Determination of mitomycin C in rat plasma by liquid chromatography-tandem mass spectrometry and its application for determining pharmacokinetics in rat.

To develop the liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for measuring mitomycin C in rat plasma, samples were processed using solid-phase extraction, with the internal standard being carbamazepine. A reversed phased C18 column was utilized for the LC-MS/MS study, and mobile phases consisting of 0.1 % formic acid in acetonitrile and water were injected into it at a rate of 0.3 mL/min. Multiple reaction monitoring in positive-ion mode with precursor-product ion pairs 335.3 â†’ 242.3 (mitomycin C) and 237.1 â†’ 194.1 (carbamazepine) was employed to quantify the compounds. The linear range in plasma was found to be 10-4000 ng/mL (r2 = 0.992). The inter-batch and intra-batch precision were <14.3 % (LLOQ: 14.7 %) and 13.4 % (LLOQ: 16.1 %), respectively. The recovery and the matrix effect of mitomycin C in plasma were 113 % and 111 %, respectively. Mitomycin C was stable under the conditions of this assay method. In the end, this approach proved effective in a pharmacokinetic investigation with the intravenous and oral administration of mitomycin C to rats.

Case report: Clinical features and management outcomes of isolated corneal intraepithelial neoplasia.

Purpose: To report clinical features and treatment outcome of three cases with isolated corneal intraepithelial neoplasia (CIN). Methods: This case series presents 3 patients with isolated CIN. Data collected included, presenting signs and symptoms including vision, anterior segment examination, medical and surgical outcomes and signs and symptoms at lost post-treatment visit. Results: Case 1 was a 45-year-old male who presented with an isolated grayish amoeboid corneal lesion which was excised with alcohol assisted epitheliectomy, he also received 6 cycles of topical mitomycin C (MMC) 0.02% and one injection of interferon alfa-2b with no recurrence during the 10-year follow-up period. Case 2 was 78-year-old male referred for a suspicious white corneal lesion which was completely excised, the patient also received 6 subconjunctival injections of interferon alpha-2b. However, the lesion recurred at 2.5-years post-treatment. Case 3 was a 63-year-old male patient who presented with an isolated corneal lesion that was excised using alcohol-assisted epitheliectomy, patient received four cycles of topical 5-fluorouracil with no recurrence at last follow-up visit at 6 months. Conclusion: Isolated corneal intraepithelial neoplasia (CIN) is a rare entity with few reported cases in the literature. In this case series, we report long and short-term management outcomes of combined surgical and medical therapy for isolated CIN.

Comparison of postoperative topical interferon-α2b versus intraoperative mitomycin C for pterygium recurrence prevention: a randomized clinical trial.

PURPOSE: To evaluate the effect of postoperative interferon-alpha 2b (IFN-α2b) ophthalmic drops versus intraoperative mitomycin-c (MMC) on preventing pterygium recurrence. METHODS: This prospective randomized clinical trial was conducted on patients who were candidates for pterygium surgery. A total of 75 patients were included in the study from December 2021 to December 2022, of which 64 patients (one eye each) were examined and analyzed based on the inclusion criteria. Then the patients were randomly assigned to control groups, intra-operative MMC (32 patients) and the intervention group, IFN-α2b drops after the operation (32 patients). All patients underwent pterygium surgery using the rotational conjunctival flap method. RESULTS: In terms of pterygium grading, 8 (12.5%), 25 (39.06%), and 31 (48.44%) eyes were in grades 1, 2, and 3, respectively. The average size of the pterygium was 3.6 ± 0.7 mm. The grade and size of pterygium had the same distribution in the two groups. There was no statistically significant difference between the two groups in the level of post-operative clinical inflammation. The present study showed no significant difference in complications between the two groups (p = 0.999). The recurrence rate in the control group was 9.4% (3 eyes), and 0% (no recurrence) in the intervention group (p = 0.119). CONCLUSIONS: interferon-alpha 2b group did not show a statistically significant difference in preventing pterygium recurrence compared to the mitomycin C group. The post-surgery administration of IFN-α 2b drops can effectively prevent pterygium recurrence with a comparable and even more compelling effect than MMC during surgery.

