Wechsel H W, Petri E, Bichler K H, Feil G
Department of Urology, Eberhard-Karls-University, Tuebingen, Germany.
Anticancer Res. 1999 Jul-Aug;19(4A):2583-90.
The evaluate a potential tumor marker for RCC. Tumor formation is generally linked to an expansion of glycolytic phosphometabolite pools and aerobic glycolyticflux rates. To achieve this, tumor cells generally overexpress a special glycolytic isoenzyme, termed pyruvate kinase type M2. To establish the expansion of phosphometabolite pools pyruvate kinase switches between a tetrameric form with high phosphoenol-pyruvate (PEP) affinity and a dimeric form with a lower PEP affinity. The dimeric form is predominant in all tumors that have been investigated and has been termed TuM2Pk.
We studied: a) the expression of TuM2Pk in RCC by immunohistochemistry using a monoclonal antibody recognizing only the mono- or dimeric form of pyruvate kinase, b) the stability of TuM2Pk in serum by measuring TuM2Pk in 3 patients at different times after taking blood with a two-site immunometric assay, c) the a circadiane rhythm of TuM2Pk in blood by measuring levels every 4 hours in 5 patients, d) TuM2Pk- expression in serum (see 2.) in 5 patients by taking blood from tumor-side vena renalis compared to peripherally blood, e) TuM2Pk (see point 2.) in 40 RCC-patients comparing the results with 39 healthy persons and clinical data of RCC, f) the influence of wound healing to TuM2Pk by measuring serum-levels during a period of more than 12 weeks in 6 patients, g) the individual follow up of 4 patients with RCC stage Robson III for more than 2 years. Comparing TuM2Pk-levels to findings of staging by computed tomography.
The isoenzyme TuM2Pk could be demonstrated in RCC and their metastases by immunohistochemistry with a monoclonal antibody specific for pyruvate kinase type M2. In normal kidney cells pyruvate kinase type M2 is not detectable. The stability of TuM2Pk was studied in the serum within 30 minutes. No circadian rhythm was found. Most serum TuM2Pk comes from tumor. Serum evaluation in 39 healthy persons was used to determine normal values, with an upper concentration of 28 U/ml of TuM2Pk (95% percentile of normal healthy persons). Serum evaluation in 40 RCC showed a significant difference to healthy persons and a positive correlation with Robson stage and grading No correlation of TuM2Pk was found with histopathological cell type of tumor diameter. After radical nephrectomy normalization of TuM2Pk level was found within 11 weeks in all localized RCC. Continuously elevated serum levels were seen in metastatic RCC. Individual follow-up seems to be possible.
Initial discrimination is not possible between localized and metastasized RCC using TuM2PK; however, it is possible to differentiate between benign and malignant renal processes; the specificity under these circumstances is 75%. After successful surgery of localized RCC, an elevated TuM2Pk will be normalized within 11 weeks, and will be remain elevated or will increase again in case of RCC-relapse or metastasis. Thus TuM2Pk would appear to be a useful marker for RCC detection and follow-up.
评估一种用于肾细胞癌（RCC）的潜在肿瘤标志物。肿瘤形成通常与糖酵解磷酸代谢物池的扩大和有氧糖酵解通量率有关。为此，肿瘤细胞通常会过度表达一种特殊的糖酵解同工酶，即M2型丙酮酸激酶。为了实现磷酸代谢物池的扩大，丙酮酸激酶会在具有高磷酸烯醇丙酮酸（PEP）亲和力的四聚体形式和具有较低PEP亲和力的二聚体形式之间转换。二聚体形式在所有已研究的肿瘤中占主导地位，被称为TuM2Pk。
我们进行了以下研究：a）通过免疫组织化学，使用仅识别丙酮酸激酶单体或二聚体形式的单克隆抗体，研究TuM2Pk在RCC中的表达；b）通过双位点免疫测定法，在3名患者采血后的不同时间测量TuM2Pk，研究其在血清中的稳定性；c）通过每4小时测量5名患者的水平，研究血液中TuM2Pk的昼夜节律；d）从肿瘤侧肾静脉采血与外周血相比，研究5名患者血清中TuM2Pk的表达（见2.）；e）在40名RCC患者中检测TuM2Pk（见第2点），并将结果与39名健康人及RCC的临床数据进行比较；f）通过在6名患者超过12周的时间内测量血清水平，研究伤口愈合对TuM2Pk的影响；g）对4例Robson III期RCC患者进行超过2年的个体随访。将TuM2Pk水平与计算机断层扫描分期结果进行比较。
通过使用针对M2型丙酮酸激酶的单克隆抗体进行免疫组织化学，可在RCC及其转移灶中检测到同工酶TuM2Pk。在正常肾细胞中未检测到M2型丙酮酸激酶。在30分钟内研究了TuM2Pk在血清中的稳定性。未发现昼夜节律。大多数血清TuM2Pk来自肿瘤。对39名健康人的血清评估用于确定正常值，TuM2Pk的上限浓度为28 U/ml（健康正常人的第95百分位数）。对40名RCC患者的血清评估显示与健康人有显著差异，且与Robson分期和分级呈正相关。未发现TuM2Pk与肿瘤直径的组织病理学细胞类型相关。在所有局限性RCC中，根治性肾切除术后11周内TuM2Pk水平恢复正常。转移性RCC患者血清水平持续升高。似乎可以进行个体随访。
使用TuM2PK无法对局限性和转移性RCC进行初步区分；然而，有可能区分良性和恶性肾脏病变；在这种情况下特异性为75%。局限性RCC成功手术后，升高的TuM2Pk将在11周内恢复正常，而在RCC复发或转移时将保持升高或再次升高。因此，TuM2Pk似乎是RCC检测和随访的有用标志物。
