of TP53INP1 expression had a significant effect in predicting a poor prognosis （P= 0.0006）.CONCLUSION： TPS3INP1-positive rate decreases with the progression of gastric cancer. TPS3INP1 protein negativity is significantly associated with aggressive pathological phenotypes of gastric cancer. TPS3INP1 is related to the apoptosis of gastric cancer cells. The decreased expression of the TPS3INP1 protein may reflect the malignant grade of gastric cancer and is regarded as an adverse prognostic factor.

Roles of syndecan-1, bcl6 and p53 in diagnosis and prognostication of immunoproliferative small intestinal disease

AIM： To evaluate roles of syndecan-1, bcl6 and p53 in diagnosis and prognostication of immunoproliferative small intestinal disease （IPSID） and to study profiles of kappa （κ） and lambda （λ） light chains and IgA heavy chain. METHODS： The study consisted of 11 cases of IPSID and similar number of controls which included 11 of normal intestinal mucosa and 11 of high grade B cell lymphoma of ileum. The parameters analyzed included clinical profiles, biochemical and other laboratory investigations, radiologic and histological findings including immunohistochemistry. RESULTS： All IPSID cases had demonstrable serum IgA heavy chain and heavy mucosal plasma cell infiltration. According to Galian＇s histological staging, there were 4 patients with stage A and 7 with stage B. κ and ;λ light chains were over-expressed in 7 patients; 1 stage A patient had H pylori-positive active gastritis and eradication of H pylori led to disease remission. Stage A biopsies had higher expression for syndecan-1, while stage B had higher expression for bcl6 and p53. Syndecan-1,κ and λ light chains and IgA heavy chain showed inverse relationship with bcl6 and p53. All patients were treated with doxycycline. CHOP regime was added in 5 patients who developed frank lymphoma. Three died of the disease due to extensive organ infiltration. CONCLUSION： Certain immunomarkers like syndecan-1,κ and λ light chains and IgA heavy chain could be of much help in identifying early stage IPSID. Stage B IPSID showed higher expression for bcl6 and p53 than stage A IPSID. bcl6 and p53 expressions correlated with a more advanced disease stage and aggressive tumour behavior.

THE OVEREXPRESSION AND SIGNIFICANCE OF CYCLIN D1 AND P53 IN CERVICAL SQUAMOUS CELL CARCINOMAS

Objective To investigate the significance of overexpresson of cyclin D1 and P53 protein in cervical squamous cell carcinomas.Methods Fifty cases of invasive cervical squamous cell carcinomas and 10 cases of normal cervical squamous epithelia were investigated with immunihistochemical technique. Results The overexpression of cyclin D1 and P53 in invasive cervical carcinomas was 70% and 50%, respectively. There was no overexpression of them in the control group. The overexpression of cyclin D1 in grade Ⅱ and Ⅲ was much higher than that in gradeⅠ(P<0.05). The overexpresson of cyclin D1 in stage Ⅲ of cervical carcinoma was significantly higher than that in stage Ⅱ (P<0.05). The overexpression of P53 in grade Ⅱ and grade Ⅲ of cervical carcinoma was remarkably higher than that in grade Ⅰ (P<0.05).Conclusion The action point of both cyclin D1 and P53 may be at G1/S transition. The overexpression of them was associated with development and progression of cervical carcinoma probably in different mechanisms and different pathways.

Expression of the chemoresistance-related proteins and p53 gene as a predictor of chemotherapy response and a prognostic factor in patients with ovarian cancer at the stages of II-IV