The Role of Mitomycin C in Intermediate-risk Non-muscle-invasive Bladder Cancer: A Systematic Review and Meta-analysis.

BACKGROUND AND OBJECTIVE: Intravesical mitomycin C (MMC) instillations are recommended to prevent recurrence of intermediate-risk non-muscle-invasive bladder cancer (IR-NMIBC); however, the optimal regimen and dose are uncertain. Our aim was to assess the effectiveness of adjuvant MMC and compare different MMC regimens in preventing recurrence. METHODS: We performed a comprehensive search in PubMed, Scopus, and Web of Science in November 2023 for studies investigating recurrence-free survival (RFS) among patients with IR-NMIBC who received adjuvant MMC. Prospective trials with different MMC regimens or other intravesical drugs as comparators were considered eligible. KEY FINDINGS AND LIMITATIONS: Overall, 14 studies were eligible for systematic review and 11 for meta-analysis of RFS. Estimates of 1-yr, 2-yr, and 5-yr RFS rates were 84% (95% confidence interval [CI] 79-89%), 75% (95% CI 68-82%), and 51% (95% CI 40-63%) for patients treated with MMC induction plus maintenance, and 88% (95% CI 83-94%), 78% (95% CI 67-89%), and 66% (95% CI 57-75%) for patients treated with bacillus Calmette-Guérin (BCG) maintenance, respectively. Estimates of 2-yr RFS rates for MMC maintenance regimens were 76% (95% CI 69-84%) for 40 mg MMC (2 studies) and 66% (95% CI 60-72%) for 30 mg MMC (4 studies). Among the studies included, BCG maintenance provided comparable 2-yr RFS to 40 mg MMC with maintenance (78% vs 76%). RFS did not differ by MMC maintenance duration (>1 yr vs 1 yr vs <1 yr). CONCLUSIONS AND CLINICAL IMPLICATIONS: MMC induction and maintenance regimens seem to provide short-term RFS rates equivalent to those for BCG maintenance in IR-NMIBC. For adjuvant induction and maintenance, 40 mg of MMC appears to be more effective in preventing recurrence than 30 mg. We did not observe an RFS benefit for longer maintenance regimens. PATIENT SUMMARY: For patients with intermediate-risk non-muscle-invasive bladder cancer, bladder treatments with a solution of a drug called mitomycin C (MMC) seem to be as effective as BCG (bacillus Calmette-Guérin) in preventing recurrence after tumor removal. Further trials are needed for stronger evidence on the best MMC dose and treatment time.

Critical appraisal of total gastrectomy plus total colectomy with hyperthermic intraperitoneal chemotherapy as a treatment for advanced pseudomyxoma peritonei.

BACKGROUND: The absolute requirement for a long-term favorable result with cytoreductive surgery for pseudomyxoma peritonei is a complete resection of all visible disease. A combination of parietal peritonectomy procedures and visceral resections is required for this to occur. The cytoreductive surgery is supplemented by hyperthermic intraperitoneal chemotherapy. METHODS: We searched our database and secured files for patients who required a total gastrectomy and a total colectomy to achieve a complete cytoreductive surgery. Survival of low-grade mucinous neoplasm (LAMN) and mucinous appendiceal adenocarcinoma (MACA) histologies were determined. Clinical and histologic variables were assessed for their impact on survival. RESULTS: Thirteen of 450 patients (2.9%) with LAMN histology and 14 of 186 patients (7.5%) with MACA histology had these visceral resections. Median survival of these 27 patients was 10 years. LAMN and MACA patients showed the same survival. For LAMN histology, this requirement for extensive visceral resection markedly reduced survival (p < 0.0001). For MACA, there was no adverse impact on survival (p = 0.4359). Class 4 adverse events caused reduced survival (p = 0.0014). CONCLUSIONS: A 10-year median survival accompanies total gastrectomy plus total colectomy for advanced pseudomyxoma peritonei. Systemic chemotherapy and class 4 adverse events reduced survival.

