TRIM46 contributes to high glucose-induced ferroptosis and cell growth inhibition in human retinal capillary endothelial cells by facilitating GPX4 ubiquitination.

PURPOSE: Increased permeability of retinal capillary endothelial cells is a key feature in the progression of diabetic retinopathy (DR). Precisely why and how diabetes causes dysfunction in retinal capillary endothelial cells is not well understood, making it challenging to explore more advanced therapeutics. METHODS: Cell proliferation was assessed by the Cell Counting Kit-8 assay. Ferroptosis was evaluated by measuring lipid reactive oxygen species levels by flow cytometry and determining malondialdehyde, superoxide dismutase, and glutathione peroxidase levels through biochemical assays. Western blot analysis and quantitative PCR were respectively used to check the expression of proteins and RNAs. Co-immunoprecipitation assays were used to confirm the interaction between TRIM46 and GPX4. RESULTS: High glucose (HG, 25 mM glucose) significantly suppressed cell growth, which could be reversed by the ferroptosis inhibitor, ferrostatin-1. HG treatment time-dependently induced ferroptosis in human retinal capillary endothelial cells (HRCECs) and induced TRIM46 expression. Lentiviral-mediated overexpression of TRIM46 decreased cell resistance against HG-induced ferroptosis, whereas knockdown showed the opposite effect. Administration of RSL3, a ferroptosis agonist, was able to reverse the protective effects of TRIM46 silencing. TRIM46 interacted with GPX4, an important enzyme that suppresses ferroptosis, and promoted GPX4 ubiquitination. Furthermore, lentiviral-mediated overexpression ofGPX4 ameliorated the effects of TRIM46 overexpression and conferred protection to cells against HG-induced ferroptosis. CONCLUSION: TRIM46 and GPX4 form a regulatory pathway that controls HG-induced ferroptosis of HRCECs. Inhibiting this pathway or sustaining the expression of GPX4 enables cells to resist damage caused by HG. We provide new mechanistic insight into the pathology of DR and identified TRIM46 and GPX4 as two molecular targets for the development of effective drugs for DR treatment.

Growth suppression of human oral cancer cells by candidate agents for cetuximab-side effects.

Cetuximab, an inhibitor of the epidermal growth factor receptor that is used widely to treat human cancers including oral squamous cell carcinoma (OSCC), has characteristic side effects of skin rash and hypomagnesemia. However, the mechanisms of and therapeutic agents for skin rashes and hypomagnesemia are still poorly understood. Our gene expression profiling analyses showed that cetuximab activates the p38 MAPK pathways in human skin cells (human keratinocyte cell line [HaCaT]) and inhibits c-Fos-related signals in human embryonic kidney cells (HEK293). We found that while the p38 inhibitor SB203580 inhibited the expression of p38 MAPK targets in HaCaT cells, flavagline reactivated c-Fos-related factors in HEK293 cells. It is noteworthy that, in addition to not interfering with the effect of cetuximab by both compounds, flavagline has additive effect for OSCC growth inhibition in vivo. Collectively, our results indicate that combination of cetuximab and these potential therapeutic agents for cetuximab-related toxicities could be a promising therapeutic strategy for patients with OSCC.

Actinomycin-D and dimethylamino-parthenolide synergism in treating human pancreatic cancer cells.

