Celecoxib enhances the response of tumor cells to cisplatin through upregulating PUMA in non–small cell lung cancer carrying wild-type p53

Celecoxib,a cyclooxygenase-2 inhibitor,can enhance the efficacy of chemotherapy;however,its effect seems inconsistent.In this study,we investigated whether celecoxib would increase the antiproliferative effects of cisplatin in human lung cancer cells.Our data demonstrated the synergistic effects of celecoxib with cisplatin in wild-type p53 cells and their antagonistic effects inmutated or deleted p53 cells.Combination indices of 0.82 to 0.93 reflected a synergistic effect between celecoxib and cisplatin in lung cancer cells with wild-type p53.Combination indices of 1.63 to 3.00 reflected antagonism between celecoxib and cisplatin in lung cancer cells with mutated or deleted p53.Compared with that in cells with mutated or deleted p53,apoptosis significantly increased with the addition of celecoxib and cisplatin in wild-type p53 cells(P<0.05).Moreover,the results in vivo were similar to those in vitro:celecoxib combinedwith cisplatin slowed tumor growth in wild-type p53 groups and not in mutated or deleted p53 groups.In addition,celecoxib promoted p53 translocation into the nucleus and upregulated active p53 expression in wild-type p53 cells.Celecoxib combined with cisplatin upregulated PUMA(PUMA is a downstream gene of p53)after active p53 increased in wild-type p53 cells.In summary,the combination of celecoxib and cisplatin demonstrates clear synergistic effects in wild-type p53 cells and antagonistic effects inmutated or deleted p53 cells.The synergistic effect was achieved by apoptosis,induced by upregulating PUMA.Our results will provide a new treatment strategy for patients carrying wild-type p53,insensitive to cisplatin.

Downregulation of wild-type p53 protein by HER-2/neu mediated PI3K pathway activation in human breast cancer cells: its effect on cell proliferation and implication for therapy

Overexpression and activation of HER-2/neu (also known as c-erbB-2), a proto-oncogene, was found in about 30% of human breast cancers, promoting cancer growth and making cancer cells resistant to chemo- and radio-therapy. Wild-type p53 is crucial in regulating cell growth and apoptosis and is found to be mutated or deleted in 60-70% of human cancers. And some cancers with a wild-type p53 do not have normal p53 function, suggesting that it is implicated in a complex process regulated by many factors. In the present study, we showed that the overexpression of HER-2/neu could decrease the amount of wild-type p53 protein via activating PI3K pathway, as well as inducing MDM2 nuclear translocation in MCF7 human breast cancer cells. Blockage of PI3K pathway with its specific inhibitor LY294002 caused Gl-S phase arrest, decreased cell growth rate and increased chemo- and radio-therapeutic sensitivity in MCF7 cells expressing wild-type p53. However, it did not increase the sensitivity to adriamycin in MDA-MB-453 breast cancer cells containing mutant p53. Our study indicates that blocking PI3K pathway activation mediated by HER-2/neu overexpression may be useful in the treatment of breast tumors with HER-2/neu overexpression and wild-type p53.

Double Lethal Effects of Fusion Gene of Wild-type p53 and JunB on Hepatocellular Carcinoma Cells

This study explored the double lethal effects of pEGFP-C1-wtp53/junB fusion gene on hepatocellular carcinoma (HCC) cells.wtp53/junB fusion gene was constructed and transformed into HepG2 cell line.Expression of KAI1 was detected by quantitative real-time PCR and Western blotting,cells apoptosis rate was detected by flow cytometry,proliferation of cells was detected by MTT chromometry,cell transmigration was detected by using transwell systems.The results showed that after transformation with pEGFP-C1-wtp53/JunB,the expression level of KAI1 protein was up-regulated,being 8.13 times the blank control group in HepG2 cells and significantly higher than 2.87 times which transformed with pEGFP-C1-JunB,3.11 times which transformed with pEGFP-C1-wtp53 (P<0.001).Apoptosis rate of HepG2 cells transformed with pEGFP-C1-wtp53/JunB was significantly higher than that of other groups (P<0.001),and invasive ability of HepG2 cells transformed with pEGFP-C1-wtp53/JunB was significantly lower than other groups (P<0.001).It was concluded that the fusion gene of wtp53 and JunB could not only inhibit the growth of hepatoma cells and promote tumor cell apoptosis,but also suppress the invasive ability of tumor cells by up-regulating the expression of KAI1.

