替吉奥治疗结肠癌的研究

目的:探讨替吉奥治疗结肠癌的疗效。方法:75例经病理组织学确诊的结肠癌患者,分为A、B、C组。A组:替吉奥联合奥沙利铂(艾恒)25例。B组:5-Fu/LV联合奥沙利铂(艾恒)25例。C组:替吉奥单药治疗25例。观察疗效、疾病控制率及不良反应。结果:A组、C组与B组对比,不良反应发生率明显降低。A组有效率48%,疾病控制率88%。B组有效率28%,疾病控制率84%。C组有效率32%,疾病控制率80%。结论:替吉奥是结肠癌辅助化疗联合用药及单药治疗老年结直肠癌较好的治疗药物。     

替吉奥治疗结肠癌的研究

目的：探讨替吉奥治疗结肠癌的疗效。方法：75例经病理组织学确诊的结肠癌患者,分为A、B、C组。A组：替吉奥联合奥沙利铂（艾恒）25例。B组：5-Fu／LV联合奥沙利铂（艾恒）25例。C组：替吉奥单药治疗25例。观察疗效、疾病控制率及不良反应。结果：A组、C组与B组对比,不良反应发生率明显降低。A组有效率48％,疾病控制率88％。B组有效率28％,疾病控制率84％。C组有效率32％,疾病控制率80％。结论：替吉奥是结肠癌辅助化疗联合用药及单药治疗老年结直肠癌较好的治疗药物。     

四种不同化疗方案在侵蚀性葡萄胎患者中的疗效比较及药物经济学评价

目的:观察4种不同的化疗方案对侵蚀性葡萄胎的疗效并进行物经济学比较。方法:回顾性分析2014年01月至2017年01月我院收治的侵蚀性葡萄胎患者76例,分为甲氨蝶呤(MTX)组、EMA-CO组、新福菌素组(ACT)、5-氟尿嘧啶(5-Fu)+新福菌素组,观察4组患者治疗后的疗效、安全性,并采用成本-效果分析方法进行药物经济学分析。结果:4组患者在年龄、治疗花费、疗效间没有差异。MTX组药费最低(5876.5±644.9元,P0.01),成本-效果比最低(286.74元),但MTX组的化疗的副反应(骨髓抑制)发生率最高;其他三组同MTX组相比,其增量成本-效果比均2000元。联合化疗方案中,EMA-CO较5-Fu+ACT组药费较低(36027.2±1792.2元vs 60215.2±3632.8元,P0.01),增量成本效果优势明显(2542.69元vs 7963.19元)。结论:对于侵蚀性葡萄胎患者,针对患者的不同情况采用联合化疗或单药化疗,其疗效均无显著性差异。MTX组治疗花费最为经济,其他组增量成本-效果较高,考虑到副反应发生率、住院天数等其他因素,其他三组仍有选择优势。     

A Well-Circumscribed Border with Peripheral Doppler Signal in Sonographic Image Distinguishes Epithelioid Trophoblastic Tumor from Other Gestational Trophoblastic Neoplasms

As epithelioid trophoblastic tumor (ETT) shares similar clinical features with other gestational trophoblastic neoplasms (GTNs), it is likely to be clinically misdiagnosed and subsequently treated in an improper way. This study aimed to identify the sonographic features of ETT that are distinct from other GTNs, including placental site trophoblastic tumor (PSTT) and invasive mole/choriocarcinoma (IM/CC). Here, we retrospectively analyzed ultrasound images of 12 patients with ETT in comparison with those of 21 patients with PSTT and 24 patients with IM/CC. The results showed that maximal diameter and hemodynamic parameters were not significantly different among ETT, PSTT and IM/CC (P>0.05). However, a well-circumscribed border with hypoechogenic halo was identified in the gray-scale sonogram in all 12 cases of ETT, while only in 1 out of 21 cases of PSTT and 1 out of 16 cases of IM/CC (P<0.001 for ETT vs. PSTT or IM/CC). Moreover, a peripheral pattern of Doppler signals was observed in 11 out of 12 ETT lesions, showing relatively more Doppler signal spots around the tumor border than within the boundary, while a non-peripheral pattern of Doppler signals in all 21 PSTT cases and 14 out of 16 IM/CC cases: with minimal, moderate or remarkable signal spots within the tumor, but not along the tumor (P<0.001 for ETT vs. PSTT or IM/CC). These distinct sonographic features of ETT correlated with histopathologic observations, such as expansive growth pattern and vascular morphology. Thus, we draw the conclusions that the well-circumscribed border with peripheral Doppler signal may serve as a reliable sonographic feature to discriminate ETT from other types of GTNs. With further validation in a larger patient set in our ongoing multi-center study, this finding will be potentially developed into a non-invasive pre-operative GTN subtyping method for ETT.     

