RBMX通过下调PKM2抑制膀胱癌细胞的增殖、迁移、侵袭和糖酵解

目的探讨X连锁RNA结合基序蛋白(RBMX)对膀胱癌细胞(1376细胞和UC-3细胞)的增殖、迁移、侵袭的影响以及其在糖酵解中的作用。方法采用慢病毒表达系统和siRNA干扰技术,分别构建RBMX过表达和敲低的膀胱癌细胞模型(1376细胞和UC-3细胞)。采用RT-qPCR和Westernblotting分别在mRNA水平和蛋白水平上检测细胞模型是否构建成功。通过EdU增殖实验和克隆形成实验检测过表达和敲低RBMX后细胞的生长和集落形成能力,同时通过Transwell实验分析过表达和敲低RBMX后对细胞迁移、侵袭能力的影响;随后,采用Westernblotting检测过表达和敲低RBMX后糖酵解关键蛋白PKM1(M1型丙酮酸激酶)和PKM2(M2型丙酮酸激酶)的表达变化;最后,利用葡萄糖和乳酸检测试剂盒分析过表达和敲低RBMX对膀胱癌细胞糖酵解的影响。结果RT-qPCR和Westernblotting结果显示,过表达RBMX膀胱癌细胞的mRNA和蛋白表达水平显著高于阴性对照组(P<0.05),敲低RBMX膀胱癌细胞的mRNA和蛋白表达水平显著低于阴性对照组(P<0.05)。过表达RBMX明显抑制膀胱癌细胞的增殖、克隆形成、迁移和侵袭,敲低RBMX则作用相反。Westernblotting实验结果显示,过表达RBMX使PKM1表达上升,PKM2表达下降,敲低RBMX则作用相反。葡萄糖消耗及乳酸生成实验表明,过表达RBMX均能抑制膀胱癌细胞葡萄糖消耗及乳酸生成(P<0.05),敲低RBMX均能促进膀胱癌细胞葡萄糖消耗及乳酸生成(P<0.05)。结论RBMX通过下调PKM2抑制膀胱癌的发生发展和糖酵解能力,有望成为膀胱癌诊断和治疗的潜在分子靶标。

血清PKM2、NRF2与宫颈癌患者临床病理特征和预后的关系

目的 探讨血清丙酮酸激酶M2型(PKM2)、核因子E2相关因子2(NRF2)与宫颈癌患者临床病理特征和预后的关系。方法 选取2016年1月至2018年1月安阳市肿瘤医院收治的宫颈癌患者92例为宫颈癌组,另选取同期体检健康女性55例为对照组。采用酶联免疫吸附法检测患者血清PKM2、NRF2水平,分析血清PKM2、NRF2水平与宫颈癌患者临床病理特征的关系。采用Kaplan-Meier(K-M)法绘制生存曲线,探讨血清PKM2、NRF2水平与宫颈癌患者预后的关系。绘制受试者工作特征(ROC)曲线分析血清PKM2、NRF2水平预测宫颈癌患者预后不良的价值。结果 宫颈癌组血清PKM2、NRF2水平高于对照组(P<0.001)。血清PKM2、NRF2水平与宫颈癌患者分化程度、FIGO分期、淋巴结转移有关(P<0.05)。随访5 a, 92例宫颈癌患者5 a总生存率为61.96%(57/92)。K-M生存曲线分析显示,PKM2、NRF2高水平组总生存率低于PKM2、NRF2低水平组(P<0.05)。ROC曲线分析显示,血清PKM2、NRF2水平联合预测宫颈癌患者预后不良的曲线下面积为0.878,大于血清PKM2、NRF2水平单独预测的0.791,0.780。结论 宫颈癌患者血清PKM2、NRF2水平呈异常高表达,其与恶性临床病理特征有关,可能成为宫颈癌患者预后不良的辅助预测指标。

Signal transducer and activator of transcription 3 promotes the Warburg effect possibly by inducing pyruvate kinase M2 phosphorylation in liver precancerous lesions

