Recombinant human erythropoietin in comparison to amifostine against cisplatin-induced peripheral sensorial neurotoxicity in rats

Cisplatin (CDDP) can cause dose-limiting neurotoxicity. We have investigated the role of recombinant human erythropoietin (rHuEPO) in the prevention of CDDP-induced peripheral sensory neurotoxicity. Wistar-albino rats were randomly assigned to three groups: Group A received only CDDP, Group B received CDDP plus amifostine and Group C received CDDP plus rHuEPO. At 7 weeks, Group C was divided into two subgroups; C1 received maintenance rHuEPO for 3 additional weeks, C2 received no treatment. Somatosensory evoked potentials (SEPs) were carried out at baseline, and at 7 and 10 weeks. At baseline, all groups were comparable in terms of area, amplitude and spinal potential normalized velocity (SPNV). The comparison of area, amplitude and SPNV data as well as their percent changes between 7 and 10 weeks showed no difference between Groups A, B, C1 and C2. We conclude that at the given dose and schedule, rHuEPO appears to have neuroprotective activity; however, maintenance rHuEPO treatment does not seem to provide further benefit.     

Early predictors of peripheral neurotoxicity in cisplatin and paclitaxel combination chemotherapy.

BACKGROUND: We investigated the possible use of clinical signs of chemotherapy-induced peripheral neurotoxicity (CIPN) or of nerve growth factor (NGF) circulating levels to predict the final outcome of CIPN. PATIENTS AND METHODS: Sixty-two women affected by locally advanced squamous cervical carcinoma treated with TP (paclitaxel 175 mg/m2 over a 3 h infusion plus cisplatin 75 mg/m2) or TIP (TP plus ifosphamide 5 mg/m2) were examined and scored according to the Total Neuropathy Score (TNS), before and during chemotherapy. RESULTS: A correlation with the final severity of CIPN was observed with vibration perception and deep tendon reflex evaluation, while pin sensibility, strength, and autonomic symptoms and signs were not informative. A highly significant correlation existed between the decrease in circulating levels of NGF and the severity of CIPN (r = -0.579; P < 0.001; 95% confidence limits -0.702 to -0.423). However, circulating levels of NGF were not effective as predictors of the final neurological outcome of each patient. CONCLUSION: Our study indicates that a precise clinical evaluation of the peripheral nervous system of patients treated with platinum and taxane combination polychemotherapy not only gives reliable information regarding the course of CIPN, but also can be used to predict the final neurological outcome of the treatment.     

Chemotherapy-induced peripheral neurotoxicity in the era of pharmacogenomics

Development of advanced and high-throughput methods to study variability in human genes means we can now use pharmacogenomic analysis not only to predict response to treatment but also to assess the toxic action of drugs on normal cells (so-called toxicogenomics). This technological progress could enable us to identify individuals at high and low risk for a given side-effect. Pharmacogenomics could be very useful for stratification of cancer patients at risk of developing chemotherapy-induced peripheral neurotoxicity, one of the most severe and potentially permanent non-haematological side-effects of modern chemotherapeutic agents. However, study data reported so far are inconsistent, which suggests that methodological improvement is needed in clinical trials to obtain reliable results in this clinically relevant area.     

Cisplatin-induced peripheral neurotoxicity is dependent on total-dose intensity and single-dose intensity.

The authors prospectively evaluated the effects of three different schedules of cisplatin (DDP) administration in 60 patients with advanced epithelial ovarian cancer. The individual total dose of DDP was 450 mg/m2 in all three groups, and the anti-cancer response at the end of treatment was similar for the different regimens. The clinical and neurophysiologic results confirmed that axonal sensory neuropathy occurred after the standard administration of DDP (75 mg/m2 in 3-week cycles) and probably not only the peripheral, but also the central sensory pathway, was involved. Although the total dose of the drug was identical, the two less conventional schedules were less neurotoxic. These results suggest that not only the total-dose intensity, but also the single-dose intensity are relevant in the onset of DDP-induced sensory neuropathy; therefore, the use of less neurotoxic schedules may prevent or reduce sensory nerve damage.     

