Penicillin- and Cephalosporin-Resistant Pneumococcal Meningitis: Treatment in the Real World and in Guidelines.

To report on the therapy used for penicillin- and cephalosporin-resistant pneumococcal meningitis, we conducted an observational cohort study of patients admitted to our hospital with pneumococcal meningitis between 1977 and 2018. According to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) recommendations, we defined pneumococci as susceptible and resistant to penicillin with MIC values of ≤0.06 mg/L and > 0.06 mg/L, respectively; the corresponding values for cefotaxime (CTX) were ≤0.5 mg/L and >0.5 mg/L. We treated 363 episodes of pneumococcal meningitis during the study period. Of these, 24 had no viable strain, leaving 339 episodes with a known MIC for inclusion. Penicillin-susceptible strains accounted for 246 episodes (73%), penicillin-resistant strains for 93 (27%), CTX susceptible for 58, and CTX resistant for 35. Nine patients failed or relapsed and 69 died (20%), of whom 22% were among susceptible cases and 17% were among resistant cases. During the dexamethasone period, mortality was equal (12%) in both susceptible and resistant cases. High-dose CTX (300 mg/Kg/day) helped to treat failed or relapsed cases and protected against failure when used as empirical therapy (P = 0.02), even in CTX-resistant cases. High-dose CTX is a good empirical therapy option for pneumococcal meningitis in the presence of a high prevalence of penicillin and cephalosporin resistance, effectively treating pneumococcal strains with MICs up to 2 mg/L for either penicillin or CTX.

Metformin alters therapeutic effects in the BALB/c tumor therapy model.

BACKGROUND: Despite considerable medical proceedings, cancer is still a leading cause of death. Major problems for tumor therapy are chemoresistance as well as toxic side effects. In recent years, the additional treatment with the antidiabetic drug metformin during chemotherapy showed promising results in some cases. The aim of this study was to develop an in vitro tumor therapy model in order to further investigate the potential of a combined chemotherapy with metformin. METHODS: Cytotoxic effects of a combined treatment on BALB/c fibroblasts were proven by the resazurin assay. Based on the BALB/c cell transformation assay, the BALB/c tumor therapy model was established successfully with four different and widely used chemotherapeutics from different categories. Namely, Doxorubicin as a type-II isomerase inhibitor, Docetaxel as a spindle toxin, Mitomycin C as an alkylating agent and 5-Fluorouracil as an antimetabolite. Moreover, glucose consumption in the medium supernatant was measured and protein expressions were determined by Western Blotting. RESULTS: Initial tests for the combined treatment with metformin indicated unexpected results as metformin could partly mitigate the cytotoxic effects of the chemotherapeutic agents. These results were further confirmed as metformin induced resistance to some of the drugs when applied simultaneously in the tumor therapy model. Mechanistically, an increased glucose consumption was observed in non-transformed cells as well as in the mixed population of malignant transformed cell foci and non-transformed monolayer cells, suggesting that metformin could also increase glucose consumption in transformed cells. CONCLUSION: In conclusion, this study suggests a cautious use of metformin during chemotherapy. Moreover, the BALB/c tumor therapy model offers a potent tool for further mechanistic studies of drug-drug interactions during cancer therapy.

An evaluation of UGN-101, a sustained-release hydrogel polymer-based formulation containing mitomycin-C, for the treatment of upper urothelial carcinomas.