Preclinical Research & Development Pancreatic cancer is the third leading cause of death in the US with a poor 5-year survival rate of 8.5%. A novel anti-cancer drug, dimethylamino parthenolide (DMAPT), is the water-soluble analog of the natural sesquiterpene lactone, parthenolide. The putative modes of action of DMAPT are inhibition of the Nuclear chain factor kappa-light-chain enhancer of activated B cells (NFκB) pathway and depletion of glutathione levels; the latter causing cancer cells to be more susceptible to oxidative stress-induced cell death. Actinomycin-D (ActD) is a polypeptide antibiotic that binds to DNA, and inhibits RNA and protein synthesis by inhibiting RNA polymerase II. A phase 2 clinical trial indicated that ActD could be a potent drug against pancreatic cancer; however, it was not a favored drug due to toxicity issues. New drug entities and methods of drug delivery, used alone or in combination, are needed to treat pancreatic cancer more effectively. Thus, it was postulated that combining DMAPT and ActD would result in synergistic inhibition of Panc-1 pancreatic cancer cell growth because DMAPT's inhibition of NFκB would enhance induction of apoptosis by ActD, via phosphorylation of c-Jun, by minimizing NFκB inhibition of c-Jun phosphorylation. Combining these two drugs induced a higher level of cell death than each drug alone. A fixed drug ratio of DMAPT: ActD (1,200:1) was used. Data from metabolic (MTT) and colony formation assays were analyzed for synergism with CompuSyn software, which utilizes the Chou-Talalay equation. The analyses indicated synergism and moderate synergism at combination concentrations of DMAPT/ActD of 12/0.01 and 18/0.015 µM, respectively.

IFN-γ promotes muscle damage in the mdx mouse model of Duchenne muscular dystrophy by suppressing M2 macrophage activation and inhibiting muscle cell proliferation.

Duchenne muscular dystrophy is a degenerative disorder that leads to death by the third decade of life. Previous investigations have shown that macrophages that invade dystrophic muscle are a heterogeneous population consisting of M1 and M2 macrophages that promote injury and repair, respectively. In the present investigation, we tested whether IFN-γ worsens the severity of mdx dystrophy by activating macrophages to a cytolytic M1 phenotype and by suppressing the activation of proregenerative macrophages to an M2 phenotype. IFN-γ is a strong inducer of the M1 phenotype and is elevated in mdx dystrophy. Contrary to our expectations, null mutation of IFN-γ caused no reduction of cytotoxicity of macrophages isolated from mdx muscle and did not reduce muscle fiber damage in vivo or improve gross motor function of mdx mice at the early, acute peak of pathology. In contrast, ablation of IFN-γ reduced muscle damage in vivo during the regenerative stage of the disease and increased activation of the M2 phenotype and improved motor function of mdx mice at that later stage of the disease. IFN-γ also inhibited muscle cell proliferation and differentiation in vitro, and IFN-γ mutation increased MyoD expression in mdx muscle in vivo, showing that IFN-γ can have direct effects on muscle cells that could impair repair. Taken together, the findings show that suppression of IFN-γ signaling in muscular dystrophy reduces muscle damage and improves motor performance by promoting the M2 macrophage phenotype and by direct actions on muscle cells.

Induction of TGF-beta 1, not regulatory T cells, impairs antiviral immunity in the lung following bone marrow transplant.

Patients receiving hematopoietic stem cell transplantation or bone marrow transplantation (BMT) as therapy for various malignancies or autoimmune diseases have an increased risk for infectious complications posttransplant, especially in the lung. We have used BMT in mice and murine gammaherpesvirus, gammaHV-68, to study the efficacy of adaptive immune responses post-BMT. Five weeks posttransplant, mice have fully reconstituted their hematopoietic lineages in both the lung and periphery. When challenged with virus, however, BMT mice have a reduced ability to clear lytic virus from the lung. Defective viral control in BMT mice is not related to impaired leukocyte recruitment or defective APC function. Rather, BMT mice are characterized by defective CD4 cell proliferation, skewing of effector CD4 T cells from a Th1 to a Th17 phenotype, and an immunosuppressive lung environment at the time of infection that includes overexpression of TGF-beta1 and PGE(2) and increased numbers of regulatory T cells. Neither indomethacin treatment to block PG synthesis nor anti-CD25 depletion of regulatory T cells improved antiviral host defense post-BMT. Transplanting mice with transgenic bone marrow expressing a dominant-negative TGF-betaRII under the permissive CD4 promoter created mice in which effector CD4 and CD8 cells were unresponsive to TGF-beta1. Mice with TGF-beta1-nonresponsive effector T cells had restored antiviral immunity and improved Th1 responses post-BMT. Thus, our results indicate that overexpression of TGF-beta1 following myeloablative conditioning post-BMT results in impaired effector T cell responses to viral infection.