替吉奥联合阿帕替尼对晚期复发转移食管癌患者T细胞亚群和血清肿瘤标志物水平的影响

摘要 目的：观察晚期复发转移食管癌经阿帕替尼联合替吉奥治疗后的疗效及对患者T细胞亚群和血清肿瘤标志物水平的影响。方法：病例搜集时间为2015年3月至2018年3月,病例搜集范围为我院接收的晚期复发转移食管癌患者70例。采用信封抽签法将患者分为对照组和实验组,各为35例。对照组给予替吉奥治疗,实验组在对照组的基础上联合阿帕替尼治疗,两组均连续化疗2个周期。对比两组化疗2个周期后的客观缓解率、疾病控制率;对比两组化疗前、化疗2个周期后的T细胞亚群和血清肿瘤标志物水平;对比两组中位总生存期（mOS）、中位无进展生存期（mPFS）及生命质量评分,记录两组化疗期间毒副反应发生情况。结果：实验组的客观缓解率45.71%、疾病控制率68.57%高于对照组的22.86%、42.86%（P<0.05）。两组化疗2个周期后CD3⁺、CD4⁺、CD4⁺/ CD8⁺均较化疗前降低,但实验组高于对照组（P<0.05）;CD8⁺较化疗前升高,但实验组低于对照组（P<0.05）。两组化疗2个周期后肿瘤特异性生长因子（TSGF）、癌胚抗原（CEA）、糖类抗原199（CA199）较化疗前降低,且实验组低于对照组（P<0.05）。实验组的mOS、mPFS长于对照组（P<0.05）,两组化疗结束后3个月QLQ-OES24评分均升高,且实验组高于对照组（P<0.05）。两组不良反应发生率对比,差异无统计学意义（P>0.05）。结论：晚期复发转移食管癌经阿帕替尼联合替吉奥治疗后,病情得到有效控制,血清肿瘤标志物水平降低更为显著,同时还可减轻免疫抑制,延长mOS、mPFS,且不增加毒副反应,近期疗效可靠。     

Efficacy and tolerability of Sorafenib plus metronomic chemotherapy S-1 for advanced hepatocellular carcinoma in preclinical and clinical assessments

ObjectiveAlthough sorafenib, a molecular targeted agent, has survival benefits for advanced hepatocellular carcinoma (HCC) patients, its disease control rate remains limited. To explore the potential for augmenting its antitumor effect, we assessed the preclinical and clinical efficacy and tolerability of S-1 metronomic chemotherapy (MC) plus sorafenib.MethodsAntitumor effects and toxicity of this combination were tested with HAK-1B xenograft and spontaneous HCC mouse models, and a prospective pilot study was performed to compare therapeutic effects and safety between sorafenib plus MC S-1 for 12 advanced HCC cases and the historical control of 363 sorafenib-treated advanced HCC patients at our hospital from July 2011 to June 2015.ResultsIn mice, the combination chemotherapy enhanced anti-angiogenic effects, resulting in a stronger tumor hypoxic environment and increased tumor cell apoptosis. Clinically, the objective response rate of the combination chemotherapy was higher than that of sorafenib mono therapy (16.7%; 2/12 vs 5.2%; 19/363, p < 0.05); however, there were no significant differences in overall survival and time to progression. Adverse events including alopecia, thrombocytopenia, and pancreatic enzymes elevation in the combination chemotherapy were higher than those of sorafenib. No patient treated with the combination chemotherapy discontinued treatment due to severe adverse events.ConclusionsSorafenib plus MC S-1 seems to be effective and tolerable for patients with advanced HCC and could be considered a treatment option for these patients.     