INTRODUCTION: The treatment of low-grade upper tract urothelial carcinomas (UTUCs) after either surgery, or nephron-sparing techniques remains an unmet need in Genitourinary (GU) Oncology. UGN-101 is a novel drug in development for the treatment of UTUCs; it is composed of a sustained-release hydrogel polymer-based formulation containing the antitumor antibiotic mitomycin-C (MM-C); cold UGN-101 is liquid, but at body temperature, it becomes a gel, and thus, when administered through a ureteral catheter, it sticks to the upper tract urothelium, slowly releasing MM-C. AREAS COVERED: Here, the authors review the preclinical rationale for the development of UGN-101, as well as presently available clinical results for the treatment of low-grade UTUCs. EXPERT OPINION: The positive results of the recently completed OLYMPUS trial suggest the feasibility, activity (59% of complete responses, with just 6 of these complete responders on follow-up who recurred), and safety (68% of patients experiencing mild to moderate urinary adverse events) of UGN-101 instillations into the upper urinary tract. Our expectations are that UGN-101 will soon become a standard of treatment for low-grade UTUC at risk of relapse after either surgery, or nephron-sparing techniques.

The Temperature-Dependent Effectiveness of Platinum-Based Drugs Mitomycin-C and 5-FU during Hyperthermic Intraperitoneal Chemotherapy (HIPEC) in Colorectal Cancer Cell Lines.

Cytoreductive surgery (CRS) followed by hyperthermic intraperitoneal chemotherapy (HIPEC) is a treatment with curative intent for peritoneal metastasis of colorectal cancer (CRC). Currently, there is no standardized HIPEC protocol: choice of drug, perfusate temperature, and duration of treatment vary per institute. We investigated the temperature-dependent effectiveness of drugs often used in HIPEC. METHODS: The effect of temperature on drug uptake, DNA damage, apoptosis, cell cycle distribution, and cell growth were assessed using the temperature-dependent IC50 and Thermal Enhancement Ratio (TER) values of the chemotherapeutic drugs cisplatin, oxaliplatin, carboplatin, mitomycin-C (MMC), and 5-fluorouracil (5-FU) on 2D and 3D CRC cell cultures at clinically relevant hyperthermic conditions (38-43 °C/60 min). RESULTS: Hyperthermia alone decreased cell viability and clonogenicity of all cell lines. Treatment with platinum-based drugs and MMC resulted in G2-arrest. Platinum-based drugs display a temperature-dependent synergy with heat, with increased drug uptake, DNA damage, and apoptosis at elevated temperatures. Apoptotic levels increased after treatment with MMC or 5-FU, without a synergy with heat. CONCLUSION: Our in vitro results demonstrate that a 60-min exposure of platinum-based drugs and MMC are effective in treating 2D and 3D CRC cell cultures, where platinum-based drugs require hyperthermia (>41 °C) to augment effectivity, suggesting that they are, in principle, suitable for HIPEC.

Antigenotoxic, Anti-photogenotoxic, and Antioxidant Properties of Polyscias filicifolia Shoots Cultivated In Vitro.

Traditional medicinal plants are an important source of active compounds with potential antimutagenic activity. Polyscias filicifolia Bailey (Araliaceae) is a South Asian traditional herb used as an adaptogenic and cardiac drug. Extracts of P. filicifolia contain a wide range of biologically active compounds like phenolic acids and triterpenoid saponins. In the present study. antigenotoxic potential of three naturally occurring phenolic acids and extracts of P. filicifolia growing in vitro with the addition of elicitors was evaluated against direct (4-nitroquinoline-N-oxide (4NQO) and mitomycin C (MMC)) and indirect mutagens (2-aminoanthracene (2AA)). The evaluation was made using a bacterial umu-test. Moreover, the ability to prevent photogenotoxicity induced by chlorpromazine (CPZ) under UVA irradiation was measured. The phytochemical profiling of examined extracts revealed the presence of numerous compounds with the prevelance of chlorogenic, caffeic, and ferulic acid derivatives; however, saponin fractions were also determined. The antioxidant potential of extracts strictly correlated with their composition. The tested extracts exhibited high antigenotoxic activity if the assay was performed with 2AA and metabolic activation. Moreover, the extracts slightly decreased the MMC-induced genotoxicity. However, an increase of the genotoxic effect was observed in the assay performed with 4NQO. In addition, photo-antigenotoxic activity was observed. In our study, phenolic acids exhibited lower activity than the extracts.