BACKGROUND Study shows that signal transducer and activator of transcription 3(STAT3) can increase the Warburg effect by stimulating hexokinase 2 in breast cancer and upregulate lactate dehydrogenase A and pyruvate dehydrogenase kinase 1 in myeloma. STAT3 and pyruvate kinase M2(PKM2) can also be activated and enhance the Warburg effect in hepatocellular carcinoma. Precancerous lesions are critical to human and rodent hepatocarcinogenesis. However, the underlying molecular mechanism for the development of liver precancerous lesions remains unknown. We hypothesized that STAT3 promotes the Warburg effect possibly by upregulating p-PKM2 in liver precancerous lesions in rats.AIM To investigate the mechanism of the Warburg effect in liver precancerous lesions in rats.METHODS A model of liver precancerous lesions was established by a modified Solt-Farber method. The liver pathological changes were observed by HE staining and immunohistochemistry. The transformation of WB-F344 cells induced with Nmethyl-N'-nitro-N-nitrosoguanidine and hydrogen peroxide was evaluated by the soft agar assay and aneuploidy. The levels of glucose and lactate in the tissue and culture medium were detected with a spectrophotometer. The protein levels of glutathione S-transferase-π, proliferating cell nuclear antigen(PCNA), STAT3,and PKM2 were examined by Western blot and immunofluorescence.RESULTS We found that the Warburg effect was increased in liver precancerous lesions in rats. PKM2 and p-STAT3 were upregulated in activated oval cells in liverprecancerous lesions in rats. The Warburg effect, p-PKM2, and p-STAT3 expression were also increased in transformed WB-F344 cells. STAT3 activation promoted the clonal formation rate, aneuploidy, alpha-fetoprotein expression,PCNA expression, G1/S phase transition, the Warburg effect, PKM2 phosphorylation, and nuclear translocation in transformed WB-F344 cells.Moreover, the Warburg effect was inhibited by stattic, a specific inhibitor of STAT3, and further reduced in transformed WB-F344 cells after the intervention for PKM2.CONCLUSION The Warburg effect is initiated in liver precancerous lesions in rats. STAT3 activation promotes the Warburg effect by enhancing the phosphorylation of PKM2 in transformed WB-F344 cells.

Tumor pyruvate kinase M2:A promising molecular target of gastrointestinal cancer

Gastrointestinal(GI) cancer is one of the most common causes of cancer-related deaths worldwide.Tumor markers are valuable in detecting post-surgical recurrence or in monitoring response to chemotherapy.Pyruvate kinase isoform M2(PKM2),a glycolytic enzyme catalyzing conversion of phosphoenolpyruvate(PEP) to pyruvate,confers a growth advantage to the tumor cells and enables them to adapt to the tumor microenvironment.In this review,we have summarized current research on the expression and regulation of PKM2 in tumor cells,and its potential role in GI carcinogenesis and progression.Furthermore,we have also discussed the potential of PKM2 as a diagnostic and screening marker,and a therapeutic target in GI cancer.

Overexpression of the M2 isoform of pyruvate kinase is an adverse prognostic factor for signet ring cell gastric cancer

AIM:To investigate M2 isoform of pyruvate kinase(PKM2) expression in gastric cancers and evaluate its potential as a prognostic biomarker and an anticancer target.METHODS:All tissue samples were derived from gastric cancer patients underwent curative gastrectomy as a primary treatment.Clinical and pathological information were obtained from the medical records.Gene expression microarray data from 60 cancer and 19 noncancer gastric tissues were analyzed to evaluate the expression level of PKM2 mRNA.Tissue microarrays were constructed from 368 gastric cancer patients.Immunohistochemistry was used to measure PKM2 expression and PKM2 positivity of cancer was determined by proportion of PKM2-positive tumor cells and staining intensity.Association between PKM2 expression and the clinicopathological factors was evaluated and the correlation between PKM2 and cancer prognosis was evaluated.RESULTS:PKM2 mRNA levels were increased more than 2-fold in primary gastric cancers compared to adjacent normal tissues from the same patients(log transformed expression level:7.6 ± 0.65 vs 6.3 ± 0.51,P < 0.001).Moreover,differentiated type cancers had significantly higher PKM2 mRNA compared to undifferentiated type cancers(log transformed expression level:7.8 ± 0.70 vs 6.7 ± 0.71,P < 0.001).PKM2 protein was mainly localized in the cytoplasm of primary cancer cells and detected in 144 of 368(39.1%) human gastric cancer cases.PKM2 expression was not related with stage(P = 0.811),but strongly correlated with gastric cancer differentiation(P < 0.001).Differentiated type cancers expressed more PKM2 protein than did the undifferentiated ones.Well differentiated adenocarcinoma showed 63.6% PKM2-positive cells;in contrast,signet-ring cell cancers showed only 17.7% PKM2-positive cells.Importantly,PKM2 expression was correlated with shorter overall survival(P < 0.05) independent of stage only in signet-ring cell cancers.CONCLUSION:PKM2 expression might be an adverse prognostic factor for signet-ring cell carcinomas.Its function and potential as a prognostic marker should be further verified in gastric cancer.