[Proteinuria and renal transplantation]. / Importance du suivi de la protéinurie chez le transplanté

The occurrence of proteinuria in transplant patients is a marker of poor prognosis. The augmentation of proteinuria is associated with an increased risk of patient death and graft loss. Even a low-level urinary protein excretion (0.5 g/d) has a highly significant negative impact on graft survival whether it is observed 1 or 3 months after transplantation. Urinary albumin excretion rate has also a major effect on risks of graft loss and death with functional kidney, macro-albuminuria increasing the risks of respectively 16.4 and 4.12 times comparatively to micro-albuminuria, which itself multiplies the risks by 14.2 and 5.5 respectively, compared to normo-albuminuria. In terms of factors causing proteinuria apparition, the role of proliferation signal inhibitors has been recently observed. Sirolimus, especially at high dose, in particular can induce the occurrence of proteinuria, which is reversible with treatment discontinuation, but only with a partial recovery of the renal function. Proteinuria may be explained by a direct glomerular impact of sirolimus on several podocyte markers.

Solid tumors subsequent to arsenic trioxide treatment for acute promyelocytic leukemia.

Arsenic trioxide (As(2)O(3)) is highly efficacious for acute promyelocytic leukemia (APL). Environmental arsenic exposure predisposes to malignancies, but the risk for therapeutic arsenic is undefined. Three APL patients (de novo, 2; therapy-related, 1) in a cohort of 59 cases given oral-As(2)O(3) for induction and maintenance treatment developed secondary cancers (nasopharyngeal carcinoma, 2; colonic adenocarcinoma, 1) at 16, 36 and 55 months post-As(2)O(3) therapy. Retrospective analysis of biomarkers (Epstein Barr virus serology and quantification, carcinoembryonic antigen) showed the potential presence of cancers before or shortly after As(2)O(3) therapy, suggesting that As(2)O(3) had not initiated these malignancies. Compared against matched background population, there was an increased risk of second cancer (p=0.012, standard incidence ratio=6.5; 95% confidence interval=1.4-19.0).

Effects of genistein, an isoflavone, on pregnancy outcome and organ weights of pregnant and lactating rats and development of their suckling pups.

There is a general agreement that isoflavones can be beneficial to health in adults. However, isoflavones are well known as endocrine-disrupting chemicals. It should be considered that soy foods might adversely affect the reproductive system and infants. The aim of this study was to evaluate the effects of genistein, an isoflavone, on dams and their offspring. Maternal rats were fed diets containing genistein at levels of 0 and 0.5 g/kg diet from pregnancy day 5 to postnatal day 13. No effects of genistein on the delivery, anogenital distance, reproductive organ weight, and body weight of the infants at birth were observed. There were no consistent effects on suckling pups after continuous genistein exposure during their fetal and suckling stages through their mothers, and there was no difference in effects according to the periods of exposure during pregnancy and lactation. We also observed no significant effect on the growth of offspring after weaning. Moreover, while we observed that the serum concentration of triiodothyronine (T3) in dams decreased, the result was a tendency, not a significant decrease. Our study suggested that maternal ingestion of genistein might have not induced serious adverse effects on dams, fetuses, infants or offspring during growth. However, the results indicated in many papers suggest the necessity of further study on the safety of genistein.

Suramin: a novel growth factor antagonist with activity in hormone-refractory metastatic prostate cancer.