Novel Analytical Platform For Robust Identification of Cell Migration Inhibitors.

Wound healing assay is a simple and cost-effective in vitro assay for assessing therapeutic impacts on cell migration. Its key limitation is the possible confoundment by other cellular phenotypes, causing misinterpretation of the experimental outcome. In this study, we attempted to address this problem by developing a simple analytical approach for scoring therapeutic influences on both cell migration and cell death, while normalizing the influence of cell growth using Mitomycin C pre-treatment. By carefully mapping the relationship between cell death and wound closure rate, contribution of cell death and cell migration on the observed wound closure delay can be quantitatively separated at all drug dosing. We showed that both intrinsic cell motility difference and extrinsic factors such as cell seeding density can significantly affect final interpretation of therapeutic impacts on cellular phenotypes. Such discrepancy can be rectified by using the actual wound closure time of each treatment condition for the calculation of phenotypic scores. Finally, we demonstrated a screen for strong pharmaceutical inhibitors of cell migration in cholangiocarcinoma cell lines. Our approach enables accurate scoring of both migrastatic and cytotoxic effects, and can be easily implemented for high-throughput drug screening.

Mitomycin C induces fibroblast apoptosis and reduces intra-articular scar adhesion by regulating miR-21 and its target Programmed cell death 4.

Previous studies have shown that mitomycin C (MMC) can prevent scar adhesion after joint surgery, but the specific mechanism underlying this effect remains unclear. The purpose of this study was to explore the specific mechanism by which MMC promotes fibroblast apoptosis and prevents joint adhesion. The effect of MMC on fibroblasts was assessed using cell counting kit-8 (CCK-8) assays, western blotting, and TUNEL staining. We used qRT-PCR to measure the expression of miR-21 in fibroblasts treated with MMC. Luciferase activity assays were used to determine the relationships between miR-21 and Programmed cell death 4 (PDCD4). The effects of miR-21 and PDCD4 on fibroblast apoptosis were assessed using flow cytometry and western blotting. HE staining was used to determine the role of miR-21 in scar tissue formation in a model of joint adhesion. The results showed that MMC induced apoptosis of fibroblasts and decreased the expression of miR-21. Moreover, miR-21 down-regulation also induced apoptosis of fibroblasts. PDCD4 was confirmed to be a direct target of miR-21 by luciferase activity assay. The results from the animal model indicated that miR-21 attenuated the effect of MMC on reducing the number of fibroblasts. Our study shows that MMC can induce fibroblast apoptosis and prevent joint adhesion by regulating the expression of miR-21 and its target PDCD4.

Genotoxic and Genoprotective Potential of Black Mulberry (Morus nigra) Fruit.

Black Mulberry (Morus nigra L.) belongs to Moraceae family. The present study evaluated the possible genotoxic and/or protective activities of black mulberry fruit juice (BMFJ), in vitro, using mitomycin C (MMC) as a positive control, by chromosomal aberrations and micronucleus assays. Human lymphocytes were treated with BMFJ concentrations alone (1/1, 1/2, 1/4, 1/8 dilutions), pretreatment (49h) (0.20 µg/ml MMC+ 1/1 BMFJ, 0.20 µg/ml MMC+1/2 diluted BMFJ, 0.20 µg/ml MMC+1/4 diluted BMFJ, 0.20 µg/ml MMC+1/8 diluted BMFJ) and simultaneous-treatment (48h) (0.20 µg/ml MMC+ 1/1 BMFJ, 0.20 µg/ml MMC+1/2 diluted BMFJ, 0.20 µg/ml MMC+1/4 diluted BMFJ, 0.20 µg/ml MMC+1/8 diluted BMFJ). The in vitro results demonstrated that BMFJ showed no genotoxicity, but it significantly decreased chromosomal aberration and micronucleus frequency induced by MMC. Our results showed that all concentrations of BMFJ revealed no genotoxicity but protective activity against genomic changes induced by anti-tumor agent MMC in human lymphocytes. Protective effects of BMFJ on MMC induced chromosomal damages most probably due to its free radical scavenging activity.