树突状细胞对小剂量化疗疗效影响的基础研究

目的 研究树突状细胞对小剂量化疗疗效的影响,探讨小剂量化疗的可能机制.方法 以615小鼠的前胃癌细胞株(MFC)造模,在体外用rmGM-CSF和rmIL-4从荷瘤小鼠骨髓细胞分化、诱导未成熟树突状细胞.分为4组:小剂量化疗组、树突状细胞组、小剂量化疗+树突状细胞组、对照组,以BAX试剂盒检测肿瘤凋亡情况.在瘤体内注射树突状细胞,计算抑瘤率、特异性细胞毒性T淋巴细胞(CTL)的增殖及其对肿瘤细胞的特异性杀伤作用.结果 小剂量化疗能诱导肿瘤细胞凋亡,BAX 基因产物表达增多.注射侧抑瘤率小剂量化疗+DC组、小剂量化疗组、DC组分别为100%、67.22%和57.98%.对侧抑瘤率小剂量化疗+DC组、小剂量化疗组、DC组分别为87.58%、59.69%和48.24%.体内凋亡肿瘤细胞致敏的DC能显著刺激T淋巴细胞增殖,其诱导的CTL对MFC有显著的杀伤作用,在效靶比为40∶ 1、20∶ 1、10∶ 1和5∶ 1时72 h杀伤率分别为87.64%、70.32%、34.63%和13.87%.并能特异性杀伤小鼠前胃癌细胞MFC(P<0.01).结论 小剂量化疗的机制与肿瘤细胞凋亡及免疫促进有一定的相关.     

Nitroglycerin Tolerance in Caveolin-1 Deficient Mice

Nitrate tolerance developed after persistent nitroglycerin (GTN) exposure limits its clinical utility. Previously, we have shown that the vasodilatory action of GTN is dependent on endothelial nitric oxide synthase (eNOS/NOS3) activity. Caveolin-1 (Cav-1) is known to interact with NOS3 on the cytoplasmic side of cholesterol-enriched plasma membrane microdomains (caveolae) and to inhibit NOS3 activity. Loss of Cav-1 expression results in NOS3 hyperactivation and uncoupling, converting NOS3 into a source of superoxide radicals, peroxynitrite, and oxidative stress. Therefore, we hypothesized that nitrate tolerance induced by persistent GTN treatment results from NOS3 dysfunction and vascular toxicity. Exposure to GTN for 48–72 h resulted in nitrosation and depletion (>50%) of Cav-1, NOS3 uncoupling as measured by an increase in peroxynitrite production (>100%), and endothelial toxicity in cultured cells. In the Cav-1 deficient mice, NOS3 dysfunction was accompanied by GTN tolerance (>50% dilation inhibition at low GTN concentrations). In conclusion, GTN tolerance results from Cav-1 modification and depletion by GTN that causes persistent NOS3 activation and uncoupling, preventing it from participating in GTN-medicated vasodilation.     

5-Fluorouracil induced dysregulation of the microbiome-gut-brain axis manifesting as depressive like behaviors in rats

Disturbances of the gut microbiome have been widely suggested to be associated with 5-fluorouracil (5-Fu) induced digestive pathologies. Furthermore, it has been elucidated that the gut microbiome may play a key role in the pathogenesis of depressive disorders via the microbiota-gut-brain axis. Despite the speculation, there exists no direct evidence proving the causality between disturbances in the gut microbiome induced by 5-Fu and depressive mood dysregulation. Herein, behavioral testing was used to evaluate depressive-like behaviors in 5-Fu treated rats. Subsequently, the gut microbiota and prefrontal cortex (PFC) metabolic were analyzed by 16S rRNA sequencing and ¹H nuclear magnetic resonance (¹H NMR). To clarify the association between the gut microbiota and their role on depressive-like behaviors caused by 5-Fu, a fecal microbiota transplantation (FMT) experiment was carried out. The results suggested that 5-Fu could significantly alter the diversity and abundance of the gut microbiome, and induce PFC metabolic disorders, as well as depressive behaviors in rats. Transplantation of fecal microbiota from healthy control into 5-Fu treated rats significantly alleviated the PFC metabolic disorder and depressive-like behaviors. In conclusion, this study demonstrated that the gut microbiome was actively involved in the occurrence of 5-Fu induced depressive-like behaviors, and manipulation of specific gut microbiome parameters may serve as a promising novel target for side effects of 5-Fu treatment.     