Cellular metabolomics study of the antitumor mechanism of Sijunzi decoction combined with mitomycin C.

Mitomycin C (MMC) has an antitumor effect and is considered as a broad-spectrum antibiotic. Sijunzi Decoction (SJZD), a well-known ancient Chinese prescription, is widely used in the treatment of cancer when combined with chemotherapy drugs. Studies have shown that SJZD can be combined with other drugs to enhance the therapeutic effect against cancer and inhibit the toxicity of chemotherapy drugs, but the specific mechanism is not clear. Thus, we hope to further explore the antitumor mechanism of combined SJZD and MMC. 3-(4,5-Dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide assay, flow cytometry, western blot, 1H NMR and HPLC-MS were used to study the mechanism at the cellular level. The results show that the combined administration can have a more significant effect on inhibiting the proliferation of cancer cells, promoting their apoptosis. Based on metabolomics, 38 biomarkers were found in the MMC group and 43 biomarkers were found in the combined administration group. Among them, 18 unique biomarkers were discovered in the combined administration group. Studies have shown that the antitumor mechanism of combined administration is related to amino acid metabolism, energy metabolism, lipid metabolism and nucleotide metabolism, among which amino acid metabolism is the most important. In addition, SJZD achieves the effect of toxin reduction and efficiency enhancement by improving the body's immunity and improving the oxidative stress environment.

Critical reappraisal of prognostic indicators for 949 mucinous appendiceal neoplasm patients.

BACKGROUND AND OBJECTIVES: The standard of care for treatment of an appendiceal mucinous neoplasm with peritoneal dissemination is cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC). These two treatments are combined in the operating room. A crucial requirement for benefit long-term is proper patient selection. Clinical and histopathologic prognostic indicators are used, along with the patient's fitness for surgery, to select patients to receive CRS and HIPEC. METHODS: This study seeks to identify the reliable prognostic indicators for four different groups of patients. They are (1) the low-grade appendiceal mucinous neoplasms (LAMN) with a complete CRS, (2) the mucinous appendiceal adenocarcinomas (MACA) with complete CRS, (3) MACA with lymph node metastases (MACA-LN) with complete CRS, and (4) all histologic subtypes with incomplete cytoreduction. The prognostic indicators were evaluated for their impact on overall survival in these four groups of patients. RESULTS: The completeness of cytoreduction (CC) score statistically significantly showed survival differences in all three histologic subtypes. The peritoneal cancer index (PCI) showed significance with LAMN and MACA-LN but not with MACA and not with incomplete CRS. The prior surgical score (PSS) was a prognostic indicator that predicted the outcome with LAMN, MACA-LN, and incomplete CRS patients but not with the MACA group. Patients who were symptomatic or who had extensive systemic chemotherapy before CRS had a significantly reduced survival. CONCLUSION: The utility of prognostic indicators varied greatly within our four different groups of appendiceal mucinous neoplasms. CC score was always a reliable prognosticator. Surprisingly, PCI was not.

Efficacy of adjuvant mitomycin-C and triamcinolone-impregnated nasal packing for endoscopic dacryocystorhinostomy.

AIM: To compare the success rate and complications of adjuvant use of mitomycin C and triamcinolone-impregnated biodegradable nasal packing (TABP) in endoscopic dacryocystorhinostomy (DCR). And to evaluate the efficacy of combining intraoperative mitomycin C and TABP for endoscopic DCR. METHODS: A total of 198 eyes of 148 patients who underwent endoscopic DCR for acquired nasolacrimal duct obstruction were retrospectively analysed. The patients were randomly divided into three groups: Group A included patients treated without intraoperative mitomycin C but with TABP, Group B included patients treated without triamcinolone but with intraoperative mitomycin C and normal saline-impregnated nasal packing, and Group C included patients treated with intraoperative mitomycin C and TABP. RESULTS: The results revealed no significant difference in the overall success rates between Groups A (86.8%) and B (89.2%; P=0.377). However, Group C (97.5%) showed a significantly higher overall success rate than Groups A and B. The incidence of granulomas was significantly lower in group C (5%) than in Groups A (20.8%) and B (15.2%; P=0.009). Other complications, such as crust, synechiae, and revision surgery, did not differ significantly among the three groups. CONCLUSION: The combination of intraoperative mitomycin C and TABP effectively prevents granulomas and enhances surgical success rate. Additionally, there is no statistically significant difference observed between the use of mitomycin C or TABP alone.