Assessment of nephrotoxicity associated with combined cisplatin and mitomycin C usage in laparoscopic hyperthermic intraperitoneal chemotherapy.

BACKGROUND: Laparoscopic hyperthermic intraperitoneal chemotherapy (HIPEC) has been used to treat various peritoneal malignancies. Cisplatin and mitomycin C (MMC) are agents commonly used in these procedures and, individually, each has been associated with acute kidney injury (AKI). There is limited literature on the complications associated with the use of both agents in HIPEC. Therefore, we sought to determine the incidence of nephrotoxicity and electrolyte abnormalities in patients undergoing laparoscopic HIPEC using this chemotherapeutic combination. METHODS: We retrospectively evaluated patients undergoing laparoscopic HIPEC for gastric or gastroesophageal adenocarcinoma using both cisplatin and MMC. Sodium thiosulfate was given for renal protection and kidney function was evaluated daily up to postoperative day #2. Details regarding patient characteristics, selection criteria, chemotherapeutic regimen, perioperative lab values and anesthetic management were collected. RESULTS: Twenty-three patients underwent 31 laparoscopic HIPEC procedures. Fifteen (65%) were male and the median age was 57 (range 21-75). Thirteen procedures were associated with an elevation in creatinine (Cr) with the median difference between POD#2 and baseline being 0.09 mg/dL (range 0-0.43). The glomerular filtration rate median difference between POD#2 and baseline was -17 mL/min/1.37 sq. m (range -42 to 11). No cases demonstrated AKI, defined as a 50% increase in Cr levels above baseline. An 84% incidence of postoperative hypophosphatemia (26/31) and 94% incidence of postoperative hypocalcemia (29/31) was observed. CONCLUSION: The laparoscopic approach to HIPEC using both cisplatin and MMC in our cohort was not associated with an increased incidence of AKI. The incidence of hypophosphatemia and hypocalcemia needs further evaluation to determine the exact etiology. Precis' statement: We retrospectively studied the association of AKI with the combined use of cisplatin and MMC in laparoscopic HIPEC.

Evaluation of Antitumor Activity and Hepatoprotective Effect of Mitomycin C Solubilized in Chamomile Oil Nanoemulsion.

PURPOSE: The present study aimed to investigate the antitumor activity and hepatoprotective effect of the MTC, when combined with CHAM oil nanoemulsion (NE), (CHAM-MTC) on the tumor growth. MATERIALS/METHODS: The in vitro study assessed the antineoplastic effect of CHAM-MTC on the MCF-7 breast cancer cells while the in vivo therapeutic effectiveness and toxicities of CHAM-MTC were evaluated in Ehrlich Ascites Carcinoma (EAC) bearing mice. One hundred female Swiss albino mice, divided equally into non-EAC group (negative control), untreated EAC group (positive control) and three EAC groups received once intraperitoneal injection of 0.2ml CHAM-NE, 0.2ml Normal Saline (NS) contained MTC (1mg/kg) and 0.2ml CHAM-NE mixed with MTC (1mg/kg), respectively. RESULTS: The in vitro results indicated that CHAM-NE could potentiate the effect of MTC in sub-effective concentrations since the half-maximal inhibitory concentration (IC50) was reduced by a factor of 21.94 when compared to the MTC-NS. The in vivo study revealed that mice treated with CHAM-MTC showed a significant increase in the median survival time (MST= 37 days) when compared to the MTC-NS treated group (MST= 29.50 days). In addition, CHAM-MTC showed protective ability against the oxidative stress and hepatic damage induced by EAC and MTC treatment. CONCLUSION: The combination of MTC with CHAM-NE could be valuable in enhancing the therapeutic efficacy of MTC against EAC and in eliminating MTC-induced hepatotoxicity.