PURPOSE: Suramin is known to inhibit the growth of malignant prostate carcinoma cells in vitro. This led us to evaluate the effectiveness of suramin in the treatment of 38 patients with prostate carcinoma refractory to hormone therapy. PATIENTS AND METHODS: Suramin was administered by continuous infusion at a rate designed to reach a peak of 300 micrograms/mL at the end of 14 days. Patients were given 8 weeks to recover from any toxicity before beginning the second cycle. Subsequent cycles were administered in the same manner except the starting dose rate was 280 mg/m2. RESULTS: In 17 patients with measurable soft tissue disease, three had complete disappearance of soft tissue disease for 4, 5, and 11 months, whereas three patients had a greater than or equal to 50% decrease in the sum of the products of the diameters of all measurable disease for greater than or equal to 1 month. Of these 17 patients, pretreatment prostate-specific antigen (PSA) decreased by 75% or more in five (29%) and normalized in one (6%). The remaining 21 patients had disease limited to bone, and only one of these experienced resolution of more than 50% of all lesions on bone scan. Of these 21 patients, pretreatment PSA decreased by 75% or more in eight (38%) and normalized in five (25%). Median time to progression for all patients was 26.3 weeks, and median survival was 42.3 weeks. Patients with bone involvement alone exhibited a better survival than patients with soft tissue involvement (P2 = .02). Survival was strongly correlated (P2 = .0001) with a decline in the pretreatment PSA of greater than or equal to 75% by the eighth week on therapy, with nearly an 85% survival at 1 year compared with a 20% survival for those whose pretreatment PSA did not decline by that amount. CONCLUSION: We conclude that suramin is an active agent in hormone-refractory prostate carcinoma.

c-raf-1 depletion and tumor responses in patients treated with the c-raf-1 antisense oligodeoxynucleotide ISIS 5132 (CGP 69846A).

Abnormally regulated signaling through proliferative signal transduction pathways characterizes many of the common solid tumors. The best described of these involves potentially oncogenic proteins of the Ras family, which activate Raf proteins in the early steps of the mitogen-activated protein kinase cascade. ISIS 5132, a phosphorothioate antisense oligodexoynucleotide directed to the 3' untranslated region of the c-raf-1 mRNA, inhibits the growth of human tumor cell lines in vitro and in vivo in association with specific down-regulation of target message expression. Using a semiquantitative reverse transcription-PCR assay, we analyzed changes in c-raf-1 mRNA expression in peripheral blood mononuclear cells collected from patients with advanced cancers treated with ISIS 5132 as part of a clinical trial. Specimens were collected for analysis pretreatment and on days 3, 5, 8, and 15 of the first cycle and on day 1 of each subsequent cycle. We observed significant reductions of c-raf-1 expression from baseline by day 3 in 13 of 14 patients (P = 0.002). The time course and depletion of c-raf-1 message in peripheral blood mononuclear cells paralleled the clinical benefit in two patients. These findings demonstrate that ISIS 5132 specifically reduces target gene expression in treated patients and that peripheral blood mononuclear cells are suitable tissues for biomarker studies in future trials.

Drug-eluting stent: a review and update.

The development of stent has been a major advance in the treatment of obstructive coronary artery disease since the introduction of balloon angioplasty. However, neointimal hyperplasia occurring within the stent leading to in-stent restenosis is a main obstacle in the long-term success of percutaneous coronary intervention (PCI). The recent introduction of drug-eluting stents (DES) contributes a major breakthrough to interventional cardiology. Many large randomized clinical trials using DES have shown a remarkable reduction in angiographic restenosis and target vessel revascularization when compared with bare metal stents. The results of these trials also appear to be supported by evidence from everyday practice and non-controlled clinical trials. However, the expanded applications of DES, especially in treating complex lesions such as left main trunk, bifurcation, saphenous vein graft lesions, or in-stent restenosis, are still under evaluation with ongoing studies. With the availability of different types of DES in the market, the issue of cost should not be a deterrent and DES will eventually be an economically viable option for all patients. The adoption of DES in all percutaneous coronary intervention may become a reality in the near future. In this review article, we summarize the recent development and progress of DES as well as compare and update the results of clinical trials.