Synergetic anticancer effect of combined quercetin and recombinant adenoviral vector expressing human wild-type p53,GM-CSF and B7-1 genes on hepatocellular carcinoma cells in vitro

AIM: This study investigated the anti-cancer effect ofcombined quercetin and a recombinant adenovirus vectorexpressing the human p53, GM-CSF and B7-1 genes(designated BB-102) on human hepatocellular carcinoma(HCC) cell lines in vitro.METHODS: The sensitivity of HCC cells to anticancer agentswas evaluated by 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The viability of cells infectedwith BB-102 was determined by trypan blue exclusion. Theexpression levels of human wild-type p53, GM-CSF and B7-1genes were determined by Western blot, enzyme-linkedimmunosorbent assay (ELISA) and flow cytometric analysis,respectively. The apoptosis of BB-102-infected or quercetin-treated HCC cells was detected by terminal deoxynucleotidyltransferase (TdT) assay or DNA ladder electrophoresis.RESULTS: Quercetin was found to suppress proliferation ofhuman HCC cell lines BEL-7402, HUH-7 and HLE, with peaksuppression at 50 μmol/L quercetin. BB-102 infection wasalso found to significantly suppress proliferation of HCC celllines. The apoptosis of BB-102-infected HCC cells was greaterin HLE and HUH-7 cells than in BEL-7402 cells. Quercetin didnot affect the expression of the three exogenous genes inBB-102-infected HCC cells (P＞0.05), but it was found to furtherdecrease proliferation and promote apoptosis of BB-102-infected HCC cells.CONCLUSION: BB-102 and quercetin synergeticallysuppress HCC cell proliferation and induce HCC cell apoptosis,suggesting a possible use as a combined anti-cancer agent.

Synergistic anticancer effect of exogenous wild-type p53 gene combined with 5-FU in human colon cancer resistant to 5-FU in vivo

AIM To investigate the anticancer effect of a recombinant adenovirus-mediated p53(r Ad-p53) combined with 5-fluorouracil(5-FU) in human colon cancer resistant to 5-FU in vivo and the mechanism of r Ad-p53 in reversal of 5-FU resistance.METHODS nude mice bearing human colon cancer SW480/5-FU(5-FU resistant) were randomly assigned to four groups(n = 25 each): control group, 5-FU group, r Ad-p53 group, and r Ad-p53 + 5-FU group. At 24 h, 48 h, 72 h, 120 h and 168 h after treatment, 5 mice were randomly selected from each group and sacrificed using an overdose of anesthetics. The tumors were removed and the protein expressions of p53, protein kinase C(PKC), permeability-glycoprotein(P-gp) and multidrug resistance-associated protein 1(MRP1)(Western blot) and apoptosis(TUNEL) were determined.RESULTS The area ratios of tumor cell apoptosis were larger in the r Ad/p53 + 5-FU group than that in the control, 5-FU and r Ad/p53 groups(P < 0.05), and were larger in the r Ad/p53 group than that of the control group(P < 0.05) and the 5-FU group at more than 48 h(P < 0.05). The p53 expression was higher in the r Ad/p53 and the r Ad/p53 + 5-FU groups than that of the control and 5-FU groups(P < 0.05), and were higher in the r Ad/p53 + 5-FU group than that of the r Ad/p53 group(P < 0.05). Overexpression of PKC, P-gp and MRP1 was observed in the 5-FU and control groups. In the r Ad/p53 + 5-FU group, the expression of P-gp and MRP1 was lower that of the control and 5-FU groups(P < 0.05), and the expression of PKC was lower than that of the control, 5-FU and r Ad/p53 groups at more than 48 h(P < 0.05). In the r Ad/p53 group, the expression of P-gp and MRP1 was lower that of the control and 5-FU groups at more than 48 h(P < 0.05), and the expression of PKC was lower than that of the control and 5-FU groups at more than 120 h(P < 0.05).CONCLUSION5-FU combined with r Ad-p53 has a synergistic anticancer effect in SW480/5-FU(5-FU resistance), which contributes to reversal of 5-FU resistance.