Faecal pyruvate kinase isoenzyme type M2 for colorectal cancer screening:A meta-analysis

AIM:To present a critical discussion of the efficacy of the faecal pyruvate kinase isoenzyme type M2(faecal M2-PK) test for colorectal cancer(CRC) screening based on the currently available studies.METHODS:A literature search in PubMed and Embase was conducted using the following search terms:fecal Tumor M2-PK,faecal Tumour M2-PK,fecal M2-PK,faecal M2-PK,fecal pyruvate kinase,faecal pyruvate kinase,pyruvate kinase stool and M2-PK stool.RESULTS:Stool samples from 704 patients with CRC and from 11 412 healthy subjects have been investigated for faecal M2-PK concentrations in seventeen independent studies.The mean faecal M2-PK sensitivity was 80.3%;the specificity was 95.2%.Four studies compared faecal M2-PK head-to-head with guaiacbased faecal occult blood test(gFOBT).Faecal M2PK demonstrated a sensitivity of 81.1%,whereas the gFOBT detected only 36.9% of the CRCs.Eight independent studies investigated the sensitivity of faecal M2-PK for adenoma(n = 554),with the following sensitivities:adenoma < 1 cm in diameter:25%;adenoma > 1 cm:44%;adenoma of unspecified diameter:51%.In a direct comparison with gFOBT of adenoma > 1 cm in diameter,47% tested positive with the faecal M2-PK test,whereas the gFOBT detected only 27%.CONCLUSION:We recommend faecal M2-PK as a routine test for CRC screening.Faecal M2-PK closes a gap in clinical practice because it detects bleeding and nonbleeding tumors and adenoma with high sensitivity and specificity.

Serum M2-pyruvate kinase: A promising non-invasive biomarker for colorectal cancer mass screening

AIM: To explore the value of serum M2-pyruvate kinase (M2-PK) in colorectal cancer (CRC) mass screening. METHODS: We conducted a molecular epidemiology study in Hangzhou, China, from year 2006 to year 2008. Serum samples were collected from 93 CRC, 41 advanced adenomas, 137 adenomas, 47 non-adenomatous polyps, and 158 normal participants in a community setting. Serum M2-PK and carcinoembryonic antigen (CEA) were measured using Enzyme-linked immunosorbent assay. SPSS 16.0 software was used to perform data analysis. Area under the receiver operating characteristic curve (AUC), sensitivity, and specificities were estimated for serum M2-PK in diagnosis of colorectal lesions and compared with CEA. RESULTS: Average serum M2-PK value among 158 normal people was 2.96 U/mL and not affected by gender (P = 0.47) or age (P = 0.59). Average serum M2-PK (U/mL) was 14.75 among stage III and 13.10 among stage?I?and II CRC patients, about 4 times higher than that among normal people. Average serum M2-PK was 8.58, 6.70, 5.13 and 2.51 U/mL among advanced adenoma, adenomas, non-adenomatous polyps, and inflammatory bowel disease patients, respectively. AUC for serum M2-PK was greater than that for CEA among all colorectal lesions. AUC for serum M2-PK was 0.89 (0.84, 0.94) (95% confidence interval), higher than that for CEA [0.70 (0.62-0.79)] in CRC stage?I?and II, 0.89 (0.84-0.94) vs 0.73 (0.63-0.83) in CRC stage III, 0.81 (0.74-0.86) vs 0.63 (0.53 - 0.73) in advanced adenomas, 0.69 (0.64-0.76) vs 0.54 (0.47-0.60) in adenomas, and 0.69 (0.62-0.78) vs 0.58 (0.48-0.68) in non-adenomatous polyps. The diagnostic sensitivity for all colorectal lesions increased with decrease in the cut-off value of serum M2-PK. The diagnostic sensitivity (%) of serum M2-PK was 100.00 for CRC, 95.12 advanced adenoma, 82.48 adenoma, and 82.98 non-adenomatous polyp. There were no CRC cases missed and 40.51% of unnecessary colonoscopies were avoided when the cut-off value was 2.00 U/mL. CONCLUSION: Serum M2-PK can be used as a primary screening test in CRC mass screening. It may be a promising non-invasive biomarker for CRC early detection.