Effect of mitomycin C on the corneal endothelial cells of Saudi patients with myopia after transepithelial photorefractive keratectomy: a two-armed cohort study.

AIM: To study the effect of mitomycin C (MMC) applied during transepithelial photorefractive keratectomy (TPRK) on the corneal endothelium one week (W1) and three months (M3) after surgery and its determinants. METHODS: In this two-armed cohort study conducted in 2022, eyes treated with MMC during TPRK (group 1) were compared with eyes not treated with MMC (group 2). The corneal endothelial cell (EC) count, EC density (ECD; cells/mm2), average (µm2), standard deviation (µm2), coefficient of variation (CV%), ECmax, ECmin, and EC percentage of hexagonality were estimated at W1 and M3. The postoperative changes in the EC count in the two groups were compared and correlated with the other independent variables. RESULTS: Group 1 had 26 eyes, and group 2 had 78 eyes. All TPRK indices were significantly higher for the eyes in group 1 than for those in group 2. The MMC usage was not a significant predictor of the change in ECD (P=0.644), change in CV (P=0.374), and change in the percentage of hexagonality of EC (P=0.164) at W1. However, the use of MMC was a significant predictor of changes in CV (P=0.014) and the change in the percentage of hexagonality of EC (P=0.039) at M3. The duration of laser exposure and the size of the optical zone influenced the correlation of MMC use with the changes in EC indices, postoperatively. CONCLUSION: The use of MMC doesn't affect ECD, CV, and percentage of hexagonality at W1 if other surgical indices are considered. At M3 after operating myopic eyes by TPRK, MMC significantly influence the CV and percentage of hexagonality. The duration of the laser application and the size of the optical zone should be considered when determining the effect of MMC on the EC indices.

Safety and Efficacy of Immediate Hyperthermic Intravesical Chemotherapy Following Transurethral Resection of Bladder Tumour (I-HIVEC).

The recurrence rate following endoscopic treatment of non-muscle-invasive bladder cancer (NMIBC) remains high. Standard treatment includes intravesical instillation of chemotoxic agents such as mitomycin C (MMC) to reduce recurrence. It is postulated that upfront administration of hyperthermic intravesical MMC (HIVEC) immediately after transurethral resection of bladder tumour (TURBT) may enhance its efficacy, but evidence from human trials is scant. This pilot study explored the safety of immediate intravesical MMC instillation following TURBT using a conductive HIVEC system (Combat BRS). Patients diagnosed with papillary bladder tumours scheduled for TURBT were recruited. Among 29 patients treated with HIVEC, there was minimal additional postoperative morbidity. The majority (79.3%) were discharged after a hospital stay of 1 d, and no patient required bladder irrigation. There were six grade I-II adverse events (20.7%) and one grade III event (3.4%). No recurrences were observed within 3 mo, and the 12-mo recurrence rate was 4.5%. The study findings demonstrate that immediate HIVEC MMC instillation following TURBT is safe. Further research is needed to assess long-term efficacy in comparison to standard cold MMC. PATIENT SUMMARY: Non-muscle-invasive bladder cancer is treated with tumour removal via a telescope inserted into the bladder through the urethra (called TURBT). We tested the safety of treating the bladder with a warm solution of a chemotherapy drug (mitomycin C) immediately after TURBT, as this may prevent tumour recurrence. The treatment was safe and well tolerated. Further trials are needed with more patients and longer follow-up to confirm the results.