Antioxidants decrease the apoptotic effect of 5-Fu in colon cancer by regulating Src-dependent caspase-7 phosphorylation

Although the rate of development of drug resistance remains very high, 5-fluorouracil (5-Fu) is still the most common chemotherapeutic drug used for the treatment of colon cancer. A better understanding of the mechanism of why cancers develop resistance to 5-Fu could improve its therapeutic effect. Sometimes, antioxidants are used simultaneously with 5-Fu treatment. However, a recent clinical trial showed no advantage or even a harmful effect of combining antioxidants with 5-Fu compared with administration of 5-Fu alone. The mechanism explaining this phenomenon is still poorly understood. In this study, we show that 5-Fu can induce reactive oxygen species-dependent Src activation in colon cancer cells. Mouse embryonic fibroblasts that are deficient in Src showed a clear resistance to 5-Fu, and knocking down Src protein expression in colon cancer cells also decreased 5-Fu-induced apoptosis. We found that Src could interact with and phosphorylate caspase-7 at multiple tyrosine sites. Functionally, the tyrosine phosphorylation of caspase-7 increases its activity, thereby enhancing cellular apoptosis. When using 5-Fu and antioxidants together, Src activation was blocked, resulting in decreased 5-Fu-induced apoptosis. Our results provide a novel explanation as to why 5-Fu is not effective in combination with some antioxidants in colon cancer patients, which is important for clinical chemotherapy.     

Basic and Clinical Research on the Therapeutic Effect of Intervention in Primary Liver Cancer by Targeted Intra-Arterial Verapamil Infusion

The aim of this study was assess the therapeutic effect of targeted intra-arterial verapamil infusion in liver cancer patients and its side-effects in a dog model. The blood verapamil levels in dogs were determined after one-off intra-arterial infusion (0.7 mg/kg). Blood pressure, breathing state, and II-lead electrocardiogram were measured. Primary liver cancer patients (100) were randomly assigned into two groups. Controls (50) were treated with targeted intra-arterial infusion, and every patient received once-a-month interventional therapy, twice. Treatment group (50) received chemotherapeutics plus verapamil. Therapeutic and toxic side effects were evaluated. Control (41) and treatment group (45) patients were further treated with a second round of targeted intra-arterial infusion of chemotherapeutics plus verapamil, in 30 days after the 2-time interventional therapy. Every patient accepted interventional therapy 4–5 times during the 6 months after the first confirmed diagnosis. Following verapamil infusion, verapamil in dog liver was tenfold higher than in blood and was 4- to 20-fold higher than that needed for reversing carcinoma drug resistance. After interventional therapy, there were no significant changes in iconographic evaluation indices between the groups. Average activities of aminotransferases were 332 and 178 U/l in the treatment and control groups (P < 0.05). The imaging parameters of the treatment group were significantly better than those of control group. No side effects were found among the 91 patients who accepted verapamil infusion. After verapamil infusion, verapamil levels in dog hepatic tissue exceeded the effective concentration that reverses carcinoma multidrug resistance without any visible changes in the vital signs. Targeted intra-arterial verapamil infusion could improve the chemotherapy for the primary liver cancer patients without any side effects.     