Effects of dendritic cells transfected with full-length wild-type p53 and stimulated by gastric cancer lysates on immune response

AIM: To investigate the effects of dendritic cells (DCs) transfected with full-length wild-type p53 and stimulated by gastric cancer lysates on immune response.METHODS: The wild-type p53 was transduced to DCs with adenovirus, and the DCs were stimulated by gastric cancer lysates. The surface molecules (B7-1, B7-2, MHC-I, MHC-II) of all DCs were detected by FACS, and the ability of the DCs to induce efficient and specific immunological response inanti-^51Cr-labeled target cells was studied. BALB/c mice injected with DCs and Mk28 were established, and CTL response in mice immunized with Lywt-p53DC was evaluated.Tumor-bearing mice were treated with Lywt-p53DC.RESULTS: The surface molecules of Lywt-p53DC had a high expression of B7-1 (86.70±0.07%), B7-2 (18.77±0.08%),MHC-I (87.20±0.05%) and MHC-II (56.70±0.07%); T lymphocytes had a specific CTL lysis ability induced by Lywt-p53DC; the CTL lysis rate was as high as 81%. The immune protection of Lywtp-53DC was obvious, the tumor diameter in Lywtp-53DC group was 3.10+0.31 ram, 2.73±0.23 ram,3.70±0.07 mm on d 13, 16 and 19, respectively, which were smaller than control, DC, wtp53DC and LyDC group (P<0.05). Tumor growth rate in Lywtp53DC group was slower than that in other groups (P<0.05).CONCLUSION: DCs transfected with wild-type p53 and stimulated by gastric cancer lysates have specific CTL killing activity.

Reversal of 5-flouroucial resistance by adenovirus-mediated transfer of wild-type p53 gene in multidrug-resiatant human colon carcinoma LoVo/5-FU cells

AIM: To observe the reversal effects of wide-type p53 gene on multi-drug resistance to 5-FU (LOVO/5-FU).METHODS: After treatment with Ad-p53, LOVO/5-FU sensitivity to 5-Fu was investigated using tetrazolium dye assay. Multidrug resistance gene-1 (MDR1) gene expression was assayed by semi-quantitative reverse transcriptionpolymerase chain reaction and the expression of p53 protein was examined by Western blotting.RESULTS: The reversal activity after treatment with wide type p53 gene was increased up to 4.982 fold at 48 h. The expression of MDR1 gene decreased significantly after treatment with wide-type p53 gene, and the expression of p53 protein lasted for about 5 d, with a peak at 48 h, and began to decrease at 72 h.CONCLUSION: Wide-type p53 gene has a remarkable reversal activity for the high expression of MDR1 gene in colorectal cancers. The reversal effects seem to be in a time dependent manner. It might have good prospects in clinical application.

The effect of adenovirus expressing wild-type p53 on 5-fluorouracil chemosensitivity is related to p53 status in pancreatic cancer cell lines

AIM:There are conflicting data about p53 function on cellular sensitivity to the cytotoxic action of 5-fluorouracil (5-FU). Therefore the objective of this study was to determine the combined effects of adenovirus-mediated wild-type (wt) p53 gene transfer and 5-FU chemotherapy on pancreatic cancer cells with different p53 gene status. METHODS:Human pancreatic cancer cell lines Capan-1^(p53mut), Capan-2^(p53wt),FAMPAC^(p53mut),PANC1^(p53mut),and rat pancreatic cancer cell lines AS^(p53wt) and DSL6A^(p53null) were used for in vitro studies.Following infection with different ratios of Ad- p53-particles (MOI) in combination with 5-FU,proliferation of tumor cells and apoptosis were quantified by cell proliferation assay (WST-1) and FACS (PI-staining).In addition,DSL6A syngeneic pancreatic tumor cells were inoculated subcutaneously in to Lewis rats for in vivo studies. Tumor size,apoptosis (TUNEL) and survival were determined. RESULTS:Ad-p53 gene transfer combined with 5-FU significantly inhibited tumor cell proliferation and substantially enhanced apoptosis in all four cell lines with an alteration in the p53 gene compared to those two cell lines containing wt-p53.In vivo experiments showed the most effective tumor regression in animals treated with Ad-p53 plus 5-FU.Both in vitro and in vivo analyses revealed that a sublethal dose of Ad-p53 augmented the apoptotic response induced by 5-FU. CONCLUSION:Our results suggest that Ad-p53 may synergistically enhance 5-FU-chemosensitivity most strikingly in pancreatic cancer cells lacking p53 function.These findings illustrate that the anticancer efficacy of this combination treatment is dependent on the p53 gene status of the target tumor cells.