Exposure of Bladder Cancer Cells to Blue Light (λ = 453 nm) in the Presence of Riboflavin Synergistically Enhances the Cytotoxic Efficiency of Gemcitabine.

Non-muscle invasive bladder cancer is a common tumour in men and women. In case of resistance to the standard therapeutic agents, gemcitabine can be used as off-label instillation therapy into the bladder. To reduce potential side effects, continuous efforts are made to optimise the therapeutic potential of drugs, thereby reducing the effective dose and consequently the pharmacological burden of the medication. We recently demonstrated that it is possible to significantly increase the therapeutic efficacy of mitomycin C against a bladder carcinoma cell line by exposure to non-toxic doses of blue light (453 nm). In the present study, we investigated whether the therapeutically supportive effect of blue light can be further enhanced by the additional use of the wavelength-specific photosensitiser riboflavin. We found that the gemcitabine-induced cytotoxicity of bladder cancer cell lines (BFTC-905, SW-1710, RT-112) was significantly enhanced by non-toxic doses of blue light in the presence of riboflavin. Enhanced cytotoxicity correlated with decreased levels of mitochondrial ATP synthesis and increased lipid peroxidation was most likely the result of increased oxidative stress. Due to these properties, blue light in combination with riboflavin could represent an effective therapy option with few side effects and increase the success of local treatment of bladder cancer, whereby the dose of the chemotherapeutic agent used and thus the chemical load could be significantly reduced with similar or improved therapeutic success.

[Pharmacological prevention of fibrosis in dacryosurgery]. / Medikamentoznaya profilaktika fibrotizatsii v dakriokhirurgii.

Chronic inflammatory process in the lacrimal drainage system is the main etiological factor leading to dacryostenosis and consequent obliteration - partial and total nasolacrimal duct obstruction. Prevention of this process is an urgent problem in dacryology. Currently, there is very little research on the development and use of conservative methods for treating dacryostenosis using anti-inflammatory, as well as anti-fibrotic drugs. In this regard, the main method of treating lacrimal drainage obstruction is dacryocystorhinostomy. However, the problem of recurrence after this operation has not been resolved. The causes of recurrence can be cicatricial healing of dacryocystorhinostomy ostium, canalicular obstruction, formation of granulations and synechiae in its area. Surgical methods of recurrence prevention are associated with possible complications, and there is conflicting data on the feasibility of their use. Based on this, the development of pharmacological methods for the prevention of fibrosis in dacryology is promising, among which the antitumor antibiotic Mitomycin C is the most studied. However, there are no specific scientifically substantiated recommendations for the use of this drug, and the data on its effectiveness vary. This has prompted researchers to look for and study alternative anti-fibrotic agents, such as antitumor drugs, glucocorticoids, hyaluronic acid, small molecule, biological, immunological and genetically engineered drugs, as well as nanoparticles. This review presents the current data on the efficacy and prospects of the use of these drugs in dacryology.

Cellularity of mucus is a prognostic variable in low-grade appendiceal mucinous neoplasms.

For peritoneal metastases from a primary appendiceal mucinous neoplasm to exist, the thin wall of the appendix must perforate to allow mucus or mucus plus tumor cells to gain access to the peritoneal spaces. The proportion of specimens containing tumor cells within mucus as compared to mucus only outside the appendix may have prognostic significance. The histopathology of tumor masses was determined from the specimens resected at the cytoreductive surgery (CRS). The presence versus absence of tumor cells in mucus and the proportion of specimens with tumor cells was determined and correlated with the overall survival of these patients. In 418 patients with a complete cytoreduction for a low-grade appendiceal mucinous neoplasm (LAMN), the cellularity of all resected specimens was determined. The hazard ratio of overall survival of patients whose specimens had no cells as compared to specimens with cells in mucus by histology was 4.41 (1.61, 12.1) (p = 0.0039). If overall survival of patients with all specimens without tumor cells was compared to patients with specimens with 1-99 % tumor and compared to patients with 100 % of specimens with tumor cells, the hazard ratios were 4.3 (1.34, 13.8) (p = 0.0143) and 9.62 (2.93, 31.6) (p = 0.0002), respectively. The cellularity of mucus within the specimens removed by a complete CRS has strong prognostic implications in LAMN patients. LAMN with acellular specimens (LAMNa) as compared to LAMN with tumor cells in specimens (LAMNb) should be staged as different histologic subtypes of mucinous appendiceal neoplasms.