The in vivo antimelanoma effect of 4-S-cysteaminylphenol and its n-acetyl derivative

Phenolic melanin precursors can be utilized for the development of anti-melanoma agents. The sulphur homologue of tyrosine, 4-S-cysteinylphenol (CP) and its decarboxylation product, 4-S-cysteaminylphenol (CAP) were shown to be substrates of melanoma tyrosinase, forming melanin-like pigment. Both, but in particular the 4-S-CAP, exhibited a significant in vivo depigmenting effect. Here, we report on the in vivo anti-melanoma effect of 4-S-CP, and 4-S-CAP and its N-acetyl derivative. In a previous in vitro study, it was shown that 4-S-CP and 4-S-CAP required a catalytic amount of dopa for optimal mammalian tyrosinase activity. To enhance the potential anti-melanoma effect of these two compounds. L-dopa and a decarboxylase inhibitor (carbidopa) were given concomitantly. We found that 4-S-CAP showed a significant growth inhibition of B16 melanoma inoculated s.c. into C57BL/6J mice. The anti-melanoma effect was increased significantly by combination of L-dopa and carbidopa. In addition, we tested the in vivo anti-melanoma effect of an N-acetyl derivative of 4-S-CAP (N-Ac-4-S-CAP). We found that N-Ac-4-S-CAP was the tyrosinase substrate and potent inhibitor of melanoma growth. N-acetyl 4-S-CAP showed a marked increase in water solubility. We suggest that N-Ac-4-S-CAP may prove to be a valuable model for the development of anti-melanoma agent using a metabolic pathway of melanin synthesis.     

Protective effect of cholesterol on Friend leukemic cells against photosensitization by hematoporphyrin derivative

The cytotoxic effects of hematoporphyrin derivative (HPD) on Friend erythroleukemic cells were studied. Upon binding of the porphyrin to the cells, the fluorescence spectra was shifted from 613 to 633 nm regarding the main band and from 676 to 667 nm concerning the secondary band. The kinetics of HPD binding was then determined. Maximum binding already occurred at 60 s after exposure of the cells to HPD. It could be demonstrated that the effect of the photoactivated HPD on cell viability was drug, dose, and light fluorescence dependent. Cellular protein synthesis and Friend virus complex release from the cells were equally inhibited by the photodynamic sensitization of the drug, indicating no specific effect on virus maturation. Since cholesterol affects the fluidity of cell membranes, it was important to study the effect of cholesterol enrichment on the photodynamic sensitization by HPD. It was found that, while a 50% reduction in protein synthesis was monitored following treatment with 20 micrograms of HPD per ml and illumination by a 6-milliwatt white light for 60 s, no inhibition was observed following preenrichment of the cells with 0.5, 1, or 2% of cholesterol hemisuccinate. The same trend of cholesterol protection was demonstrated with longer illumination periods up to 10 min. The protective effect of cholesterol hemisuccinate was also seen using scanning electron microscopy. It is thus concluded that the cholesterol hemisuccinate content of Friend erythroleukemic cell membranes is an important factor in regulating the cytotoxicity of photoactivated HPD.     

Cisplatin neurotoxicity in the treatment of metastatic germ cell tumour: time course and prognosis

In order to ascertain the incidence and prognosis of cisplatin-induced neurotoxicity in testis cancer patients undergoing combination chemotherapy, 29 patients with metastatic disease were studied prospectively. Assessments included enquiry into neurological symptoms, measurement of sural nerve sensory action potential and conduction velocity, and vibration threshold in the left big toe. At the end of chemotherapy (3 to 4 cycles) only 3 out of 26 (11%) patients had paraesthesiae, but 3 months later the proportion rose to 65%. Resolution occurred in the majority over the ensuing 12 months so that only 17% had persistent symptoms. None of the 11 patients treated with 3 cycles of chemotherapy had persisting symptoms. Vibration thresholds showed a significant deterioration during chemotherapy (P = 0.032), further deterioration in the 3 months following chemotherapy (P = 0.009) and significant improvement between 3 and 12 months after chemotherapy (P = 0.038). Sural nerve sensory action potentials and conduction velocities were unhelpful.     