The effect of air pockets in the urinary bladder on the temperature distribution during loco-regional hyperthermia treatment of bladder cancer patients.

PURPOSE: Loco-regional hyperthermia combined with mitomycin C is used for treatment of nonmuscle invasive bladder cancer (NMIBC). Air pockets may be present in the bladder during treatment. The aim of this study is to quantify the effect of air pockets on the thermal dose of the bladder. METHODS: We analysed 16 patients treated for NMIBC. Loco-regional hyperthermia was performed with the in-house developed 70 MHz AMC-4 hyperthermia device. We simulated treatments with the clinically applied device settings using Plan2Heat (developed in-house) including the air pockets delineated on CT scans made following treatment, and with the same volume filled with urine. Temperature distributions simulated with and without air pockets were compared. RESULTS: The average air and fluid volumes in the bladder were 6.0 ml (range 0.8 - 19.3 ml) and 183 ml (range 47-322 ml), respectively. The effect of these air pockets varied strongly between patients. Averaged over all patients, the median bladder wall temperature (T50) remained unchanged when an air pocket was present. Temperature changes exceeded ±0.2 °C in, on average, 23% of the bladder wall volume (range 1.3-59%), in 6.0% (range 0.6-20%) changes exceeded ±0.5 °C and in 3.2% (range 0.0-7.4%) changes exceeded ±1.0 °C. There was no correlation between the differences in temperature and the air pocket or bladder volume. There was a positive correlation between air pocket surface and temperature heterogeneity. CONCLUSION: Presence of air causes more heterogeneous bladder wall temperatures and lower T90, particularly for larger air pockets. The size of air pockets must therefore be minimized during bladder hyperthermia treatments.

Cytotoxicity and apoptosis enhancement in breast and cervical cancer cells upon coadministration of mitomycin C and essential oils in nanoemulsion formulations.

The present study aimed to solubilize the antineoplastic agent, mitomycin C (MMC), in two nanoemulsions (NEs) consisting of different essential oils (ginger (Gi) and frankincense (Fr)) in order to examine their anticancer activities on the HeLa cervical cancer cells and MCF-7 breast cancer cells. The two NEs-based Gi and Fr oil were produced by a high-pressure homogenization technique followed by solubilizing of the MMC in both NE formulas. The produced formulas were physically characterized by zetasizer and were applied on HeLa and MCF-7 cells at various concentrations for 24 h. The cytotoxicity assays were performed in vitro, using MTT assay, Coomassie blue staining for cellular morphology evaluation, and DAPI fluorescent staining for molecular cell death assessment. The average droplet diameters of the blank NEs have markedly increased and the charges of the droplets were significantly reversed when MMC was loaded. The potential cytotoxicity of the blank and combined formulas on HeLa and MCF-7 cells were dose-dependent and significantly greater than the toxicities of the free MMC. Among the MMC-loaded NE formulas, Fr-MMC has endured the nuclear apoptosis in HeLa cells at a lower concentration and reported the least % of florescence uptake compared to Gi-MMC. In contrast, the combination formula, Gi-MMC, has the strongest apoptotic effect on the MCF-7 cell line since it has the least % florescence uptake compared to the other formulations. Mixing MMC with Gi-NE and Fr-NE has considerably improved its cytotoxicity on the MCF-7 and HeLa cells.

Intravesical radiofrequency induced hyperthermia enhances mitomycin C accumulation in tumour tissue.