Effect of Wild-type p53 Gene Transfection on the Growth and Radiotherapeutic Sensitivity of Human Glioma Cells

Summary： To evaluate the effect of wild type p53 gene on the growth and radiotherapeutic sensitivity of human glioma cells, plasmid PC53 SN3 carrying wild type p53 gene was transfected into U251 cells, p53 gene expression in transfected cells was detected by RT PCR, and the cell growth inhibition and apoptosis in the absence or presence of irradiation were assessed by MTT and flow cytometry. The transfection of p53 gene into U251 cells was confirmed by RT PCR. MTT showed that p53 gene alone induced strong inhibitory effect on the growth of U251 cells （inhibition rate （IR）： （79.60±5.69）%）, The killing effect of irradiation alone on U251 cells was not strong （IR： （17. 06±4.35）%, （17.39±1.67）%, （18.73±4.68）%） and increased with the irradiation doses （3, 6, 9 Gy）. When combined treatment of wild-type p53 gene transfection and irradiation was used, the effect was significantly increased （IR：（80.60±5.35）%, （90.30＋1.67） %, （91.30±2.01） %）. Theapoptosis rate of U251 cells induced by p53 gene transfectionwas 17.38 %. The rate induced by irradiation increased （4. 61%, 4. 84%, 5. 40 %） with the irradiation doses （3, 6, 9 Gy）. Theapoptosis rate was also significantly increased （17.80%, 20.03%, 22.34%） after combined treatment of p53 and irradiation with different doses （3, 6, 9 Gy）. It is concluded that wildtype p53 gene and irradiation could result in synergistic inhibitory effect on the growth of human glioma cells.

Wild-type p53-induced Phosphatase I Deficiency Exacerbates Myocardial Infarction-induced Ischemic Injury

Background： Myocardial infarction （MI） is a major disease burden. Wild-type p53-induced phosphatase 1 （Wipl） has been studied extensively in the context of cancer and the regulation of different types of stem cells, but the role of Wipl in cardiac adaptation to M I is unknown. We investigated the significance of Wipl in a mouse model of MI. Methods： The study began in June 2014 and was completed in July 2016. We compared Wipl-knockout （Wipl-KO） mice and wild-type （WT） mice to deternline changes in cardiac function and survival in response to MI. The heart weight/body weight （HW/BW） ratio and cardiac function were measured before MI. Mouse MI was established by ligating the left anterior descending （LAD） coronary artery under 1.5% isoflurane anesthesia. After M1, survival of the mice was observed for 4 weeks. Cardiac function was examined by echocardiography. The HW/BW ratio was analyzed, and cardiac hypertrophy was measured by wheat germ agglutinin staining. Hematoxylin and eosin （H＆E） staining was used to determine the infarct size. Gene expression of interleukin-6 （IL-6）, turnor necrosis factor-α （TNF-α）, and interleukin-1β （IL-1β） was assessed by quantitative real-time polymerase chain reaction （qPCR）, and the levels of signal transducers and activators of transcription 3 （stat3） and phosphor-stat3 （p-stat3） were also analyzed by Western blotting. Kaplan-Meier survival analysis, log-rank test, unpaired l-test, and one-way analysis of variance （ANOVA） were used for statistical analyses. Results： Wipl-KO mice had a marginally increased HW/BW ratio and slightly impaired cardiac fiinction before LAD ligation. Alter MI, Wipl-deficient mice exhibited increased mortality （57.14% vs. 29.17%; n = 24 [WT], n - 35 [WipI-KO], P 〈 0.05）, increased cardiac hypertrophy （HW/BW ratio： 7 days： 7.25±0.36 vs. 5.84 ± 0.18, n cross-sectional area： 7 days： 311.80 ± 8.29 vs. 268.90 ± 11.15, n P 〉 0.05）, and reduced cardiac function （ejection fraction： 7 days 10, p〈 0.01, and 4 weeks： 6.05± 0.17 vs. 5.87 ±0.24, n= 10, P〉0.05; P 〈 0.05, and 4 weeks： 308.80 ± 11.26 vs. 317.00 ±13.55, n = 6 29.37± 1.38 vs. 34.72 ± 1.81, P 〈 0.05, and 4 weeks： 19.06 ± 2.07 vs 26.37 ± 2.95, P〈 0.05; fractional shortening： 7 days： 13.72 ± 0.71 vs. 16.50 ± 0.94, P〈 0.05, and 4 weeks： 8.79 ±1.00 vs. 12.48 ±1.48, P 〈 0.05; n = l0 [WT], n = 15 [Wipl-KO]）. H＆E staining revealed a larger infarct size in Wipl-KO mice than in WT mice （34.79% ± 2.44% vs. 19.55% ± 1.48%, n = 6, P 〈 0.01 ）. The expression oflL-6 and p-stat3 was downregulated in Wipl-KO mice （IL-6：1.71 ± 0.27 vs. 4.46 ± 0.79, n = 6, P 〈 0.01 ; and p-stat3/stat3：1.15 ±0.15 vs. 1.97 ± 0.23, n = 6, P 〈 0.05）. Conclusion： The results suggest that Wipl could protect the heart from MI-induced ischemic injury.