Enhanced radiosensitivity in experimental tumours following erythropoietin treatment of chemotherapy-induced anaemia.

The radiosensitivity of solid tumours in anaemic rats treated with recombinant human erythropoietin (rhEPO, epoetin beta) was studied. Anaemia was induced by a single dose of carboplatin (45 mg kg(-1) i.v.), resulting in a reduction in the haemoglobin concentration by 30%. In a second group, the development of anaemia was prevented by rhEPO (1000 IU kg(-1)) administered s.c. three times per week starting 6 days before the carboplatin application. Three days after carboplatin treatment, DS-sarcomas were implanted subcutaneously onto the hind foot dorsum. Neither carboplatin nor rhEPO treatment influenced tumour growth rate. Five days after implantation, tumours were irradiated with a single non-curative dose (10 Gy), resulting in a growth delay with a subsequent regrowth of the tumours. In the rhEPO-treated group, the growth delay lasted significantly longer (9.5 days vs. 4.5 days) and the regrowth was slower (6.0 days vs. 4.1 days) compared with the anaemic group. These data suggest that the correction of chemotherapy-induced anaemia by rhEPO (epoetin beta) treatment increases tumour radiosensitivity, presumably as a result of an improved oxygen supply to tumour tissue.     

Stereoselective peripheral sensory neurotoxicity of diaminocyclohexane platinum enantiomers related to ormaplatin and oxaliplatin.

The diaminocyclohexane platinum (Pt(DACH)) derivatives ormaplatin and oxaliplatin have caused severe and dose-limiting peripheral sensory neurotoxicity in a clinical trial. We hypothesized that this toxicity could vary in relation to the biotransformation and stereochemistry of these Pt(DACH) derivatives. We prepared pure R,R and S,S enantiomers of ormaplatin (Pt(DACH)Cl4), oxaliplatin (Pt(DACH)oxalato) and their metabolites (Pt(DACH)Cl2 and Pt(DACH)methionine) and assessed their peripheral sensory neurotoxicity and tissue distribution in the rat and in vitro anti-tumour activity in human ovarian carcinoma cell lines. The R,R enantiomers of Pt(DACH)Cl4, Pt(DACH)oxalato and Pt(DACH)Cl2, induced peripheral sensory neurotoxicity at significantly lower cumulative doses (18 +/- 5.7 vs 32 +/- 2.3 micromol kg(-1); P < 0.01) and at earlier times (4 +/- 1 vs 6.7 +/- 0.6 weeks; P = 0.016) during repeat-dose treatment than the S,S enantiomers. Pt(DACH)methionine enantiomers showed no biological activity. There was no difference between Pt(DACH) enantiomers in the platinum concentration in sciatic nerve, dorsal root ganglia, spinal cord, brain or blood at the end of each experiment. Three human ovarian carcinoma cell lines (41 M, 41 McisR and SKOV-3) showed no (or inconsistent) chiral discrimination in their sensitivity to Pt(DACH) enantiomers, whereas two cell lines (CH-1 and CH-1cisR) showed modest enantiomeric selectivity favouring the R,R isomer (more active). In conclusion, Pt(DACH) derivatives exhibit enantiomeric-selective peripheral sensory neurotoxicity during repeated dosing in rats favouring S,S isomers (less neurotoxic). They exhibited less chiral discrimination in their accumulation within peripheral nerves and in vitro anti-tumour activity.     