Objective To clarify the prognostic significance of histologic subtype and its correlation to expression of chemoresistance-related proteins （CRPs） in ovarian cancer. Methods A total of 107 stage II-IV ovarian cancers, where the proportion of serous, endometrioid, mucinous, and clear cell subtype was 62.6%, 15.9%, 14.0%, and 7.5%, respectively, were investigated for glutathione Stransferase-pi （GST-pi）, MDR （multidrug resistance）-l, and p53 expression using immunohistochemistry. Results GST-pi expression was detected in 62.6% of the tumors and was not related to histologic subtype of tumor. MDR-1 expression was observed in 52.3% of the tumors tested and was more frequently detected in serous adenocarcinomas than other histologic subtypes of tumor （P〈0.001）. P53 expression was found in 43.3% of serous, 35.3% of endometrioid, 40.0% of mucinous adenocarcinomas and 37.5% of clear cell adenocarcinomas. In univariate analysis, there are direct correlations between CRPs and overall survival. In multivariate analysis, GST-pi expression （P=0.0052）, MDR-1 expression （P=0.0058）, histologic subtype （P=0.0067）, FIGO stage （P=0.0089）, and residual tumor （P=0.0041） were found to be significant independent prognostic factors. Conclusion Histologic subtype proved to be the significant independent prognostic factor in addition to FlGO stage and residual tumor in stage II-IV ovarian cancer. GST-pi, MDR-1, and p53 expression pattern is closely related to histologic subtype of ovarian cancer, at the same time they are the significant predictors of survival.

EXPRESSIONS OF P_(53), PROLIFERATING CELL NUCLEAR ANITIGEN,BCL-2 PROTEIN AND THEIR SIGNIFICANCE IN SALIVARY ADENOID CYSTIC CARCINOMA

Objective To study the effects of P53, PCNA, Bc1-2 protein and their relationship in salivary adenoid cystic carclnoma(SACC). Methods These protelns were examlned by lmmunohistochemistry. Results overexpressions of Ps, and PCNA were revealed in ACC samples, they were higher than those in (polymorphous adenomas) PA, but expression of Bc1-2 protein was not different between ACC and PA. In 3 subtypes of ACC, expressions of 3 proteins were different. Conciusion Mutations of P53, Bc1-2 may be involed in the occurrence of SACC, expression of PCNA and mutation of P53 may coexist in the development of the SACC.

Oncoprotein expression and inhibition of apoptosis during colorectal tumorigenesis

AIMS To study bcl-2 and P53 protein expression and inhibition of apoptosis during colorectal tumorigenesis. METHODS Expression of bcl -2 and p53 in 45 colorectal ade- nomas and 61 colorectal carcinomas was detected by immunohis- tochemical staining. RESULTS The bcl-2 and P53 protein expression was uniformly negative in normal mucosa,whereas bcl-2 and p53 positive rates were significantly higher in adenoma and carcinoma than in nor- reals(P<0.01 ).The area with strong bcl-2 expression was of- ten the area with severely dysplasia.In colorectal adenoma,ex- pression of p53 increased with the increasing size and dysplasia, in adenomas≥20 mm being higher than adenomas<10 mm(77, 8% vs 35.0%,P<0.05).p53 was relevant to differentiation and Duke's staging.A significant inverse correlation was found between bcl-2 and p53 in immunostaining in the adenomas,but not in the carcinomas.Furthermore,carcinomas with a high per- centage of bcl-2 positive cells were significantly more likely to have low rates of apoptosis. CONCLUSIONS These results suggest that bcl-2 gene appears to be an early event in colorectal tumorigenesis that can inhibit apoptosis,p53 expression plays an important role in the develop- ment and malignant change of colorectal adenoma,bcl-2 and p53 may be used as a good marker relating to cell apoptosis.

Human umbilical cord mesenchymal stem cells attenuate diabetic nephropathy through the IGF1R-CHK2-p53 signalling axis in male rats with type 2 diabetes mellitus