The effect of adjuvant Mitomycin C during vitrectomy on functional and anatomical outcomes in patients with severe diabetic tractional retinal detachment.

PURPOSE: To evaluate the effect of adjuvant Mitomycin C (MMC) use on the anatomical and functional success of vitreoretinal surgery (VRS) in severe diabetic tractional retinal detachment (dTRD) patients. METHODS: A retrospective analysis of consecutive patients undergoing VRS due to severe dTRD was conducted. Patients were categorized into those who received 20 µg/0.1 mL MMC via MMC sandwich method (Group 1) and those who did not (Group 2). Demographics, surgical characteristics, visual outcomes, and complications that may related to MMC were analyzed. RESULTS: A total of 25 eyes were included, 13 in Group 1 and 12 in Group 2. No statistical difference was observed in baseline characteristics between the groups. The mean best-corrected visual acuity was 1.90 ± 0.43 logMAR and 1.93 ± 0.41 logMAR preoperatively and 1.60 ± 0.78 logMAR and 1.56 ± 0.78 logMAR postoperatively in Groups 1 and 2, respectively (p = 0.154). The postoperative mean intraocular pressure was 16.23 ± 2.55 mmHg and 13.08 ± 4.94 mmHg in Groups 1 and 2, respectively (p = 0.225). The rate of re-surgery was significantly lower in Group 1 (0% vs. 41.7% in Group 2, p = 0.015). Retina was attached in all patients at the last visit. No MMC-related complication was recorded. CONCLUSION: Intraoperative adjuvant MMC application for severe dTRD significantly reduces re-surgery rates with good anatomical and functional outcomes safely.

Safety and oncological outcome of early intraoperative intravesicle mitomycin C vs. deferred instillation in patients receiving robot-assisted radical nephroureterectomy.

Introduction: Radical nephroureterectomy with concurrent bladder cuff excision (RNUBCE) is the gold standard surgical approach for high-risk primary upper tract urothelial carcinoma (UTUC). Given the notably high incidence of bladder tumor recurrence following this procedure, this study aimed to evaluate the effect and safety of intraoperative mitomycin-C (MMC) instillation vs. deferred instillation on overall oncological outcomes following robot-assisted RNUBCE. Methods: This is a retrospective chart review study. Patients with non-invasive (N0, not T3/T4) UTUC who underwent robotic RNUBCE combined an intraoperative MMC instillation or a deferred MMC instillation after surgery at a medical center in Taiwan between November 2013 and June 2020 were eligible for inclusion. Patients with prior bladder UC, carcinomas of other origins, received neoadjuvant chemotherapy, and had undergone kidney transplantation were excluded. All surgeries were executed by a single surgical team under the guidance of the same surgeon. The primary outcomes was the risk of bladder tumor recurrence between patients received intraoperative (IO) vs. deferred MMC instillation postoperatively (PO) during one-year follow-up. The secondary outcome was postoperative adverse events assessed by the Clavien-Dindo classification. Univariate and multivariable Cox regression analyses were performed to determine the associations between study variables and the outcomes. Results: A total of 54 patients were included in the analysis. 12 (22.2%) patients experienced a bladder tumor recurrence during follow-up (IO: 7.7%, PO: 35.7%, p < 0.021). After adjustment in the multivariable, intraoperative MMC instillation was significantly associated with lower risk of bladder recurrence [adjusted hazard ratio (aHR) = 0.15, 95% CI: 0.03-0.81, p = 0.028]. No MMC-related Clavien-Dindo Grade III-IV adverse events were found in either group. Conclusion: IIntraoperative MMC instillation is safe and associated with a lower bladder tumor recurrence risk in patients undergoing robotic RNUBCE for UTUC than deferred instillation. Future large, prospective studies are still warranted to confirm the findings.