Localization of human sarcoma with radiolabeled monoclonal antibody

Summary We performed a randomized controlled study of postoperative adjuvant immunochemotherapy with Nocardia rubra cell wall skeleton (N-CWS) and Tegafur for gastric carcinoma between September 1979 and March 1983. A total of 309 patients were entered into this trial. Of the 309 patients, there were 98 evaluable patients in the chemotherapy group and 115 evaluable patients in the immunochemotherapy group. In both groups, Tegafur was given as chemotherapy at a daily dose of 400 to 800 mg, starting at 24–29 days after gastrectomy. In the immunochemotherapy group, 400 g of N-CWS was injected i. d. within the 2nd postoperative week. It was given weekly during the first month and subsequently monthly for as long as practicable. The patients were surveyed for length of survival in March 1985. The postoperative survival rate was analyzed for all cases, and for patients with various histopathological stages of carcinoma for comparison between the two treatment groups. No statistical difference was detected between the two groups in terms of age, sex, surgical curabilities, or stage of carcinoma. The overall survival rate for all patients was significantly higher in the immunochemotherapy group than in the chemotherapy group (p<0.05). With stage III plus IV disease, 53 patients from the chemotherapy group and 61 patients from the immunochemotherapy group were included for the analysis. As a consequence, a highly significant survival rate was observed in patients with stage III plus IV carcinoma in the immunochemotherapy group (p<0.005) as compared to the chemotherapy group. The overall 5-year (1800 days) survival rate after surgical treatment was 60.2% for the chemotherapy group and 73.2% for the immunochemotherapy group. In patients with stage III plus IV disease, the 5-year survival rates of the two treatment groups were 28.8% and 52.4%, respectively. Accordingly, the 50% survival period of patients with stage III plus IV cancer was 1800 days or more in the immunochemotherapy group, whereas it was only 722 days in the chemotherapy group. These results emphasize the effectiveness of N-CWS as an adjuvant immunotherapeutic agent in postoperative gastric cancer patients.The main side effects of N-CWS were skin lesions in the injected sites and fever, but these were temporary and not serious.     

Coarse Woody Debris Increases Microbial Community Functional Diversity but not Enzyme Activities in Reclaimed Oil Sands Soils

Forest floor mineral soil mix (FMM) and peat mineral soil mix (PMM) are cover soils commonly used for upland reclamation post open-pit oil sands mining in northern Alberta, Canada. Coarse woody debris (CWD) can be used to regulate soil temperature and water content, to increase organic matter content, and to create microsites for the establishment of microorganisms and vegetation in upland reclamation. We studied the effects of CWD on soil microbial community level physiological profile (CLPP) and soil enzyme activities in FMM and PMM in a reclaimed landscape in the oil sands. This experiment was conducted with a 2 (FMM vs PMM) × 2 (near CWD vs away from CWD) factorial design with 6 replications. The study plots were established with Populus tremuloides (trembling aspen) CWD placed on each plot between November 2007 and February 2008. Soil samples were collected within 5 cm from CWD and more than 100 cm away from CWD in July, August and September 2013 and 2014. Microbial biomass was greater (p<0.05) in FMM than in PMM, in July, and August 2013 and July 2014, and greater (p<0.05) near CWD than away from CWD in FMM in July and August samplings. Soil microbial CLPP differed between FMM and PMM (p<0.01) according to a principal component analysis and CWD changed microbial CLPP in FMM (p<0.05) but not in PMM. Coarse woody debris increased microbial community functional diversity (average well color development in Biolog Ecoplates) in both cover soils (p<0.05) in August and September 2014. Carbon degrading soil enzyme activities were greater in FMM than in PMM (p<0.05) regardless of distance from CWD but were not affected by CWD. Greater microbial biomass and enzyme activities in FMM than in PMM will increase organic matter decomposition and nutrient cycling, improving plant growth. Enhanced microbial community functional diversity by CWD application in upland reclamation has implications for accelerating upland reclamation after oil sands mining.     

替吉奥联合奥沙利铂及多西紫杉醇治疗晚期胃癌的临床疗效和安全性评估

目的:观察替吉奥联合奥沙利铂及多西紫杉醇治疗晚期胃癌的近期疗效,并对其用药安全性进行评估。方法:选取2010年8月—2012年8月在我院接受治疗的晚期胃癌患者68例,随机分为对照组和观察组,每组34例。对照组患者采取5-FU+奥沙利铂+多西紫杉醇进行治疗,而观察组患者给予替吉奥+奥沙利铂+多西紫杉醇进行治疗,比较两组患者接受不同药物治疗所得到的近期疗效及不良反应的发生情况。结果:观察组治疗的总有效率为58.82%,而对照组治疗的总有效率为32.35%,观察组明显高于对照组,差异显著,具有统计学意义(P0.05);观察组患者治疗后的不良反应发生率为8.82%,而对照组患者治疗后的不良反应发生率为32.35%,观察组明显低于对照组,差异显著,具有统计学意义(P0.05)。结论:替吉奥联合奥沙利铂及多西紫杉醇治疗晚期胃癌疗效显著,不良反应少,患者耐受良好,值得进一步推广和应用。     