diabetes mellitus(DM)is a disease syndrome characterized by chronic hyperglycaemia.A long-term high-glucose environment leads to reactive oxygen species(ROS)production and nuclear DNA damage.human umbilical cord mesenchymal stem cell(HUcMSC)infusion induces significant antidiabetic effects in type 2 diabetes mellitus(T2DM)rats.Insulin-like growth factor 1(IGF1)receptor(IGF1R)is important in promoting glucose metabolism in diabetes;however,the mechanism by which HUcMSC can treat diabetes through IGF1R and DNA damage repair remains unclear.In this study,a DM rat model was induced with high-fat diet feeding and streptozotocin(STZ)administration and rats were infused four times with HUcMSC.Blood glucose,interleukin-6(IL-6),IL-10,glomerular basement membrane,and renal function were examined.Proteins that interacted with IGF1R were determined through coimmunoprecipitation assays.The expression of IGF1R,phosphorylated checkpoint kinase 2(p-CHK2),and phosphorylated protein 53(p-p53)was examined using immunohistochemistry(IHC)and western blot analysis.Enzyme-linked immunosorbent assay(ELISA)was used to determine the serum levels of 8-hydroxydeoxyguanosine(8-OHdG).Flow cytometry experiments were used to detect the surface markers of HUcMSC.The identification of the morphology and phenotype of HUcMSC was performed by way of oil red“O”staining and Alizarin red staining.DM rats exhibited abnormal blood glucose and IL-6/10 levels and renal function changes in the glomerular basement membrane,increased the expression of IGF1 and IGF1R.IGF1R interacted with CHK2,and the expression of p-CHK2 was significantly decreased in IGF1R-knockdown cells.When cisplatin was used to induce DNA damage,the expression of p-CHK2 was higher than that in the IGF1R-knockdown group without cisplatin treatment.HUcMSC infusion ameliorated abnormalities and preserved kidney structure and function in DM rats.The expression of IGF1,IGF1R,p-CHK2,and p-p53,and the level of 8-OHdG in the DM group increased significantly compared with those in the control group,and decreased after HUcMSC treatment.Our results suggested that IGF1R could interact with CHK2 and mediate DNA damage.HUcMSC infusion protected against kidney injury in DM rats.The underlying mechanisms may include HUcMSC-mediated enhancement of diabetes treatment via the IGF1R-CHK2-p53 signalling pathway.

Inhibition of apoptosis by oncogenic hepatitis B virus X protein: Implications for the treatment of hepatocellular carcinoma

Hepatitis B virus X protein(HBx) plays an important role in the development of hepatocellular carcinoma(HCC). In addition, hepatoma upregulated protein(HURP) is a cellular oncogene that is upregulated in a majority of HCC cases. We highlight here recent findings demonstrating a link between HBx, HURP and anti-apoptosis effects observed in cisplatin-treated HCC cells. We observed that Hep3B cells overexpressing HBx display increased HURP mRNA and protein levels, and show resistance to cisplatin-induced apoptosis. Knockdown of HURP in HBx-expressing cells reverses this effect, and sensitizes cells to cisplatin. The anti-apoptotic effect of HBx requires activation of the p38/MAPK pathway as well as expression of SATB1, survivin and HURP. Furthermore, silencing of HURP using short-hairpin RNA promotes accumulation of p53 and reduces cell proliferation in SK-Hep-1 cells(p53^(+/–)), whereas these effects are not observed in p53-mutant Mahlavu cells. Similarly, HURP silencing does not affect the proliferation of H1299 lung carcinoma cells or Hep3 B HCC cells which lack p53. Silencing of HURP sensitizes SK-Hep-1 cells to cisplatin. While HURP overexpression promotes p53 ubiquitination and degradation by the proteasome, HURP silencing reverses these effects. Inoculation of SK-Hep-1 cancer cells in which HURP has been silenced produces smaller tumors than control in nude mice. Besides, gankyrin, a positive regulator of the E3 ubiquitin ligase MDM2, is upregulated following HURP expression, and silencing of gankyrin reduces HURP-mediated downregulation of p53. In addition, we observed a positive correlation between HURP and gankyrin protein levels in HCC patients(r^2 = 0.778; n = 9). These findings suggest a role for the viral protein HBx and the host protein HURP in preventing p53-mediated apoptosis during cancer progression and establishment of chemoresistance.