Pygeum africanum for the treatment of patients with benign prostatic hyperplasia: a systematic review and quantitative meta-analysis.

PURPOSE: To conduct a systematic review and quantitative meta-analysis of the therapeutic efficacy and tolerability of Pygeum africanum in men with symptomatic benign prostatic hyperplasia. METHODS: Studies were identified through the search of Medline (1966 to 2000), Embase, Phytodok, the Cochrane Library, bibliographies of identified trials and review articles, and contact with relevant authors and drug companies. Randomized trials were included if participants had symptomatic benign prostatic hyperplasia, the intervention was a preparation of P. africanum alone or in combination with other phytotherapeutic agents, a control group received placebo or other pharmacologic therapies for benign prostatic hyperplasia, and treatment duration was at least 30 days. Two investigators independently extracted key data on design features, subject characteristics, and therapy allocation. RESULTS: A total of 18 randomized controlled trials involving 1,562 men met the inclusion criteria and were analyzed. Many studies did not report results in a method that permitted meta-analysis. Only 1 of the studies reported a method of treatment allocation concealment, although 17 were double-blinded. The mean study duration was 64 days (range 30 to 122). Compared with placebo in 6 studies, P. africanum provided a moderately large improvement in the combined outcome of urologic symptoms and flow measures as assessed by an effect size defined by the difference of the mean change for each outcome divided by the pooled standard deviation for each outcome (-0.8 SD [95% confidence interval (CI): -1.4 to -0.3]). Summary estimates of individual outcomes were also improved by P. africanum. Men were more than twice as likely to report an improvement in overall symptoms (risk ratio = 2.1, 95% CI: 1.40 to 3.1). Nocturia was reduced by 19% and residual urine volume by 24%; peak urine flow was increased by 23%. Adverse effects due to P. africanum were mild and similar to placebo. The overall dropout rate was 12% and was similar for P. africanum (13%), placebo (11%), and other controls (8%; P = 0.4 versus placebo and P = 0.5 versus other controls). CONCLUSIONS: The literature on P. africanum for the treatment of benign prostatic hyperplasia is limited by the short duration of studies and the variability in study design, the use of phytotherapeutic preparations, and the types of reported outcomes. However, the evidence suggests that P. africanum modestly, but significantly, improves urologic symptoms and flow measures. Further research is needed using standardized preparations of P. africanum to determine its long-term effectiveness and ability to prevent complications associated with benign prostatic hyperplasia.

Cardiotoxicity of the antiproliferative compound fluorouracil.

The antimetabolite fluorouracil (5-FU) is frequently administered for chemotherapy of various malignant neoplasms. The drug is well known for its adverse effects involving bone marrow, skin, mucous membranes, intestinal tract and central nervous system, whereas its cardiotoxicity is less familiar to clinicians. The pathophysiology of fluorouracil-associated cardiac adverse events is controversial and conclusions are based on clinical studies and case reports more than on solid experimental evidence. While clinical and electrocardiographic features suggest myocardial ischaemia as a main aetiological factor, possibly induced by coronary vasospasm, histomorphological and biochemical studies indicate a more direct drug-mediated cytotoxic action. Estimates of the overall incidence of fluorouracil cardiotoxicity have varied widely from 1.2 to 18% of patients. Patients may present with angina-like chest pain, cardiac arrhythmias or myocardial infarction. There is no unequivocally effective prophylaxis or treatment in this syndrome. Once fluorouracil administration is discontinued symptoms are usually reversible, although fatal events have been described. The overall mortality rate has been estimated to be between 2.2 and 13.3%. There is a high risk of relapse when patients are re-exposed to this drug following previous cardiac incidents. From the present data it is concluded that cardiotoxicity is a relevant but underestimated problem in fluorouracil treatment. Since the mechanisms of fluorouracil-associated cardiotoxicity are not yet fully understood, all patients undergoing this chemotherapy have to be carefully evaluated and monitored for cardiac risk factors and complaints. After cardiotoxic events, fluorouracil should definitely be withdrawn and replaced by an alternative antiproliferative regimen.