氨磷汀对顺铂肾毒性损伤的保护作用及其机制的研究

目的 观察顺铂的肾毒性损伤部位、形式与肾功能检查结果的相关性,以了解细胞凋亡的发生机制和氨磷汀的保护机制是否与肾组织Fas和FasL表达改变有关。方法 随机将大鼠分成3组,即对照组（生理盐水）、顺铂组（6mg／kg）和氨磷汀组（顺铂6mg／kg＋氨磷汀200mg／kg）,取其血清标本和肾组织,分别做血清BUN、Cr检测和肾组织病理学检查,并用原位缺口末端标记法（TUNEL）做肾组织凋亡细胞检测、Fas和FasL免疫组化染色,再用图像分析软件对其做阳性细胞计数和染色总灰度值测定。结果 顺铂组动物血清BUN、Cr值均明显高于对照组和氨磷汀保护组,3d时,差异已有统计学意义（P〈0．05）;5d时,两者差异分别为P〈0．01和P〈0．05;10d时,恢复正常。顺铂组肾小管上皮细胞坏死和凋亡均很严重,其凋亡细胞计数明显高于对照组和氨磷汀组（P值均〈0．01）,肾组织Fas和FasL表达的总灰度值,明显高于对照组和氨磷汀组（P值均〈0．01）。结论 氨磷汀对顺铂的肾毒性损伤有保护作用,其机制可能与抑制肾组织Fas和FasL的表达有关。     

Photodynamic effect in an experimental bladder tumor treated with intratumor injection of hematoporphyrin derivative

Photodynamic therapy (PDT) is an experimental treatment modality for malignant tumors. It is based on the principle that a photosensitizer, such as hematoporphyrin derivative (HPD), is retained in higher concentrations in tumors than in surrounding nonmalignant tissues and that photoactivation of the sensitizer can be used to evoke tumor destruction. However, retention of the systemic injection of HPD is not limited to malignant tissues. This lack of specific tumor localization thus reduces the therapeutic ratio of the treatment and causes skin photosensitivity and possible systemic toxicity. Injection of HPD directly into the tumor, on the other hand, has been shown to yield higher levels of the drug in the tumor and lower levels in normal tissues, in comparison with systemic administration. In this study, we examined the photodynamic effect on s.c. implanted mouse bladder tumors subjected to intratumor (i.t.) and i.p. HPD injections. Tumor cell killing, measured by cell survival, was observed in both the it. and i.p. groups and was dependent on fluence and HPD dosage. However, no significant enhancement of cell killing was observed in the i.t. injected tumors, despite the higher porphyrin levels in these tumors. Histological examination of the effect of PDT on the blood vessels indicated that while cell death accompanied severe hemorrhage in the i.p. injected tumors, in the i.t. tumors there was much less hemorrhage and intact blood vessels remained. This observation suggests that with i.t. administration, direct photodynamic action may play a significant role in the tumor cell killing, in contrast to systemic administration, in which destruction of the blood vessels is believed to be the main cause of tumor destruction.     

Protective Role of Bilberry Extract Against Cisplatin Induced Ototoxicity in Rats

To investigate the potential preventive effect of bilberry extract in cisplatin-induced ototoxicity. Thirty-five 3–3.5-month healthy adult female Sprague–Dawley rats were randomly divided into three groups and treated as follows: Both, group 1 (n = 10) and group 2 (n = 15) subjects received a single dose of 12 mg/kg cisplatin intraperitoneally; while in group 2, bilberry extract was also administered via gavage feeding for 15 days. Group 3 (n = 10), received no cisplatin or bilberry extract. Baseline distortion product otoacoustic emissions testing were performed in all subjects prior to administration of any medication. The test was repeated at 15th day following administration of any medication. The distortion product otoacoustic emissions were evaluated at 1.5, 2, 3, 4, 5, 6, 7, 8, 10 and 12 kHz. Histopathological changes in the cochlea of rats were observed by light microscopy. There was no statistically significant difference in apical turn between three groups but there was a statistically significant difference in basal and mid turn external ciliated cells number. Stria vascularis changes were statistically significant between three groups. The median score for stria vascularis injury and spiral ganglion cells changes were significantly greater in group 1 than in group 2. The initial distortion product otoacoustic emissions measurement results gave similar statistically insignificant values in the three groups (p > 0.05). In contrast to initial measurements statistically significant differences were recorded between day 0 and 15 otoacoustic thresholds (p < 0.05). Bilberry extract group had a significantly higher DP-gram except for 1.5 and 2 kHz frequencies when compared to cisplatin group. The analyses of the results revealed statistically significant differences between two groups (p < 0.05), suggesting that bilberry extract had shown a protective effect against cisplatin ototoxicity. The results of our study revealed that treatment with bilberry extract affords significant protection to the cochlea from cisplatin toxicity and thus, oral experimental dose of bilberry extract administration may have a protective effect against cisplatin ototoxicity in rats.     