Expression rates of p16,p53 in head and neck cutaneous squamous cell carcinoma based on human-papillomavirus positivity

BACKGROUND The high prevalence of human papillomavirus(HPV)infection in oropharyngeal squamous cell carcinoma(SCC)is well established,and p16 expression is a strong predictor.HPV-related tumors exhibit unique mechanisms that target p16 and p53 proteins.However,research on HPV prevalence and the combined predictive value of p16 and p53 expression in head and neck cutaneous SCC(HNCSCC),particularly in Asian populations,remains limited.This retrospective study surveyed 62 patients with HNSCC(2011-2020),excluding those with facial warts or other skin cancer.AIM To explore the prevalence of HPV and the predictive value of p16 and p53 expression in HNCSCC in Asian populations.METHODS All patients underwent wide excision and biopsy.Immunohistochemical staining for HPV,p16,and p53 yielded positive and negative results.The relevance of each marker was investigated by categorizing the tumor locations into high-risk and middle-risk zones based on recurrence frequency.RESULTS Of the 62 patients,20(32.26%)were male,with an average age of 82.27 years(range 26-103 years).High-risk included 19 cases(30.65%),with the eyelid and lip being the most common sites(five cases,8.06%).Middle-risk included 43 cases(69.35%),with the cheek being the most common(29 cases,46.77%).The p16 expression was detected in 24 patients(38.71%),p53 expression in 42 patients(72.58%),and HPV in five patients(8.06%).No significant association was found between p16 expression and the presence of HPV(P>0.99),with a positive predictive value of 8.33%.CONCLUSION This study revealed that p16,a surrogate HPV marker in oropharyngeal SCC,is not reliable in HNCSCC,providing valuable insights for further research in Asian populations.

