A review of platinum complex biochemistry suggests a rationale for combined platinum-radiotherapy

A review of the biochemistry of platinum coordination complexes represented by the parent complex cis-dichlorodiammineplatinum II, (cis-DDP), indicates that this family of chemotherapeutic agents binds to DNA affording the potential for interactions with other therapeutic modalities. Results of relatively recent studies in bacteria, mammalian cell cultures and in animal tumor systems suggest that these platinum complexes interact with irradiation, thereby producing cell kill that may be greater than additive. A rationale is provided for the combination of cis-DDP and other platinum complexes with radiotherapy in the treatment of cancer.     

Expression of ATP7B in human gastric cardiac carcinomas in comparison with distal gastric carcinomas

~~Expression of ATP7B in human gastric cardiac carcinomas in comparison with distal gastric carcinomas~~1 Wang LD, Zheng S, Zheng ZY, Casson AG. Primary adenocarcinomas of lower esophagus, esophagogastric junction and gastric cardia: in special refere…     

XRCC1基因多态性与晚期非小细胞肺癌铂类化疗敏感性的研究

目的：研究XRCC1基因多态性与非小细胞肺癌（NSCLC）患者对铂类为基础的联合化疗的敏感性。方法：收集我院NSCLC患者54例,提取外周白细胞DNA,采用多重PCR对XRCC1194,399两个多态性住点同时扩增,对扩增产物进行纯化后直接测序,判定基因分型。结果：携带XRCC1399Arg／Arg的化疗有效率是Gln／Gln的2．5倍（P=0．035。95％CI=0．892-7．094）。携带一个Gln等位基因的化疗失败风险是携带Arg／Arg的1．7倍（P=0．044,95％CI=1．012～2．720）。未发现XRCC1194不同基因型对铂类化疗敏感性有差异。结论：XRCC1399Gln／Arg基因多态性与晚期NSCLC接受铂类为基础的化疗敏感性相关。     

晚期非小细胞肺癌患者铂类药物敏感性与ERCC1和BAG-1基因多态性的关联性研究

目的探讨晚期非小细胞肺癌患者铂类药物敏感性与ERCC1和BAG-1基因多态性间的关联性。方法随机选取接受铂类药物化疗的NSCLC患者100例,采用PCR—RFLP法和Logistic回归模型检测和分析患者ERCC1和BAG～1位点多态性及其与铂类药物敏感性的关联性。结果ERCC1位点基因型频率分为CC、TF和CT型分别占61．0％、7．0％和32．0％;CC型患者对铂类药物敏感性是T基因携带者的2．523倍,达到显著（P〈0．05）;BAG-1位点基因型频率CC、TT和CT型分别占77．0％、2．0％和21．0％,CC型患者对铂类药物敏感性是T基因携带者的2．738倍,达到显著（P〈0．05）。结论ERCC1和BAG—1基因多态性可能与NSCLC患者对铂类药物敏感性存在关联性,CC基因型可能对铂类药物较为敏感。     

奥沙利铂对肝癌细胞HepG2细胞周期的影响

目的:探讨奥沙利铂(Oxaliplatin,L-OHP)对人肝癌细胞株HepG2周期的影响及其相关机制,为其应用于原发性肝细胞癌临床治疗提供理论依据。方法:MTT方法检测L-OHP对肝癌细胞HepG2生长的抑制作用;流式细胞术(FCM)检测L-OHP诱导HepG2细胞周期阻滞的作用;RTPCR和Western blot方法观察L-OHP对细胞周期调节因子CyclinD1、CDK2、CDK4及p16、p21、p53表达的影响。结果:MTT结果显示L-OHP对HepG2细胞增殖抑制率随药物浓度增加及作用时间延长有升高趋势,呈时间剂量依赖性。L-OHP能够诱导HepG2细胞周期阻滞于S期,并可下调CDK4和CyclinD1蛋白的表达,上调p21,p53蛋白的表达,CDK2和p16表达无明显变化。结论:L-OHP可能通过影响CDK4、CyclinD1及p21的活性使HepG2细胞阻滞在S期,从而抑制肝癌细胞HepG2的增殖。     

Estimated Glomerular Filtration Rate Is an Easy Predictor of Venous Thromboembolism in Cancer Patients Undergoing Platinum‐Based Chemotherapy

Background.

Reduced estimated glomerular filtration rate (eGFR) has been associated with increased venous thromboembolism (VTE) risk in the general population. VTE incidence significantly increases in cancer patients, especially those undergoing chemotherapy. Despite the evidence that a substantial number of cancer patients have unrecognized renal impairment, as indicated by reduced eGFR in the presence of serum creatinine levels within the reference value, chemotherapy dosage is routinely adjusted for serum creatinine values. Among chemotherapies, platinum-based regimens are associated with the highest rates of VTE. A cohort study was designed to assess the value of pretreatment eGFR in the risk prediction of a first VTE episode in cancer outpatients without previous history of VTE who were scheduled for platinum-based chemotherapy.

Methods.

Serum creatinine and eGFR were evaluated before the start of standard platinum-based chemotherapy in a cohort of 322 consecutive patients with primary or relapsing/recurrent solid cancers, representative of a general practice population.