INTRODUCTION: Non-muscle invasive bladder cancer (NMIBC) is a highly recurrent disease with potential progression to muscle invasive disease despite the standard bladder instillations with mitomycin C (MMC) or Bacille Calmette-Guérin immunotherapy. Therefore, alternatives such as radiofrequency-induced chemohyperthermia (RF-CHT) with MMC are being investigated. The mechanism explaining the efficacy of RF-CHT is only partly understood. We examined whether RF-CHT results in higher MMC tissue concentrations as compared to cold MMC instillation. PATIENTS AND METHODS: Prior to a planned transurethral resection of bladder tumour (TURBT), patients with stage Ta NMIBC were allocated to either (1) cold MMC instillation or (2) RF-CHT. After MMC instillation, three biopsies were taken of both normal and tumour tissue. Biopsies were snap-frozen and MMC tissue concentrations were analysed using ultra-performance liquid chromatography. RESULTS: Eleven patients were included of which six received RF-CHT. Ten patients had TaG2-LG/HG papillary tumours at pathology. One patient in the RF-CHT group appeared to be free of malignancy and was excluded from the analysis as no tumour biopsies were available. The median MMC concentration in tumour tissue was higher in the RF-CHT group (median 665.00 ng/g vs. 63.75 ng/g, U = 51.0, p = 0.018). Moreover, in both techniques the MMC concentration was lower in normal tissue compared to tumour tissue. Tissue MMC concentration measurements varied substantially within, and between, different patients from the same group. CONCLUSION: Intravesical RF-CHT results in higher tumour MMC concentrations vs. cold MMC instillation which contributes to its superior efficacy.

Platinum agents and mitomycin C-specific complications in cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC).

INTRODUCTION: Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have been found to prolong survival in patients with peritoneal disease but is associated with significant morbidity. We evaluate the perioperative complications and the association with the chemotherapy agent used for HIPEC. METHODS: Retrospective analysis of a prospectively collected database of CRS-HIPEC cases between April 2001 and February 2016 was performed. Patients were stratified by the chemotherapy used, and perioperative complications were compared. RESULTS: Out of 214 CRS-HIPEC cases, 113 procedures used Mitomycin-C(MMC), 92 used cisplatin, 8 used oxaliplatin and the HIPEC regimen for one procedure was not recorded and excluded. 94 patients (44%) suffered low-grade complications (grade I-II), and 49 patients (23%) suffered high-grade complications (grade III-V). The frequency of low-grade complications for the cisplain, oxaliplatin and MMC groups were 49%, 50% and 40%, respectively, whereas that of high-grade complications were 24%, 50% and 20%, respectively. HIPEC with platinum agents was associated with a higher rate of acute renal impairment (ARI) compared to MMC (32% and 62% for cisplatin and oxaliplatin vs. 5.6% for MMC), whereas grade IV ARI requiring dialysis occurred only in the cisplatin group (5.6%). HIPEC with oxaliplatin was associated with higher rates of post-operative bleeding (25% vs. 1.1% and 0.88%). Rates of other complications did not differ significantly between the groups receiving different HIPEC regimens. CONCLUSIONS: The overall complication rates do not significantly differ after HIPEC with MMC and platinum based agents. Renal impairment tends to be more common and of greater severity when a platinum agent is used, whereas oxaliplatin is associated with significant post-operative bleeding.

Phyllanthus emblica Linn. fruit extract potentiates the anticancer efficacy of mitomycin C and cisplatin and reduces their genotoxicity to normal cells in vitro.