A phase II protection study of BB-10010 in patients with high grade non-Hodgkin's lymphoma undergoing intensive chemotherapy.

The aim of this study was to determine whether administration of BB-10010, a synthetic stem cell inhibitor, would allow more intensive chemotherapy to be administered to patients with newly diagnosed high grade NHL. Thirteen patients were randomised to receive BB-10010 concurrently with dose-intensified BEMOP/CA chemotherapy (7 patients) or chemotherapy alone (6 patients). Although the mean neutrophil count of BB-10010 treated patients was higher following cycles 1, 2 and 3 of chemotherapy compared with those receiving chemotherapy alone, there was no difference in the mean number of cycles tolerated, blood component usage and hospital admissions due to infections. No specific toxicity of BB-10010 was identified. Whilst BB-10010 can be administered safely, it does not improve the ability of patients to tolerate intensive chemotherapy for high grade NHL.

Novel biologic therapies for malignant gliomas. Antiangiogenesis, immunotherapy, and gene therapy.

Despite 20 years of clinical investigation of new surgical, radiotherapeutic, and chemotherapeutic approaches to the treatment of malignant gliomas, the prognosis for these patients remains dismal. New and innovative strategies are clearly required. The explosion of knowledge in molecular biology and our ever-increasing understanding of the molecular pathogenesis of neoplasia has opened up a number of new approaches to the treatment of brain tumors. The development and refinement of these strategies will require an unprecedented degree of collaboration and communication between the basic scientist, pharmaceutical/biotechnology companies, and clinical investigators. Most of all, the ability to identify novel and effective strategies will ultimately depend on the private clinician and his or her willingness to encourage patients with these tumors to participate in well-designed clinical trials that will test these novel strategies. With support from clinicians, and the close collaboration of investigators, it is hopeful that the next 20 years will bring significantly greater advances in the treatment of malignant gliomas than has ever been seen before.

The current use of estrogens for growth-suppressant therapy in adolescent girls.

OBJECTIVE: To assess the current prevalence of growth-suppressant therapy using oral estrogens for tall adolescent girls among U.S. pediatric endocrinologists. METHODS: A questionnaire was mailed to pediatric endocrinologists practicing in the United States, asking how many patients each clinician had recently treated for tall stature using oral estrogens, whether he/she continued to offer such treatment, reasons for offering or declining to offer it, criteria for initiating and terminating treatment, choice of estrogen, and typical doses, durations, and effects. RESULTS: Of 411 respondents, 92 (22%) reported having treated 1-5 girls for tall stature during the preceding five years. Only 4 (1%) had treated more than 5 cases during this period. Growth-suppression treatment was currently offered by 137 respondents (33.3%). Reasons for doing so included parents' and patients' concerns about stature and the adverse social effects of unusually tall stature. Reasons for not offering such treatments were that its long-term risks are unknown, that tall stature is not a disease, and a lack of referrals. Few clinicians initiated treatment if predicted mature height was below 183 cm. Treatment was typically terminated based on evidence of epiphyseal fusion, usually within less than two years, although extended treatments were common. Frequently reported adverse effects included weight gain, nausea/vomiting, areolar or nipple pigmentation, headache, and irregular menses. CONCLUSIONS: Although treatment is less commonly initiated than in the past, many pediatric endocrinologists continue to offer oral estrogens to suppress growth for tall adolescent girls.

Leflunomide, a new disease-modifying drug for treating active rheumatoid arthritis in methotrexate-controlled phase II clinical trial.