Expression of erythropoietin and its receptor in neuroblastomas

BACKGROUND: Children with high-risk neuroblastomas (NB) potentially may benefit from treatment with recombinant human erythropoietin (Epo). Epo is a stimulator of erythropoiesis, acting through its receptor (EpoR). The objective of the current study was to evaluate expression levels of Epo and EpoR in NB and in normal tissues and their effects on the proliferation of tumor cells. METHODS: A tissue microarray study was performed with 101 primary tumors, 39 paired metastases, 56 paired control tissues, and 6 human NB cell lines. Immunohistochemical staining was performed using antibodies against Epo and EpoR. Immunostaining intensity was evaluated by using a semiquantitative score based on the percentage of positive cells. An in vitro analysis of cell proliferation and cell cycle in the presence of recombinant Epo was performed in the 6 cell lines. RESULTS: The expression of EpoR was found to be significantly higher in tumors than in paired control tissues (P < .0001) compared with the expression of Epo (P = .06), and the expression of EpoR was significantly higher in lymph node metastases than in paired primary tumors (P = .02) compared with Epo (P = .99). Survival analysis demonstrated that the patients who had tumors with the highest expression of EpoR had a significantly better overall survival (P = .03). In the in vitro study, recombinant Epo did not modify proliferation and cell cycle in the cell lines regardless of the EpoR expression level. CONCLUSIONS: Epo and EpoR were expressed in NB but did not modify tumor cell proliferation. The results of the current study suggested that Epo may be used safely for supportive care in children with NB.     

奥沙利铂神经毒性机制及预测

 作为大肠癌的主要化疗药物之一,奥沙利铂的应用正逐步扩展到其他肿瘤的治疗中,然而奥沙利铂相关外周神经病变却限制了其临床应用。奥沙利铂神经毒性的机制尚未明确,最新研究认为急性神经毒性是通过改变Na+短暂电导介导的;体外实验证实了丝裂原活化蛋白激酶(MAPK)在奥沙利铂慢性神经病变中的作用。多种指标可用于预测奥沙利铂相关的外周神经病变,为实现个体化药物治疗、提高化疗的连续性带来了希望。     

Acetyl-L-Carnitine prevents and reverts experimental chronic neurotoxicity induced by oxaliplatin, without altering its antitumor properties

BACKGROUND: Oxaliplatin (OHP) is severely neurotoxic and induces the onset of a disabling sensory peripheral neuropathy. Acetyl-L-carnitine (ALC), a natural compound with neuroprotective action, was tested to determine whether it plays a protective role in OHP-induced neuropathy. MATERIALS AND METHODS: Peripheral neuropathy was induced in Wistar rats, and the effect of OHP alone or in combination with ALC was assessed, using behavioral and neurophysiological methods. Moreover, ALC interference on OHP antitumor activity was investigated using several in vitro and in vivo models. RESULTS: ALC-co-treatment reduced the neurotoxicity of OHP when it was coadministered. Furthermore, the administration-of OHP, once OHP-induced neuropathy was established, significantly mitigated its severity. Finally, experiments in different tumor systems indicated that ALC does not interfere with the antitumor effects of OHP. CONCLUSION: ALC is effective in the prevention and treatment of chronic OHP-induced peripheral neurotoxicity in an experimental rat model.     