Chromosome-specific induction of micronuclei and chromosomal aberrations by mitomycin C: Involvement of human chromosomes 9, 1 and 16.

Cytogenetic studies have shown that human chromosomes 1, 9, and 16, with a large heterochromatic region of highly methylated classical satellite DNA, are prone to induction of chromatid breaks and interchanges by mitomycin C (MMC). A couple of studies have indicated that material from chromosome 9, and possibly also from chromosomes 1 and 16, are preferentially micronucleated by MMC. Here, we further examined the chromosome-specific induction of micronuclei (MN; with and without cytochalasin B) and chromosomal aberrations (CAs) by MMC. Cultures of isolated human lymphocytes from two male donors were treated (at 48 h of culture, for 24 h) with MMC (500 ng/ml), and the induced MN were examined by a pancentromeric DNA probe and paint probe for chromosome 9, and by paint probes for chromosomes 1 and 16. MMC increased the total frequency of MN by 6-8-fold but the frequency of chromosome 9 -positive (9+) MN by 29-30-fold and the frequency of chromosome 1 -positive (1+) MN and chromosome 16 -positive (16+) MN by 12-16-fold and 10-17-fold, respectively. After treatment with MMC, 34-47 % of all MN were 9+, 17-20 % 1+, and 3-4 % 16+. The majority (94-96 %) of the 9+ MN contained no centromere and thus harboured acentric fragments. When MMC-induced CAs aberrations were characterized by using the pancentromeric DNA probe and probes for the classical satellite region and long- and short- arm telomeres of chromosome 9, a high proportion of chromosomal breaks (31 %) and interchanges (41 %) concerned chromosome 9. In 83 % of cases, the breakpoint in chromosome 9 was just below the region (9cen-q12) labelled by the classical satellite probe. Our results indicate that MMC specifically induces MN harbouring fragments of chromosome 9, 1, and 16. CAs of chromosome 9 are highly overrepresented in metaphases of MMC-treated lymphocytes. The preferential breakpoint is below the region 9q12.

Mitomycin C and its analog trigger cytotoxicity in MCF-7 and K562 cancer cells through the regulation of RAS and MAPK/ERK pathways.

Mitomycin C (MC) is an anti-cancer drug which functions by forming interstrand crosslinks (ICLs) between opposing DNA strands. MC analog, 10-decarbamoyl mitomycin C (DMC), unlike MC, has stronger cytotoxic effects on cancer cells with TP53 mutation. We previously demonstrated that MC/DMC could activate p21WAF1/CIP1 in MCF-7 (TP53-proficient) and K562 (TP53 deficient) cells in a TP53-independent mode. We also found that MC/DMC regulate AKT activation in a TP53-dependent manner and that AKT deactivation is not associated with the activation of p21WAF1/CIP1 in response to MC/DMC treatment. RAS proteins are known players in the upstream mediated signaling of p21WAF1/CIP1 activation that leads to control of cell proliferation and cell death. Thus, this prompted us to investigate the effect of both drugs on the expression of RAS proteins and regulation of the MAPK/ERK signaling pathways in MCF-7 and K562 cancer cells. To accomplish this goal, we performed comparative label free proteomics profiling coupled to bioinformatics/complementary phosphoprotein arrays and Western blot validations of key signaling molecules. The MAPK/ERK pathway exhibited an overall downregulation upon MC/DMC treatment in MCF-7 cells but only DMC exhibited a mild downregulation of that same pathway in TP53 mutant K562 cells. Furthermore, treatment of MCF-7 and K562 cell lines with oligonucleotides containing the interstrand crosslinks (ICLs) formed by MC or DMC shows that both ICLs had a stronger effect on the downregulation of RAS protein expression in mutant TP53 K562 cells. We discuss the implication of this regulation of the MAPK/ERK pathway in relation to cellular TP53 status.

Comparing Outcomes of Tube Versus Trabeculectomy Among Patients With Angle-closure Glaucoma.