The Combination of a Low-Dose Chemotherapeutic Agent, 5-Fluorouracil,and an Adenoviral Tumor Vaccine Has a Synergistic Benefit on Survival in a Tumor Model System

Standard cancer therapies, particularly those involving chemotherapy, are in need of modifications that both reduce short-term and long-term side effects as well as improve the overall survival of cancer patients. Here we show that combining low-dose chemotherapy with a therapeutic vaccination using an adenovirus encoding a model tumor-associated antigen, ovalbumin (Ad5-OVA), had a synergistic impact on survival in tumor-challenged mice. Mice that received the combinatorial treatment of Ad5-OVA plus low-dose 5-fluorouracil (5-FU) had a 95% survival rate compared to 7% and 30% survival rates for Ad5-OVA alone and 5-FU alone respectively. The presence of 5-FU enhanced the levels of OVA-specific CD8⁺ T lymphocytes in the spleens and draining lymph nodes of Ad5-OVA-treated mice, a phenomenon that was dependent on the mice having been tumor-challenged. Thus 5-FU may have enhanced survival of Ad5-OVA-treated mice by enhancing the tumor-specific immune response combined with eliminating tumor bulk. We also investigated the possibility that the observed therapeutic benefit may have been derived from the capacity of 5-FU to deplete MDSC populations. The findings presented here promote the concept of combining adenoviral cancer vaccines with low-dose chemotherapy.     

14-3-3σ regulation by p53 mediates a chemotherapy response to 5-fluorouracil in MCF-7 breast cancer cells via Akt inactivation

We previously demonstrated that 14-3-3σ was downregulated in 5-fluorouracil (5-Fu)-resistant MCF-7 breast cancer cells (MCF-7/5-Fu). Here, we found that stably enhanced 14-3-3σ expression strengthened the effects of 5-Fu, Mitoxantrone and cDDP. 14-3-3σ stabilised the p53 protein and bound Akt to inhibit its activity and its downstream targets: survivin, Bcl-2 and NF-κB-p50. In addition, decreased p53 expression, but not promoter hypermethylation, was responsible for the downregulation of 14-3-3σ in MCF-7/5-Fu cells. Meanwhile, initial treatments with high concentrations of 5-Fu clearly induced 14-3-3σ and p53 expression in a time-dependent manner. 14-3-3σ-mediated molecular events that synergise with p53 may play important roles in the chemotherapy of breast cancer.     

Biotransformation of glyceryl trinitrate by rat brain homogenate.

Incubation of glyceryl trinitrate (GTN) with 5% (w/v) rat brain homogenate (RBH) resulted in biotransformation of the organic nitrate vasodilator drug to a mixture of glyceryl-1,2-dinitrate (1,2-GDN) and glyceryl-1,3-dinitrate (1,3-GDN). Heating of the RBH at 100 degrees C for 5 min and (or) pretreatment with 5 mM N-ethylmaleimide at 37 degrees C for 10 min demonstrated that about two-thirds of the GTN biotransformation activity was due to a sulfhydryl-dependent enzymatic process resulting in the predominant formation of 1,2-GDN, and that the remaining biotransformation activity was due to a sulfhydryl-dependent nonenzymatic process resulting in the selective formation of 1,3-GDN. In a preliminary experiment, nitric oxide formation was observed during the incubation of GTN with RBH under anaerobic conditions. These data support the idea that some of the therapeutic and adverse effects of GTN are mediated through its action in the central nervous system.     

Fibroblast-Derived Exosomes Contribute to Chemoresistance through Priming Cancer Stem Cells in Colorectal Cancer

Chemotherapy resistance observed in patients with colorectal cancer (CRC) may be related to the presence of cancer stem cells (CSCs), but the underlying mechanism(s) remain unclear. Carcinoma-associated fibroblasts (CAFs) are intimately involved in tumor recurrence, and targeting them increases chemo-sensitivity. We investigated whether fibroblasts might increase CSCs thus mediating chemotherapy resistance. CSCs were isolated from either patient-derived xenografts or CRC cell lines based on expression of CD133. First, CSCs were found to be inherently resistant to cell death induced by chemotherapy. In addition, fibroblast-derived conditioned medium (CM) promoted percentage, clonogenicity and tumor growth of CSCs (i.e., CD133+ and TOP-GFP+) upon treatment with 5-fluorouracil (5-Fu) or oxaliplatin (OXA). Further investigations exhibited that exosomes, isolated from CM, similarly took the above effects. Inhibition of exosome secretion decreased the percentage, clonogenicity and tumor growth of CSCs. Altogether, our findings suggest that, besides targeting CSCs, new therapeutic strategies blocking CAFs secretion even before chemotherapy shall be developed to gain better clinical benefits in advanced CRCs.     