OBJECTIVE: Fruit of Phyllanthus emblica Linn. (PE) is widely consumed as a functional food and used as a folk medicine due to its remarkable nutritional and pharmacological effects. Mitomycin C (MMC) and cisplatin (cDDP) are the most widely used forms of chemotherapeutic drug, but their clinical use is limited by their genotoxicity to normal cells. We aimed to determine whether PE has potential to reduce the genotoxicity, while improving the anticancer effect, of MMC and cDDP. METHODS: Cell proliferation was evaluated using the trypan blue exclusion assay and colony-forming assay. Genomic instability (GIN) was measured using the cytokinesis-block micronucleus assay. RESULTS: Co-treatment (72 h) with PE at 20-320 µg/ml significantly enhanced the efficacy of MMC (0.05 µg/ml) and cDDP (1 µg/ml) against Colo205 colorectal cancer cells (P<0.05), and at 80-320 µg/ml significantly decreased MMC- and cDDP-induced GIN and multinucleation in normal colonic NCM460 cells (P<0.05). PE significantly decreased the mitotic index (P<0.01), blocked mitotic progression (P<0.05), and promoted apoptosis (P<0.01) in MMC- and cDDP-treated NCM460 cells, suggesting that PE-mediated inhibition of mitosis and induction of apoptosis may limit the division and survival of highly damaged cells. Also, PE was found to inhibit the clonal expansion of MMC- and cDDP-treated NCM460 cells (P<0.05) and decrease the heterogeneity of the surviving clones. CONCLUSIONS: PE potentiates the anticancer efficacy of MMC and cDDP, while preventing their genotoxicity and inhibiting clonal expansions of unstable genomes in normal cells. These data suggest that PE has the potential to reduce the risk of secondary cancers induced by chemotherapeutics.

Piperine (PP) enhanced mitomycin-C (MMC) therapy of human cervical cancer through suppressing Bcl-2 signaling pathway via inactivating STAT3/NF-κB.

Piperine (PP), an alkaloid from black and long peppers (Piper nigrum Linn &Piper longum Linn), exhibits antitumor activities in vitro and in vivo. We investigated the ability of piperine (PP) to reverse the drug resistance of human cervical cancer cells. In our study, the cervica cancer cells resistant to mitomycin-C (MMC) treatment were used. We found the growth inhibitory effects of piperine on human cervical cancer cell, which were resistant to MMC. Piperine and MMC co-treatment resulted in a dose-dependent suppression of the cell proliferation. Decreasing of phosphorylated-signal transducer and activator of transcription (p-STAT3) was linked to the suppression of p65 by PP and MMC combinational treatment. Additionally, the presence of PP potentiated the effects of MMC on apoptosis induction in cervical cancer cells with drug resistance, which was dependent on Bcl-2 inhibition. The pro-apoptotic proteins of Bax and Bid were up-regulated, accompanied with Caspase cleavage. Moreover, in mice xenograft models, the combined therapy inhibited tumor growth compared to the PP or MMC mono-therapy group. Our data indicated a novel therapeutic strategy of PP to potentiate MMC-induced anti-tumor effect on cervical cancer cells with drug resistance through blocking p-STAT3/p65 and Bcl-2 activation.

Tissue-engineered human 3D model of bladder cancer for invasion study and drug discovery.

The tumour microenvironment is critical to both the initiation and maintenance of tumorigenesis. Reconstitution of the microenvironment is a major challenge for in vitro cancer models. Indeed, conventional 2D culture systems cannot replicate the complexity, diversity and dynamic nature of the tumour microenvironment. In this study, we have developed a 3D endotheliazed vesical equivalent by using tissue engineering from primary human cells in which non-invasive or invasive bladder cancer (BCa) cell lines, cultured as compact spheroids, were incorporated. Invasive BCa cells cross the basement membrane and invade the stromal compartment whereas non-invasive BCa cells are confined to the urothelium. Our 3D BCa model could be used as a reliable model for assessing drug responses, potentially reducing or partially replacing animal experiments, and thus should have applications in the identification of novel targets as well as toxicological evaluation of anti-cancer therapies.

An Effective Counterselection System for Listeria monocytogenes and Its Use To Characterize the Monocin Genomic Region of Strain 10403S.