PURPOSE: Compare outcomes of tube shunt surgery (Tube) and trabeculectomy with mitomycin C (Trab-MMC) in patients with angle-closure glaucoma (ACG). DESIGN: Retrospective nonrandomized comparative study. PARTICIPANTS: A total of 80 eyes from 80 patients with ACG who underwent either Tube (N = 50) or Trab-MMC (N = 30) between January 2015 and January 2022 at Massachusetts Eye and Ear. METHODS: Reviewed and analyzed 390 visits from patient charts. MAIN OUTCOME MEASURES: Kaplan-Meier (KM) success rates, intraocular pressure (IOP), medication burden, best-corrected visual acuity (BCVA), adjusted hazard ratios (HRs), and complications. RESULTS: Baseline demographics were similar between both groups, except for a higher proportion of patients with pseudophakia and prior incisional ocular surgery in the Tube group. The Trab-MMC procedure had significantly higher KM complete success (CS) rates than the Tube procedure, but similar qualified success (QS) rates. Under QS, the cumulative probability of survival was 87% in the Tube group and 83% in the Trab-MMC group at year 1 (P = 0.77), and 75% in the Tube group and 58% in the Trab-MMC group at year 2 (P = 0.14). Under CS, the cumulative probability of survival was 13% in the Tube group and 59% in the Trab-MMC group at year 1 (P < 0.001), and 11% in the Tube group and 41% in the Trab-MMC group at year 2 (P < 0.001). Both Tube and Trab-MMC procedures resulted in significant patterns of IOP and medication reduction from baseline up to 2 years with mean IOP reduced to 12.6 ± 5.9 mmHg on 2.8 ± 1.4 medications after Tube and 12.1 ± 6.6 mmHg on 2.4 ± 1.7 medications after Trab-MMC. Patients who underwent Trab-MMC required less IOP-lowering medications at every follow-up visit up to year 1, but a similar number at year 2. No significant differences were found in IOP reduction, BCVA, or complication rates between groups. CONCLUSIONS: We demonstrate that Trab-MMC confers similar IOP reduction and QS rates to Tube placement in patients with ACG. Trab-MMC, however, demonstrated greater medication burden reduction up to 1 year, and more favorable CS rates up to 2 years, while still maintaining similar complication rates to Tube. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Using a Novel, Subconjunctival, Sustained-Release Mitomycin C Formulation in a Rabbit Model of Filtration Surgery with Gel Stent Implantation.

Purpose: To investigate gel stent implantation with and without intraoperative sustained-release mitomycin C (MMC SR) in a rabbit model for gel stent implantation, and to examine aqueous humor outflow (AHO) postimplantation. Methods: Four groups of rabbits were included. Group 1 was untreated (control). Groups 2, 3, and 4 received the gel stent without MMC, with MMC solution (subconjunctival injection), and with MMC SR (subconjunctival injection), respectively. Intraocular pressure (IOP) and AHO were assessed via tonometry and indocyanine green-based angiography, respectively. The main efficacy measure was change in IOP from baseline. Results: Following gel stent implantation, Groups 2, 3, and 4 maintained ≥20% IOP reduction (response) for a median duration of 1 week, 6.5 weeks, and 30 weeks, respectively. Angiography showed normal aqueous humor drainage (Group 1) beginning at the perilimbal trabecular plexus and continuing posteriorly to episcleral outflow vessels. Following implantation, drainage occurred preferentially and directly into the subconjunctival bleb. Conclusions: Gel stent implantation with MMC SR was most effective in achieving sustained, long-term IOP reduction in the rabbit model, compared with implantation with or without MMC solution. Bleb presence and the postimplantation aqueous angiography results indicated redirection of the AHO to the subconjunctival vasculature and presumed lymphatics, suggesting efficient glaucoma filtration to lower IOP in this model. This rabbit model and aqueous angiography may help refine understanding of the mechanism of action of minimally invasive glaucoma surgeries and ultimately translate to improved surgical devices and procedures for patients with glaucoma.