Adenosine monophosphate-activated protein kinase activation enhances embryonic neural stem cell apoptosis in a mouse model of amyotrophic lateral sclerosis

Alterations in embryonic neural stem cells play crucial roles in the pathogenesis of amyotrophic lateral sclerosis. We hypothesized that embryonic neural stem cells from SOD1G93A individuals might be more susceptible to oxidative injury, resulting in a propensity for neurodegeneration at later stages. In this study, embryonic neural stem cells obtained from human superoxide dis- mutase 1 mutant （SOD1G93A） and wild-type （SOD1wv） mouse models were exposed to H202. We assayed cell viability with mitochondrial succinic dehydrogenase colorimetric reagent, and measured cell apoptosis by flow cytometry. Moreover, we evaluated the expression of the adenos- ine monophosphate-activated protein kinase （AMPK） ct-subunit, paired box 3 （Pax3） protein, and p53 in western blot analyses. Compared with SOD1wr cells, SOD1~93A embryonic neural stem cells were more likely to undergo H202-induced apoptosis. Phosphorylation of AMPKct in SOD1G93A cells was higher than that in SOD1wr cells. Pax3 expression was inversely correlated with the phosphorylation levels of AMPKct. p53 protein levels were also correlated with AMPKct phosphorylation levels. Compound C, an inhibitor of AMPKa, attenuated the effects of H20~. These results suggest that embryonic neural stem cells from SOD1C93A mice are more susceptible to apoptosis in the presence of oxidative stress compared with those from wild-type controls, and the effects are mainly mediated by Pax3 and p53 in the AMPKa pathway.

PDRG1 at the interface between intermediary metabolism and oncogenesis

PDRG1 is a small oncogenic protein of 133 residues. In normal human tissues, the p53 and DNA damageregulated gene 1(PDRG1) gene exhibits maximal expression in the testis and minimal levels in the liver. Increased expression has been detected in several tumor cells and in response to genotoxic stress. High-throughput studies identified the PDRG1 protein in a variety of macromolecular complexes involved in processes that are altered in cancer cells. For example, this oncogene has been found as part of the RNA polymerase Ⅱ complex, the splicing machinery and nutrient sensing machinery, although its role in these complexes remains unclear. More recently, the PDRG1 protein was found as an interaction target for the catalytic subunits of methionine adenosyltransferases. These enzymes synthesize S-adenosylmethionine, the methyl donor for, among others, epigenetic methylations that occur on the DNA and histones. In fact, downregulation of S-adenosylmethionine synthesis is the first functional effect directly ascribed to PDRG1. The existence of global DNA hypomethylation, together with increased PDRG1 expression, in many tumor cells highlights the importance of this interaction as one of the putative underlying causes for cell transformation. Here, we will review the accumulated knowledge on this oncogene, emphasizing the numerous aspects that remain to be explored.

广西肝癌组织中P^（53）蛋白和乙肝病毒免疫学标志物的检测

用免疫组化法测定广西２９例人肝癌及其癌旁组织中的Ｐ５３蛋白、ＨＢｓＡｇ和ＨＢｘＡｇ。４４．８％肝癌病例为Ｐ５３蛋白阳性，其癌内及癌旁Ｐ５３蛋白的检出率分别为２７．６％和２８．６％。２１％的肝癌内及８５．７％的癌旁肝组织中可见到ＨＢｓＡｇ。３１％的癌内及７５％的非癌肝组织呈ＨＢｘＡｇ阳性。Ｐ５３蛋白阳性的１３例病例有１１例（８４．６％）可同时检测出ＨＢｓＡｇ和ＨＢｘＡｇ。结果显示：广西肝癌与Ｐ５３基因突变、乙型肝炎病毒（ＨＢＶ）感染关系密切。