Results.

Patients who experienced a first VTE episode in the course of chemotherapy had lower mean eGFR values compared with patients who remained VTE free. Multivariate Cox analysis demonstrated that eGFR had an independent value for risk prediction of a first VTE episode during treatment, with a 3.15 hazard ratio. Indeed, 14% of patients with reduced eGFR had VTE over 1-year follow-up compared with 6% of patients with normal eGFR values.

Conclusion.

The results suggest that reductions in eGFR, even in the presence of normal serum creatinine, are associated with an increased VTE risk in cancer outpatients undergoing platinum-based chemotherapy regimens. Determining eGFR before chemotherapy could represent a simple predictor of VTE, at no additional cost to health care systems.     

Micro coulter counters with platinum black electroplated electrodes for human blood cell sensing

We demonstrated a novel micro Coulter counter featuring platinum-black electrodes for human blood cell counting application. Two designs of micro Coulter counter were fabricated using two distinct technologies: integrated parylene and soft lithography. Platinum-black enhanced detection in the intermediate frequency range (∼100 Hz to 7 MHz), which is the operation frequency suitable for sensing the cells flowing by the electrodes. A detailed theoretical modeling of the sensing mechanism has been performed for the design of the electrodes, and electrical impedance spectra measurements confirmed the theoretical model. The surface morphology and roughness of the platinum black electroplated surface were characterized by SEM and AFM measurements. Polystyrene beads of various sizes were initially used to validate the operation of the devices, and using excitation frequency of 10 kHz, the signal magnitude was found to be correlated with the volume of the individual bead. Human blood cell sensing was successfully demonstrated with diluted whole blood and leukocyte rich plasma under the same excitation frequency. The histogram of impedance magnitude of the cells matched well with volume distributions of erythrocytes and leukocytes measured by conventional counting techniques. Micro Coulter counters have the advantages of small foot-print, low sample volume, and reduced cost of operation. Further development of the devices can lead to the development of a highly-sensitive and high-throughput handheld blood counting system for point-of-care applications.     

Effects of a potent antioxidant, platinum nanoparticle, on the lifespan of Caenorhabditis elegans

We have shown that platinum nanoparticles (nano-Pt) are a superoxide dismutase (SOD)/catalase mimetic. Various data have shown extension of the Caenorhabditis elegans lifespan by antioxidant treatment. The present study was designed to elucidate the survival benefit conferred by nano-Pt, as compared to the well-known SOD/catalase mimetic EUK-8. At 0.5mM, nano-Pt significantly extended the lifespan of wild-type N2 nematodes and at 0.25 and 0.5mM, nano-Pt recovered the shortened lifespan of the mev-1(kn1) mutant, which is due to excessive oxidative stress. In both instances, EUK-8 at 0.05, 0.5, and 5mM did not extend nematode lifespan. Even when 0.4M paraquat was loaded exogenously, nano-Pt (0.1 and 0.5mM) and EUK-8 (0.5 and 5mM) were effective in rescuing worms. Moreover, 0.5mM nano-Pt significantly reduced the accumulation of lipofuscin and ROS induced by paraquat. We measured the in vitro dose-dependent quenching of O(2)(-) and H(2)O(2), indicating that nano-Pt is a more potent SOD/catalase mimetic than EUK-8. Nano-Pt prolonged the worm lifespan, regardless of thermotolerance or dietary restriction. Taken together, nano-Pt has interesting anti-ageing properties.     

Synthesis, antiproliferative activity and DNA binding study of mixed ammine/cyclohexylamine platinum(II) complexes with 1-(substituted benzyl) azetidine-3, 3-dicarboxylates

A novel series of ammine/cyclohexylamine platinum(II) complexes with 1-(substituted benzyl) azetidine-3, 3-dicarboxylates as leaving groups have been synthesized and characterized. All complexes were characterized by elemental analysis, IR, ¹H NMR, and ESI-MS spectra. The in vitro antiproliferative activities of the platinum-based compounds have been investigated against several human cancer cell lines, indicating that complexes 1 and 11 showed comparable cytotoxicity to those of cisplatin and oxaliplatin against four cell lines, superior to that of carboplatin. The results of drug safety evaluation (acute toxicity study) showed that complex 11 was much less toxic than cisplatin and oxaliplatin. Flow cytometry and agarose gel electrophoresis studies revealed that both complexes 1 and 11 induced apoptosis of tumor cells and demonstrated the binding affinity of complexes with pET22b plasmid DNA.     

超分子铂类药物对消化道肿瘤作用的观察

目的:对超分子铂类药物对消化道肿瘤的作用进行观察。方法:选用西茜铂和卡铂对半数抑制浓度(IC50)人胚肺成纤维细胞胰腺癌、肝癌、结肠癌和胃癌6株消化系癌细胞进行体外试验。结果:体外试验6株肿瘤细胞的IC50值CCP明显低于卡铂,约为卡铂的1/3～1/2,但人胚肺成纤维细胞的IC50值CCP和卡铂均在240 ml/L以上。结论:超分子铂类药物对消化道肿瘤有明显的抑制作用,高于卡铂的临床疗效。