THE VALUE OF M_2-TYPE PYRUVATE KINASE IMMUNOASSAY IN THE DIAGNOSIS OF HEPATOCARCINOMA

By using Fab'-enzyme labelled immuno absorbent assay (ELISA) with sensitivity of picogram (10-12 g or pg) level, the M-type pyruvate kinase (M-PyK) in plasma was determined in 47 cases of normal healthy adult and 26 cases of hepatocellular carcinoma (HCC) patient. It was found that the upper limits of normal male and female were 1.1 and 1.4 ng/ml (expressed as M2-PyK) respectively. The plasma M-PyK in HCC patients was significant increased to above 5 times of average normal level, the positive rate was about 95%. In 6 cases of subclinical small hepatocarcinoma and 7 cases of HCC patient with normal serum alpha-fetal protein level, the mean plasma M-PyK value was also increased. Whereas the plasma M-PyK level in acute or chronic hepatitis and other benign diseases were normal. After the HCC being resected, the plasma M-PyK returned to normal, but increased again in the cases of recurrent hepatocarcinoma, suggesting that the increased M-PyK in the plasma of HCC patient was criginated from M2-type PyK in HCC tissue. Therefore, plasma M-PyK may become a new micro-level index of hepatocarcinoma.

非小细胞肺癌组织HK2、PKM2蛋白表达与术后复发的临床关系分析

目的探讨非小细胞肺癌(NSCLC)组织己糖激酶2(HK2)、丙酮酸激酶M2型(PKM2)蛋白表达情况及其与术后复发的临床关系。方法回顾性分析在本院行手术治疗的165例NSCLC患者的临床资料。采用免疫组化法检测NSCLC组织与癌旁组织标本HK2、PKM2蛋白表达情况。术后均随访24个月,比较NSCLC组织HK2、PKM2蛋白阳性表达患者与阴性表达患者术后复发情况,并采用Cox回归模型分析法分析NSCLC组织中HK2、PKM2蛋白表达与NSCLC患者术后复发的关系。结果NSCLC组织中HK2、PKM2蛋白阳性表达率均高于癌旁组织(P<0.05)。术后随访24个月,患者复发率为41.21%(68/165);NSCLC组织HK2、PKM2蛋白阳性表达患者术后复发率高于阴性表达患者(P<0.05)。Cox回归模型分析显示,中/低分化、临床分期Ⅲ期、淋巴结转移、术后化疗周期≤4个周期、NSCLC组织中HK2及PKM2蛋白阳性表达均是NSCLC患者术后复发的独立危险因素(HR=3.615、4.909、6.443、4.166、3.904、3.773,P<0.05)。结论HK2、PKM2蛋白在NSCLC组织中均呈阳性表达,且与患者术后短期复发有一定的相关性,其阳性表达可能会增加NSCLC患者术后复发的风险。

Celastrol mitigates inflammation in sepsis by inhibiting the PKM2-dependent Warburg effect

Background: Sepsis involves life-threatening organ dysfunction and is caused by a dysregulated host response to infection. No specific therapies against sepsis have been reported. Celastrol(Cel) is a natural anti-inflammatory compound that shows potential against systemic inflammatory diseases. This study aimed to investigate the pharmacological activity and molecular mechanism of Cel in models of endotoxemia and sepsis.Methods: We evaluated the anti-inflammatory efficacy of Cel against endotoxemia and sepsis in mice and macrophage cultures treated with lipopolysaccharide(LPS). We screened for potential protein targets of Cel using activity-based protein profiling(ABPP). Potential targets were validated using biophysical methods such as cellular thermal shift assays(CETSA) and surface plasmon resonance(SPR). Residues involved in Cel binding to target proteins were identified through point mutagenesis, and the functional effects of such binding were explored through gene knockdown.Results: Cel protected mice from lethal endotoxemia and improved their survival with sepsis, and it significantly decreased the levels of pro-inflammatory cytokines in mice and macrophages treated with LPS(P <0.05). Cel bound to Cys424 of pyruvate kinase M2(PKM2), inhibiting the enzyme and thereby suppressing aerobic glycolysis(Warburg effect). Cel also bound to Cys106 in high mobility group box 1(HMGB1) protein, reducing the secretion of inflammatory cytokine interleukin(IL)-1β. Cel bound to the Cys residues in lactate dehydrogenase A(LDHA).Conclusions: Cel inhibits inflammation and the Warburg effect in sepsis via targeting PKM2 and HMGB1 protein.