Maspin subcellular expression in wild-type and mutant TP53 gastric cancers

BACKGROUND Although the role of p53 in the evolution and prognosis of gastric cancer(GC)has been extensively examined,the exact mechanism of action is incompletely understood.In the last years,p53-target genes were supposed to be involved in the p53 pathway.One of them is the tumor-suppressor gene Maspin,which codifies the protein with the same name.Maspin activity depends on its subcellular localization.To our knowledge,the possible role of TP53 gene in Maspin subcellular localization,in GC cells,has not yet been studied in a large number of human samples.AIM To evaluate the possible role of wild-type and mutated p53 in Maspin subcellular localization.METHODS The present study included 266 consecutive patients with GC in which TP53 gene status,and mutations in exons 2 to 11,respectively,were analyzed and correlated with immunohistochemical expression of p53 and Maspin.RESULTS None of the 266 cases showed mutations in exon 9.The rate of TP53 mutations was 33.83%.The mutation rate was slightly higher in distally-located GCs,with a lower degree(≤5 buds/high power fields)of dyscohesivity(P<0.01).The wildtype cases had a longer survival,compared with mutant GCs,especially in patients without lymph node metastases,despite the high depth of tumor infiltration(P=0.01).The Dukes-MAC-like staging system was proved to have the most significant independent prognostic value(P<0.01).The statistical correlations proved that TP53 gene mutations in exon 7 might induce knockdown of Maspin,but wild-type p53 can partially restore nuclear Maspin expression and decrease the metastatic potential of gastric adenocarcinoma cells.CONCLUSION Downregulated Maspin might be induced by mutations in exon 7 of the TP53 gene but wild-type p53 can partially restore nuclear Maspin expression.These findings should be proved in experimental studies.

An iASPP-derived short peptide restores p53-mediated cell death in cancers with wild-type p53

Background:Inhibitor of apoptosis-stimulating protein of p53(iASPP)is an evolutionarily conserved p53 inhibitor.Mechanistically,iASPP can accelerate tumorigenesis by inhibiting the transactivation function of p53.Targeting the interaction between iASPP and p53 may be a potential therapy for restoring the activity of p53 in tumors.Methods:We constructed an iASPP-derived peptide,called A8,that was derived from the C-terminus of iASPP.Here,we transfected A8 into two wildtype(WT)p53 cell lines,U2OS and A549,and then determined the number of apoptotic cells.The mechanism by which A8 affected apoptosis was further examined by immunoprecipitation(IP),Dual-Luciferase reporter assays,and chromatin IP assays.Real-time polymerase chain reaction and western blots were also used to examine the expression levels of apoptosis-related factors.Results:Our data demonstrate that A8 can increase apoptosis rates in WT p53 cell lines.Functional analysis suggested that A8 restored the transcriptional function and DNA binding activities of p53 toward the Bax and PUMA gene promoters.Moreover,A8 reduced cell proliferation and inhibited tumor growth in xenograft nude mice.Conclusions:These data provide a new approach for restoring the tumor suppressor function of p53 in cancer cells that express WT p53 and therefore may serve as a novel cancer treatment strategy.

ADENOVIRUS-MEDIATED WILD-TYPE P53 EXPRESSION SUPPRESSES GROWTH OF LUNG ADENOCARCINOMA CELLS

Objective: To study the growth suppression of lung adenocarcinoma cell by the introduction of wild type P53 gene and explore a gene therapy approach for lung adenocarcinoma. Methods: A replication deficient adeno virus vector encoding a wild type P53 was constructed and transfected into the cultured human lung adeno carcinoma cell line GLC 82. The efficiency of gene transfection and expression was detected by immuno chemical staining and polymerase chain reaction. The cell growth rate and cell cycle were analysed by cell counting and flow cytometry. Results: Wild type P53 gene could be quickly and effectively transfected into the cells by adenovirus vector. Wild type P53 expression could inhibit GLC 82 cell proliferation and induce apoptosis. Conclusion: The results indicated that recombinant adenovirus expressing wild type P53 might be useful vector for gene therapy of human lung adenocarcinoma.

MDM2 antagonist Nutlin-3a protects wild-type p53 cancer cells from paclitaxel

The p53 pathway has an important role in cell cycle arrest and apoptosis.Downregulated levels of p53 have been shown to increase resistance to the cytotoxic effects of chemotherapy or radiotherapy.MDM2(murine double minute 2) is able to bind p53 and modulate its transcriptional activity and stability.We studied the effect of Nutlin-3a,an MDM2 antagonist,on the response of non-small cell lung cancer cell lines,A549(p53+/+) and H1299(p53-/-),to paclitaxel(Taxol).A549 cells treated with Nutlin-3a plus paclitaxel showed a significant increase in MDM2 and wild-type p53 protein,a marked increase in the number of cells in the G0-G1 and G2-M phases,and a significant decrease in the percentage of cells in the S phase.The percentage of apoptotic A549 cells treated with 10 μmol/L Nutlin-3a plus 10 nmol/L paclitaxel was significantly lower than those treated with paclitaxel alone,and was also lower than that observed in H1299 cells.MTT assays demonstrated that Nutlin-3a plus paclitaxel also significantly reduced the sensitivity of A549 cells to paclitaxel compared with that of H1299 cells.In conclusion,Nutlin-3a mediates the cytotoxic effect of paclitaxel depending on p53 status.It may also protect wild-type p53 cells from mitotic chemotherapeutics.