PLK1和P53蛋白在卵巢上皮性癌中的表达及其意义

2目的检测POLO样蛋白激酶1（PLK1）和P53蛋白在卵巢上皮性癌中的表达，探讨其与患者预后的关系。方法采用免疫组织化学SP法检测20例正常卵巢组织、19例卵巢良性上皮性肿瘤组织和52例卵巢上皮性癌组织中PLK1和P53蛋白的表达情况，分析其与卵巢癌临床病理指标的关系及二者在卵巢癌组织中表达的相关性，单因素和多因素Logistic回归分析影响卵巢癌患者预后的危险因素，Kaplan-Meier法分析PLK1和P53表达与卵巢癌患者预后的关系。结果 PLK1和P53在卵巢上皮性癌组织中的表达分别为38.5%和67.3%，显著高于良性肿瘤和正常卵巢组织（P＜0.05）。在卵巢上皮性癌中，PLK1和P53异常高表达与临床分期和组织分化相关，临床分期越晚、组织分化越差的癌组织中PLK1和P53蛋白表达越高（P＜0.05）； PLK1蛋白的表达与P53蛋白的表达呈负相关（r＝-0.629，P＝0.000）。单因素Logistic回归分析显示PLK1、P53、临床分期、组织分化和淋巴结转移是影响卵巢癌患者预后的因素，多因素Logistic回归分析显示仅PLK1是影响卵巢癌患者预后的独立因素（OR＝2.288，P＝0.025，95% CI：0.105～50.050）。与其他患者相比，PLK1表达阳性同时P53表达阳性的卵巢癌患者，生存期最短（χ2＝17.246，P＝0.037）。结论 PLK1和P53共同参与了卵巢癌的发生发展，PLK1可作为判断卵巢癌患者预后的标志物。

Regulation of DNA double-strand break repair pathway choice:a new focus on 53BP1

Maintenance of cellular homeostasis and genome integrity is a critical responsibility of DNA double-strand break(DSB)signaling.P53-binding protein 1(53BP1)plays a critical role in coordinating the DSB repair pathway choice and promotes the non-homologous end-joining(NHEJ)-mediated DSB repair pathway that rejoins DSB ends.New insights have been gained into a basic molecular mechanism that is involved in 53BP1 recruitment to the DNA lesion and how 53BP1 then recruits the DNA break-responsive effectors that promote NHEJ-mediated DSB repair while inhibiting homologous recombination(HR)signaling.This review focuses on the up-and downstream pathways of 53BP1 and how 53BP1 promotes NHEJ-mediated DSB repair,which in turn promotes the sensitivity of poly(ADP-ribose)polymerase inhibitor(PARPi)in BRCA1-deficient cancers and consequently provides an avenue for improving cancer therapy strategies.

Chromosome 1p/19q status combined with expression of protein improves the diagnostic and prognostic evaluation of oligodendrogliomas

Background Our previous study confirmed that oligodendrogliomas had higher frequency of chromosome 1p/19q deletion. In order to improve the diagnostic criteria and to predict the prognosis of oligodendroglioma patients, the status of chromosome 1 p/19q deletion, the methylation of O6-methylguanine-DNA methyltransferase （MGMT）, and the expression of p53 protein were evaluated and investigated in relation to patients＇ outcomes.Methods Methylation of MGMT in 73 cases was analyzed by nested methylation-specific PCR （MSP）. The levels of MGMT and p53 protein were tested with immunohistochemistry. Pearson＇s chi-square test and Fisher＇s exact test were used. Multivariate and Kaplan-Meier analysis were performed to determine patients＇ outcomes.Results Both oligodendrogliomas and astrocytic gliomas exhibited frequent methylation of MGMT. However, the results of MSP did not completely correspond to that of the immunohistochemical staining for MGMT. The expression of p53 protein was more frequently observed in patients without a 1 p or 19q deletion in anaplastic oligodendrogliomas （=0.032,0.025）. In low-grade oligodendrogliomas, methylation of MGMT was more frequent in patients with 1 p/19q deletion than in patients with 1p/19q intact （P=0.038）. Patients with oligodendrogliomas with 1p/19q loss of heterozygosity and p53-negative showed a longer progression-free survival.Conclusion Detection of chromosome 1p/19q status combined with p53 protein immunohistochemistry might be beneficial to improve the pathological diagnosis and to determine the prognosis of patients with oligodendrogliomas.