Overexpressed PKM2 promotes macrophage phagocytosis and atherosclerosis

Background:The expression of pyruvate kinase muscle 2(PKM2)is augmented in macrophages of patients with atherosclerotic coronary artery disease.The role of PKM2 in atherosclerosis is to be determined.Methods:Global and myeloid cell-specific PKM2 knock-in mice with ApoE^(-/-)background(ApoE^(-/-),PKM2^(KI/KI)and Lyz2-cre,ApoE^(-/-),and PKM2^(flox/flox))were produced to evaluate the clinical significance of PKM2 in atherosclerosis development.Wild-type and PKM2 knock-in macrophages were isolated to assess the function of PKM2 in macrophage phagocytosis.Atherosclerotic mice were treated with PKM2 inhibitor shikonin(SKN)to evaluate the therapeutic potential of PKM2 suppression in atherosclerosis.Results:Oxidized low-density lipoprotein(oxLDL)upregulated PKM2 in macrophages.PKM2 in return promoted the uptake of oxLDL by macrophages.Overexpressed PKM2 accelerated atherosclerosis in mice.SKN blocked the progress of mouse atherosclerosis.Conclusions:PKM2 accelerates macrophage phagocytosis and atherosclerosis.Targeting PKM2 is a potential therapy for atherosclerosis.

丙酮酸激酶M2型(PKM2)入核机制和核内作用的研究进展

传统观点认为丙酮酸激酶M2型(pyruvate kinase M2,PKM2)通过催化肿瘤细胞糖代谢来促进肿瘤细胞生长。近年来研究发现除了酶催化功能外,PKM2还能通过多种途径进入细胞核,在核内作为蛋白激酶广泛参与转录调控、蛋白修饰等过程。本文将就这方面的研究成果作一综述。

复方斑蝥胶囊通过抑制PKM2/HIF-1α通路抑制三阴性乳腺癌生长的机制研究

目的:探讨复方斑蝥胶囊对三阴性乳腺癌细胞恶性生物学行为的影响及分子机制。方法:取5例临床三阴性乳腺癌患者的癌组织和癌旁组织,Western blot实验检测组织中PKM2和HIF-1α的蛋白表达;检测复方斑蝥胶囊处理后的乳腺癌细胞株MDA-MB-231细胞中PKM2和HIF-1α的蛋白表达;Transwell实验检测复方斑蝥胶囊处理后的MDA-MB-231细胞的侵袭能力;通过皮下注射MDA-MB-231细胞的方式构建裸鼠皮下瘤模型,4周后,测量皮下瘤的质量,免疫组织化学检测细胞核增殖抗原PCNA的蛋白表达。结果:PKM2和HIF-1α在三阴性乳腺癌组织及三阴性乳腺癌细胞株中呈高表达;复方斑蝥胶囊抑制MDA-MB-231细胞中PKM2和HIF-1α的表达;复方斑蝥胶囊抑制MDA-MB-231细胞的侵袭;复方斑蝥胶囊抑制裸鼠皮下瘤的生长及皮下瘤PCNA的蛋白表达。结论:复方斑蝥胶囊抑制三阴性乳腺癌的生长,可能与复方斑蝥胶囊抑制乳腺癌细胞中PKM2/HIF-1α信号通路的激活相关。