Cisplatin induces serotonin release from human peripheral blood mononuclear cells of cancer patients and methylprednisolone inhibits this effect

The aim of this study was to verify whether cisplatin (CDDP) can induce serotonin (5HT) release from peripheral blood mononuclear cells (PBMC) of cancer patients and determine whether methylprednisolone (MP) can inhibit such release. Ten patients (mean age 61.8 years) with cancer of different sites, all but one in advanced stage of disease were studied. Our study showed that unstimulated PBMC of cancer patients release a higher amount of 5HT than that of healthy subjects (57+/-5 nM vs 10+/-1 nM, p<0.001) and that similarly the stimulation with PHA or CDDP induces a higher amount of 5HT release by PBMC of cancer patients than that by PBMC of healthy subjects (74+/-6 vs 32+/-3 nM, p<0.001 and 91+/-8 vs 18+/-2 nM, p<0.001, respectively). The addition of MP to the culture in the presence of CDDP induced a significant decrease of 5HT levels: from 91+/-8 to 53+/-7 nM, p=0.002. This result obtained in cancer patients paralleled that previously obtained by us in healthy subjects. Our data confirm a new mechanism through which CDDP could induce emesis and provide a further possible explanation to the anti-emetic activity of corticosteroids, such as MP.     

Cisplatin neurotoxicity: the relationship between dosage, time, and platinum concentration in neurologic tissues, and morphologic evidence of toxicity.

PURPOSE: To identify the major sites of platinum accumulation within neural tissues after treatment with cisplatin and to determine the relationship between cumulative dosage, time, and the development of histopathological and clinical neurotoxicity. PATIENTS AND METHODS: Twenty-one patients treated antemortem with cisplatin had neural tissue harvested at autopsy. Neural tissues were assayed for platinum and examined for histopathologic evidence of neurotoxicity. The relationship between histopathologic neurotoxicity and various pharmacologic parameters was analyzed. RESULTS: Tissue platinum levels were found to be highest in the dorsal root ganglia and lowest in tissue protected by the blood-brain barrier. For peripheral nerve, dorsal root, and dorsal root ganglia, a linear relationship was observed between platinum levels and cumulative dose. Platinum levels in neural tissue were not observed to decrease with time. Histopathologic toxicity closely matched an index of exposure to platinum (cumulative dose and log of time). Clinical and histopathologic neurotoxicity was found to occur with higher accumulations of platinum, with the highest levels found in patients with clinical evidence of neurotoxicity. CONCLUSIONS: The dorsal root ganglia was the most vulnerable neural structure. This is consistent with the clinical presentation of sensory neuropathy in cisplatin neurotoxicity. Central structures of the spinal cord and brain were protected from platinum accumulation. The increasing histopathologic toxicity, with an index of exposure to platinum, suggests that it is retained indefinitely in an actively neurotoxic form. The pharmacologic parameters examined correlate with the development of and are consistent with the clinical and laboratory features of cisplatin neurotoxicity.     

促红细胞生成素及受体在肿瘤中的研究进展

近年来,在多种非造血组织及肿瘤中发现了促红细胞生成素(EPO)及其受体。EPO对促红细胞生成的作用是已知的,然而,在肿瘤和非造血组织中,这种激素被认为可以刺激血管生成,促进细胞增殖,抑制细胞凋亡。本文主要阐述EPO在肿瘤中的作用及机制,总结EPO与肿瘤的相关性,为进一步研究EPO对肿瘤的影响提供理论依据。     

血小板因子4对巨核细胞的保护作用及其在肿瘤化疗中的意义

目的：研究血小板因子４对造血细胞的艇及其机制。方法：用液体或半固体培养法及流式细胞术测定血小板因子４对ＣＤ３４阳性脐血细胞的增殖与分化的作用。结果：血小反因子４可逆性地抑制ＣＤ３４阳性细胞向巨核细胞的发育。这种抑制可保留更多的巨核系干细胞并使其对５－氟尿嘧啶具有更强的抗性。血小板因子４还可抑制的血小板生成素诱导的巨核细胞生长。结论：血小板因子４通过调控血小板生成素的作用而使一些巨核细胞祖细胞 发育