OBJECTIVE: To evaluate the efficacy and safety of leflunomide in comparison with methotrexate (MTX) on patients with rheumatoid arthritis (RA) in China. METHODS: Five hundred and sixty-six patients with active rheumatoid arthritis were randomly assigned to receive leflunomide at 20 mg once daily or MTX at 15 mg once weekly in a controlled trial. Five hundred and four patients completed the 12-week treatment and some patients continued the treatment for 24 weeks. RESULTS: Both leflunomide and MTX could improve the symptoms, signs, and joint function, but there were no changes in X-ray observations of patients with rheumatoid arthritis. In the leflunomide group, the overall rates of effectiveness at 12 weeks and 24 weeks were 86.94% and 92.31% respectively; the rates of remarkable improvement were 64.95% and 79.81% respectively. In the MTX group, the overall rates of effectiveness at 12 weeks and 24 weeks were 84.04% and 83.15% respectively; the rates of remarkable improvement were 56.81% and 75.28% respectively. According to intent-to-treat analysis, the ACR 20% response rates at 12 weeks and 24 weeks in the leflunomide group were 62.54% and 67.18% respectively, compared with 60.08% and 61.32% respectively in MTX group. No statistical differences were shown in the efficacy between the two groups (P > 0.05). The adverse events in the leflunomide group were gastrointestinal symptoms, skin rash, alopecia, nervous system symptoms, decreased leukocyte count, and elevation of alanine aminotransferase (ALT). Most of these side effects were mild and transient. The incidence of adverse events in the leflunomide group was 16.84%, significantly lower than that in MTX group (28.17%, P = 0.002). CONCLUSIONS: Leflunomide is effective in the treatment of RA with less adverse events than MTX. Its efficacy is similar to MTX, but the incidence of adverse events and the rate of withdrawal due to adverse events were lower in the leflunomide group than in MTX group.

[Cerebral ischemic events and anti-cancer therapy]. / Accidents ischémiques cérébraux et chimiothérapie anti-cancéreuse.

Antineoplastic agents have been associated with cerebral hemorrhage, infarction and cerebral venous thrombosis. Infarctions have been reported in association with L-asparaginase, cisplatinium, methotrexate and 5-fluro-uracil. The mechanisms by which antineoplastic agents may lead to stroke include endothelium toxicity and abnormalities of coagulation factors.

Mitomycin C in revision endoscopic dacryocystorhinostomy: a prospective randomized study.

BACKGROUND: Endoscopic dacryocystorhinostomy (EN-DCR) is an effective and safe procedure when treating saccal and postsaccal nasolacrimal duct obstruction. However, sometimes scarring of the rhinostomy site caused by fibrosis may occur, particularly in revision operations. The application of intraoperative mitomycin C (MMC), an antiproliferative agent, has been introduced as one possible technique to improve the outcome. We conducted a prospective, randomized study to evaluate if the use of MMC improves the success in endonasal revision DCR procedure. METHODS: Thirty revision EN-DCR procedures were performed during 2004-2010. The patients were randomized into two study groups, according to whether the intraoperative MMC was used or not. The technique of EN-DCR procedure in both groups was the same, but in the MMC group, at the end of the procedure a piece of tampon soaked in MMC (0.4 mg/mL) was placed into the rhinostoma for 5 minutes. No silicone stents were inserted. The surgical outcome at the 6-month follow-up visit was considered successful if the lacrimal sac irrigation succeeded and if the patients' symptoms were relieved. RESULTS: The success rate after revision EN-DCR with MMC was 93% and without MMC was 60%. The overall success rate was 77%. The difference between the two groups was not statistically significant (p = 0.08). The relief of the symptoms between groups in both the Nasolacrimal Duct Obstruction Symptom Score and ocular symptoms was statistically significant (p = 0.007 and p = 0.02, respectively). CONCLUSION: The results of our study indicate that the application of intraoperative mitomycin C may improve the outcome in revision EN-DCR.