芍药苷调节丝氨酸/苏氨酸激酶/鼠双微基因2/p53信号通路对弥漫大B细胞淋巴瘤细胞增殖、凋亡和细胞周期的影响实验研究

目的:探讨芍药苷(PAE)调节丝氨酸/苏氨酸激酶(AKT)/鼠双微基因2(MDM2)/p53信号通路对弥漫大B细胞淋巴瘤(DLBCL)细胞增殖、凋亡和细胞周期的影响。方法:以OCI-LY3细胞为研究对象,分别设置PAE低浓度组(15μmol/L PAE)、PAE中浓度组(30μmol/L PAE)、PAE高浓度组(60μmol/L PAE)、PAE高浓度+SC79(AKT激活剂)组(60μmol/L PAE+8μg/ml SC79),同时以未经处理的细胞为对照组。48 h后,分析细胞增殖、克隆形成能力及细胞周期和凋亡变化,检测AKT/MDM2/p53信号通路相关蛋白的表达水平。结果:与对照组比较,PAE低浓度组、PAE中浓度组、PAE高浓度组细胞凋亡率、p53表达、G_(0)/G_(1)期增加,细胞克隆形成数和细胞增殖率,p-AKT/AKT和p-MDM2/MDM2表达水平,以及G_(2)/M、S期降低(均P<0.05)。与PAE高浓度组比较,PAE高浓度+SC79组细胞凋亡率、p53表达、G_(0)/G_(1)期降低,细胞克隆形成数和细胞增殖率,p-AKT/AKT和p-MDM2/MDM2表达水平,以及G_(2)/M、S期增加(均P<0.05)。结论:PAE通过抑制AKT/MDM2上调p53表达,抑制DLBCL细胞增殖、细胞周期进展,诱导其凋亡。

胃癌组织中KAI1/CD82、p27和p53的表达水平及其临床意义

目的研究胃癌组织中KAI1/CD82、p27、p53蛋白的表达水平及其临床意义。方法收集中南大学湘雅医学院附属海口医院胃肠外科2020年6月至2021年6月期间接受胃癌切除术治疗的43例胃癌患者标本,将标本分为43例胃癌组、43例配对的癌旁组(距癌2 cm)和43例配对的正常组(距癌5 cm以上),运用免疫印迹(Western blot)方法检测并比较三组组织中的KAI1/CD82、p27、p53蛋白表达水平,分析胃癌组织中KAI1/CD82、p27、p53的表达水平与临床病理参数的关系,采用Pearson相关分析法分析其与胃癌的临床病理特征的关系。结果胃癌组中的KAI1/CD82、p27、p53蛋白表达水平明显低于癌旁组和正常组,且癌旁组明显低于正常组,差异均有统计学意义(P<0.05);KAI1/CD82、p27、p53蛋白的阳性表达率与肿瘤组织的分化程度、临床分期和淋巴结是否转移有关(P<0.05),而与年龄、性别无关(P>0.05);经Pearson相关分析结果显示,胃癌组织中KAI1/CD82与p27蛋白和p53蛋白的表达均呈正相关(r=0.586、0.426,P<0.05)。结论胃癌组织中的KAI1/CD82、p27、p53蛋白表达水平明显降低,联合检测KAI1/CD82、p27、p53可能成为胃癌诊断及预后评估的新的分子标记物。