Comprehensive Diagnostic Value of P53, p21WAF1 and Proliferating Cell Nuclear Antigen for Lung Cancer

The expression of P53, p21WAF1 and proliferating cell nuclear antigen （PCNA） was detected in 114 samples of lung cancer patients （with 89 cases benign lung tissue as control） and the diagnostic value of these markers was evaluated. The results show the following： （1） The positive expression rates of P53, p21WAF1 and PCNA in samples of lung cancer were 47.37%, 75.44% and 80.70%, respectively, which were significantly higher than that in the samples of benign lung diseases （ p 〈 0. 001 ）. The odds ratios were 39.15, 5.75, and 6.76, respectively. This indicates that the expression of P53, p21WAF1 and PCNA was helpful for the diagnosis of lung cancer. （2） For the diagnosis of lung cancer, the positive likelihood ratio of P53 was 21.08, which were significantly higher than that of p21WAF 1 （2.16）, PCNA （2.11） and of all the combined tests. This shows that P53 expression was the most valuable for diagnosis of lung cancer. （3） For the diagnosis of lung cancer, the negative likelihood ratio of P53/p21WAF 1/PCNA parallel test was 0.057 1, which was lower than that of other single and combined tests. This indicates that P53/p21WAF 1/PCNA parallel test has high diagnostic value for exclusion of lung cancer.

Nucleolus-localized Def-CAPN3 protein degradation pathway and its role in cell cycle control and ribosome biogenesis

The nucleolus,as the‘nucleus of the nucleus’,is a prominent subcellular organelle in a eukaryocyte.The nucleolus serves as the centre for ribosome biogenesis,as well as an important site for cell-cycle regulation,cellular senescence,and stress response.The protein composition of the nucleolus changes dynamically through protein turnover to meet the needs of cellular activities or stress responses.Recent studies have identified a nucleolus-localized protein degradation pathway in zebrafish and humans,namely the Def-CAPN3 pathway,which is essential to ribosome production and cell-cycle progression,by controlling the turnover of multiple substrates(e.g.,ribosomal small-subunit[SSU]processome component Mpp10,transcription factor p53,check-point proteins Chk1 and Wee1).This pathway relies on the Ca2þ-dependent cysteine proteinase CAPN3 and is independent of the ubiquitin-mediated proteasome pathway.CAPN3 is recruited by nucleolar protein Def from cytoplasm to nucleolus,where it proteolyzes its substrates which harbor a CAPN3 recognition-motif.Def depletion leads to the exclusion of CAPN3 and accumulation of p53,Wee1,Chk1,and Mpp10 in the nucleolus that result in cell-cycle arrest and rRNA processing abnormality.Here,we summarize the discovery of the Def-CAPN3 pathway and propose its biological role in cell-cycle control and ribosome biogenesis.

STUDY OF ECK GENE EXON-3 FROM HUMAN NORMAL TISSUE AND BREAST CANCER CELL LINE

Objective To establish a method cloning the exon 3 of eck gene from normal tissue and ZR 75 1 cell line (a human breast cancer cell line)and study whether these genes exist mutant. Methods Designed a pair of specific primers and amplified the exon 3 of eck gene fragment from the extracted genomic DNA derived from normal epithelial cells from skin tissue and ZR 75 1 cell line respectively by PCR technique. Transformed the E.coil. JM109 with recombinant plamids constructed by inserting the amplified fragments into medium vector pUCm T and sequenced these amplified fragments after primary screening of endonuclease restriction digestion and PCR amplification. Results ① Obtained the genomic DNA of human normal epithelial cells and ZR 75 1 cell line respectively. ② Obtained the amplified fragments of human exon 3 of eck gene through PCR technique. ③ Obtained the cloning vectors of exon 3 of eck gene of human normal epithelial cells and ZR 75 1 cell line respectively. ④ ZR 75 1 cell line exists mutation of nucleotides. Conclusion Successfully established the method of cloning the human exon 3 of eck gene and found some mutations in the detected samples. This study lays a foundation for further studying the function of eck gene in tumorgenesis.