Evidence for a relationship between mitochondrial Complex I activity and mitochondrial aldehyde dehydrogenase during nitroglycerin tolerance: Effects of mitochondrial antioxidants

The medical use of nitroglycerin (GTN) is limited by patient tolerance. The present study evaluated the role of mitochondrial Complex I in GTN biotransformation and the therapeutic effect of mitochondrial antioxidants. The development of GTN tolerance (in rat and human vessels) produced a decrease in mitochondrial O(2) consumption. Co-incubation with the mitochondria-targeted antioxidant mitoquinone (MQ, 10(-6)mol/L) or with glutathione ester (GEE, 10(-4)mol/L) blocked GTN tolerance and the effects of GTN on mitochondrial respiration and aldehyde dehydrogenase 2 (ALDH-2) activity. Biotransformation of GTN depended on the mitochondria being functionally active, particularly mitochondrial Complex I. Tolerance induced mitochondrial ROS production and oxidative stress, though these effects were not detected in HUVECρ(0) cells or Complex I mutant cells. Experiments performed to evaluate Complex I-dependent respiration demonstrated that its inhibition by GTN was prevented by the antioxidants in control samples. These results point to a key role for mitochondrial Complex I in the adequate functioning of ALDH-2. In addition, we have identified mitochondrial Complex I as one of the targets at which the initial oxidative stress responsible for GTN tolerance takes place. Our data also suggest a role for mitochondrial-antioxidants as therapeutic tools in the control of the tolerance that accompanies chronic nitrate use.     

Comparison of glyceryl trinitrate-induced with pentaerythrityl tetranitrate-induced in vivo formation of superoxide radicals: effect of vitamin C.

Glyceryl trinitrate (GTN) and pentaerythrityl tetranitrate (PETN) are among the most known organic nitrates that are used in cardiovascular therapy as vasodilators. However, anti-ischemic therapy with organic nitrates is complicated by the induction of nitrate tolerance. When nitrates are metabolized to release nitric oxide (NO), there is considerable coproduction of superoxide radicals in vessels leading to inactivation of NO. However, nitrate-induced increase of superoxide radical formation in vivo has not been reported. In this work, the authors studied the in vivo formation of superoxide radicals induced by treatment with PETN or GTN and determined the antioxidant effect of vitamin C. The formation of superoxide radicals was determined by the oxidation of 1-hydroxy-3-carboxy-pyrrolidine (CP-H) to paramagnetic 3-carboxy-proxyl (CP) using electron spin resonance spectroscopy. CP-H (9 mg/kg intravenous bolus and 0.225 mg/kg per minute continuous intravenous GTN or PETN 130 microg/kg) were infused into anesthetized rabbits. Every 5 min, blood samples were obtained from Arteria carotis to measure the CP formation. Both PETN and GTN showed similar vasodilator effects. Formation of CP in blood after infusions of GTN and PETN were 2.0+/-0.4 microM and 0.98+/-0.23 microM, respectively. Pretreatment with 30 mg/kg vitamin C led to a significant decrease in CP formation: 0.27+/-0.14 microM (vitamin C plus GTN) and 0.34+/-0.15 microM (vitamin C plus PETN). Pretreatment of animals with superoxide dismutase (15,000 units/kg) significantly inhibited nitrate-induced nitroxide formation. Therefore, in vivo infusion of GTN or PETN in rabbits increased the formation of superoxide radicals in the vasculature. PETN provoked a minimal stimulation of superoxide radical formation without simultaneous development of nitrate tolerance. The data suggest that the formation of superoxide radicals induced by organic nitrate correlates with the development of nitrate tolerance. The effect of vitamin C on CP formation leads to the conclusion that vitamin C can be used as an effective antioxidant for protection against nitrate-induced superoxide radical formation in vivo.