mTOR-PKM2信号通路与宫颈鳞癌新辅助动脉化疗疗效的相关性研究

目的：研究雷帕霉素靶蛋白（mTOR）-丙酮酸激酶M2（PKM2）信号通路在宫颈鳞癌新辅助动脉化疗前后的改变及其与化疗敏感性的相关性，以期在化疗前预测宫颈鳞癌对化疗药物的敏感性，使患者得到更加有效的个体化治疗。方法选取2007-2012年因巨块型Ⅰb-Ⅱa期宫颈鳞癌行新辅助动脉化疗和宫颈癌根治术的患者36例，所有患者术前均接受以顺铂为基础的联合化疗，评估化疗的疗效。（1）采用Western blot法，检测宫颈鳞癌组织中mTOR和PKM2蛋白的表达。（2）采用免疫组化SP法，检测化疗前后、化疗有效组和无效组宫颈鳞癌组织中mTOR和PKM2的表达差异。结果（1）化疗1～2个周期后，36例宫颈鳞癌患者中，19例为化疗有效，17例为化疗无效。（2）mTOR和PKM2蛋白在宫颈鳞癌组织中特异性表达。（3）mTOR和PKM2蛋白在化疗后宫颈鳞癌组织中的表达均明显低于化疗前（均P＜0.05）。（4）化疗前宫颈癌组织中mTOR和PKM2蛋白的表达在化疗有效组中均比化疗无效组中高（均P＜0.05）。结论早期巨块型宫颈鳞癌组织中mTOR和PKM2蛋白的表达与新辅助动脉化疗的疗效相关。化疗前宫颈鳞癌组织中mTOR和PKM2蛋白的表达有可能成为宫颈癌新辅助动脉化疗疗效的预测指标。

PKM2和Notch1在结直肠癌中的研究进展

研究表明,M2 型丙酮酸激酶(pyruvate kinase M2,PKM2)和Notch1 在结直肠癌组织中高表达,且与结直肠癌的发生、发展有一定的关系;其表达水平亦与肿瘤的化、放疗效果有关,严重影响患者预后,是目前结直肠癌治疗和研究的关键靶点。PKM2 主要通过调节癌细胞代谢及基因转录,促进癌细胞外泌体分泌,并在某些lncRNAs 的调节下发挥促癌作用,可作为结直肠癌的辅助诊断指标。Notch1 可在miRNAs 以及自噬的调节下发挥促癌作用,且可通过促进上皮间质转化(epithelial-mesenchymal transition,EMT)促进结直肠癌转移。此外,PKM2 和Notch1 在结直肠癌中的作用与Wnt/β-连环蛋白(β-catenin)信号通路有联系,但两者之间是否有相关性,目前尚不明确。本文主要就PKM2 和Notch1 在结直肠癌中的研究进展进行探讨,以期为结直肠癌的靶向治疗研究提供新思路。

人PKM_2基因克隆、表达及纯化的研究

目的:构建人PKM2(M2-type pyruvate kinase)的原核表达质粒,并在大肠杆菌中表达,镍离子柱亲和层析法纯化融合蛋白。方法:用PCR方法从宫颈癌Hela细胞全基因组中扩增出目的基因PKM2,通过克隆载体pET30a(+)构建质粒载体pET30a(+)-PKM2。经双酶切和DNA测序证实正确后,用Ni-NTA亲和层析柱进行纯化。结果:双酶切鉴定所切下的片段大小与理论值相符,测序结果和报道一致。经SDS-PAGE分析,纯化后的蛋白约在58KDa位,条带单一,无杂带出现。结论:成功表达纯化了PKM2融合蛋白,为肿瘤疫苗研制和肿瘤标志物快速诊断的研究奠定基础。

原发性肝癌组织中PKM2、COX2及IAPs的表达及其与放疗敏感性的关系分析

目的探究原发性肝癌患者癌组织中M2型丙酮酸激酶(PKM2)、环氧合酶2(COX2)及凋亡蛋白抑制因子(IAPs)的表达及其与放疗敏感性的关系。方法选取接受三维适形放疗的原发性肝癌患者105例,经肝脏穿刺活检采集肝癌组织,采用免疫组化法检测肝癌组织中PKM2、COX2及IAPs家族[X关联凋亡抑制因子(XIAP)、细胞内凋亡抑制蛋白1(cIAP-1)]蛋白的表达,比较不同放疗效果和敏感性患者癌组织中PKM2、COX2、XIAP及cIAP-1蛋白表达的差异,并分析上述蛋白表达与患者预后的关系。结果105例患者肝癌组织中PKM2、COX2、XIAP及cIAP-1蛋白表达阳性率分别为81.90%、74.28%、85.71%及82.86%;COX2、XIAP蛋白阳性表达者治疗有效率与阴性者比较,差异有统计学意义(P<0.05);放疗敏感患者临床分期、分化程度、肿瘤直径、肝癌组织中PKM2、COX2、XIAP及cIAP-1蛋白表达情况与放疗不敏感者比较,差异有统计学意义(P<0.05);高临床分期、低分化程度、COX2、XIAP阳性表达是患者放疗不敏感的独立危险因素(P<0.05);XIAP阳性表达者复发率和转移率与阴性表达者比较,差异有统计学意义(P<0.05)。结论原发性肝癌患者癌组织中PKM2、COX2、XIAP及cIAP-1阳性率高,其中COX2、XIAP蛋白表达与患者放疗效果、敏感性密切相关,XIAP蛋白表达还与患者复发转移有关。