USP7-MDM2-p53信号轴对子宫内膜癌细胞增殖、凋亡和细胞周期的影响

目的:探讨泛素特异性蛋白酶7(USP7)调节Mdm2 p53结合蛋白同源物(MDM2)-p53轴对子宫内膜癌细胞增殖、凋亡和细胞周期的影响。方法:Western blot检测人子宫内膜癌组织、癌旁组织、人子宫内膜上皮细胞hEEC及人子宫内膜癌细胞系Ishikawa、HEC-1-A、KLE中USP7蛋白表达。将Ishikawa细胞分为NC组、P22077(USP7抑制剂)组、pcDNA组、pcDNA-MDM2组、P22077+pcDNA组、P22077+pcDNA-MDM2组,CCK-8法和克隆形成实验检测Ishikawa细胞增殖;流式细胞术检测Ishikawa细胞凋亡与细胞周期变化;Western blot检测Ishikawa细胞中USP7、细胞周期蛋白D1(CyclinD1)、周期素依赖性激酶2(CDK2)、Bcl-2相关X蛋白(Bax)、MDM2、p53蛋白表达。以RG7388(MDM2抑制剂)或PFT-α(p53抑制剂)与20μmol/L P22077共处理Ishikawa细胞48 h以验证USP7-MDM2-p53信号轴上下游关系。结果:USP7蛋白在子宫内膜癌组织和细胞中高表达,且Ishikawa细胞中USP7蛋白表达量最高,因此,选择Ishikawa细胞为研究对象。与NC组比较,P22077组Ishikawa细胞OD 450值、克隆形成率、S期和G 2/M期细胞数、USP7、CyclinD1、CDK2、MDM2蛋白表达降低,细胞凋亡率、G_(0)/G_(1)期细胞数、p53、Bax蛋白表达升高(P<0.05);与NC组、pcDNA组比较,pcDNA-MDM2组Ishikawa细胞OD 450值、克隆形成率、S期和G 2/M期细胞数、USP7、CyclinD1、CDK2、MDM2蛋白表达升高,细胞凋亡率、G_(0)/G_(1)期细胞数、p53、Bax蛋白表达降低(P<0.05);与P22077组、P22077+pcDNA组比较,P22077+pcDNA-MDM2组Ishikawa细胞OD 450值、克隆形成率、S期和G 2/M期细胞数、USP7、CyclinD1、CDK2、MDM2蛋白表达升高,细胞凋亡率、G_(0)/G_(1)期细胞数、p53、Bax蛋白表达降低(P<0.05)。p53为USP7-MDM2通路下游分子。结论:抑制USP7表达可能通过下调MDM2来激活p53进而抑制Ishikawa细胞增殖、促进细胞凋亡及周期停滞。

结合网络药理学分析p53信号通路在麦门冬汤改善肺纤维化小鼠模型中的作用

目的探讨麦门冬汤对肺纤维化小鼠模型的干预作用及其药理机制。方法将C57BL/6小鼠随机分成对照组、模型组、干预组,每组6只,模型组小鼠经气管滴注博来霉素建立肺纤维化小鼠模型,干预组造模24 h后麦门冬汤灌胃给药20 d,观察小鼠一般情况,HE染色观察肺组织的病理变化,免疫组化和Western blot分析α-平滑肌肌动蛋白(alpha smooth muscle actin,α-SMA)和钙黏蛋白(epithelial cadherin,E-cadherin)的表达情况。网络药理分析麦门冬汤干预肺纤维化的潜在机制。其后通过转化生长因子(transforming growth factor,TGF)-β1诱导小鼠胚胎成纤维细胞NIH3T3构建肺纤维化细胞模型,麦门冬汤含药血清和(或)p53抑制剂(pifithrin-α,PFT-α)干预后,荧光定量PCR和Western blot检测p53、α-SMA、E-cadherin和I型胶原蛋白(collagen type I,Collagen I)的表达情况。结果与对照组比较,肺纤维化小鼠模型肺组织均出现大面积实变区和大量炎性细胞浸润,α-SMA表达增加,E-cadherin降低(P<0.01),麦门冬汤干预后上述症状得到显著改善。网络药理学分析发现麦门冬汤的差异药靶基因主要富集在p53信号通路。细胞实验则显示麦门冬汤组含药血清干预可使肺纤维化细胞模型中α-SMA下调,E-cadherin和p53表达上调(P<0.01)。PFT-α干预实验中,PFT-α干预后对照组和麦门冬汤组中p53和E-cadherin表达降低,α-SMA和Collagen I表达升高(P<0.01)。结论麦门冬汤可通过调节p53信号通路改善肺纤维化进展。