HIF-1α/ALYREF/PKM2信号轴在膀胱癌糖酵解和肿瘤发生中的作用

背景与目的 丙酮酸激酶肌肉同工酶M2(pyruvate kinase muscle isozyme M2,PKM2)是糖酵解的限速酶,参与肿瘤的代谢和生长。PKM2在肿瘤中的调控网络复杂,在膀胱癌中尚未得到充分研究。PKM2 mRNA的5-甲基胞嘧啶(5-methylcytidine,m5C)修饰可能参与了膀胱癌的发病过程,机理有待深入研究。本文旨在探讨PKM2在膀胱癌中的生物学功能及其调控机制。方法 用Western blotting、qRT-PCR和免疫组织化学方法检测PKM2和Aly/REF输出因子(Aly/REF export factor,ALYREF)的表达水平。通过一系列体内实验和体外试验,研究膀胱癌细胞的生物学过程。通过RNA免疫沉淀、RNA测序和双荧光素酶报告分析,探讨PKM2在膀胱癌中的调控机制。结果 在膀胱癌中,我们首次证明了ALYREF稳定了PKM2的mRNA,并与其3’-非翻译区的m5C位点结合。ALYREF过表达通过PKM2介导的糖酵解促进膀胱癌细胞增殖。此外,PKM2和ALYREF高表达与膀胱癌患者生存不佳相关。最后,我们发现缺氧诱导因子1α(hypoxia-inducible factor-1 alpla,HIF-1α)除了直接激活转录,还通过激活ALYREF间接上调PKM2的表达。结论 HIF-1α/ALYREF/PKM2轴上PKM2 mRNA的m5C修饰可能促进了膀胱癌的葡萄糖代谢,为膀胱癌的治疗提供了新的靶点。

肺腺癌组织中基质窖蛋白-1和LDH-B、PKM2的表达及其意义

目的探讨基质窖蛋白1(Cav-1)、乳酸脱氢酶B(LDH-B)和丙酮酸激酶2(PKM2)在人肺腺癌(PAC)组织中的表达并分析3者的相关性及其临床意义。方法采用量子点免疫荧光组织化学(QDs-IHC)技术检测68例PAC组织和16例非癌性肺组织中基质Cav-1、LDH-B和PKM2的表达情况。结果基质Cav-1在PAC组织的阳性率为58.8%,与非癌变肺组织的阳性率100%相比,差异有统计学意义(P<0.05)。肺腺癌组织中LDH-B和PKM2的阳性率分别为76.5%、70.6%,均高于非癌性肺组织(均P<0.05)。PAC中、低分化组PKM2的阳性率均高于高分化组(均P<0.05)。结论基质Cav-1缺失,LDH-B、PKM2的高表达可能促进PAC的恶性进展。

HK2、PFK1和PKM2在子宫内膜异位症中的表达

目的:探索己糖激酶2(HK2)、磷酸果糖激酶1(PFK1)和丙酮酸激酶M2(PKM2)在子宫内膜异位症(EMT)中的表达及意义。方法:收集37例正常子宫内膜组织和34例异位子宫内膜组织,使用ELISA检测组织中LDH活性。同时,利用qRT-PCR技术检测HK2、PFK1和PKM2的mRNA表达;采用Western blot技术测得HK2和PKM2的蛋白表达。结果:异位内膜组织中的LDH活性高于正常内膜组织(P<0.05);与正常子宫内膜组织相比,异位子宫内膜组织中HK2和PKM2的mRNA及蛋白水平均升高(P<0.05)。结论:子宫内膜异位症中存在代谢异常,其中HK2和PKM2表达升高,可能与内异症的发生相关。