Construction of Listeria monocytogenes mutants by allelic exchange has been laborious and time-consuming due to lack of proficient selection markers for the final recombination event, that is, a marker conveying substance sensitivity to the bacteria bearing it, enabling the exclusion of merodiploids and selection for plasmid loss. In order to address this issue, we engineered a counterselection marker based on a mutated phenylalanyl-tRNA synthetase gene (pheS*). This mutation renders the phenylalanine-binding site of the enzyme more promiscuous and allows the binding of the toxic p-chloro-phenylalanine analog (p-Cl-phe) as a substrate. When pheS* is introduced into L. monocytogenes and highly expressed under control of a constitutively active promoter, the bacteria become sensitive to p-Cl-phe supplemented in the medium. This enabled us to utilize pheS* as a negative selection marker and generate a novel, efficient suicide vector for allelic exchange in L. monocytogenes We used this vector to investigate the monocin genomic region in L. monocytogenes strain 10403S by constructing deletion mutants of the region. We have found this region to be active and to cause bacterial lysis upon mitomycin C treatment. The future applications of such an effective counterselection system, which does not require any background genomic alterations, are vast, as it can be modularly used in various selection systems (e.g., genetic screens). We expect this counterselection marker to be a valuable genetic tool in research on L. monocytogenesIMPORTANCEL. monocytogenes is an opportunistic intracellular pathogen and a widely studied model organism. An efficient counterselection marker is a long-standing need in Listeria research for improving the ability to design and perform various genetic manipulations and screening systems for different purposes. We report the construction and utilization of an efficient suicide vector for allelic exchange which can be conjugated, leaves no marker in the bacterial chromosome, and does not require the use of sometimes leaky inducible promoters. This highly efficient genome editing tool for L. monocytogenes will allow for rapid sequential mutagenesis, introduction of point mutations, and design of screening systems. We anticipate that it will be extensively used by the research community and yield novel insights into the diverse fields studied using this model organism.

Mitomycin C-treated human-induced pluripotent stem cells as a safe delivery system of gold nanorods for targeted photothermal therapy of gastric cancer.

Human-induced pluripotent stem cells (iPS) possess an intrinsic tumor tropism ability. However, iPS cells are impeded in clinical applications of tumor therapy due to the formation of teratomas and their survival in normal organs such as the liver, lungs, spleen and kidneys. Mitomycin C (MMC) can overcome this limitation by suppressing iPS proliferation. Herein, we fabricated a safe delivery system of iPS cells treated with MMC loading with gold nanorods (AuNRs) for the targeted photothermal treatment of gastric cancer. Our results showed that the tumor cells were efficiently killed by the heat generated from the gold nanorods, and the iPS cells ultimately died due to the action of MMC seven days after the photothermal treatment. This suggested that pre-treated iPS cells with MMC can be used as a novel and safe approach for targeted tumor therapy. This paves the road for clinical translation in the future.

Repurposing the anticancer drug mitomycin C for the treatment of persistent Acinetobacter baumannii infections.

Acinetobacter baumannii is an emergent opportunistic bacterial pathogen responsible for recalcitrant infections owing to its high intrinsic tolerance to most antibiotics; therefore, suitable strategies to treat these infections are needed. One plausible approach is the repurposing of drugs that are already in use. Among them, anticancer drugs may be especially useful due their cytotoxic activities and ample similarities between bacterial infections and growing tumours. In this work, the effectiveness of four anticancer drugs on the growth of A. baumannii ATTC BAA-747 was evaluated, including the antimetabolite 5-fluorouracil and three DNA crosslinkers, namely cisplatin, mitomycin C (MMC) and merphalan. MMC was the most effective drug, having a minimum inhibitory concentration for 50% of growth in Luria-Bertani medium at ca. 7 µg/mL and completely inhibiting growth at 25 µg/mL. Hence, MMC was tested against a panel of 21 clinical isolates, including 18 multidrug-resistant (MDR) isolates, 3 of which were sensitive only to colistin. The minimum inhibitory concentrations and minimum bactericidal concentrations of MMC in all tested strains were found to be similar to those of A. baumannii ATCC BAA-747, and MMC also effectively killed stationary-phase, persister and biofilm cells. Moreover, MMC was able to increase survival of the insect larvae Galleria mellonella against an otherwise lethal A. baumannii infection from 0% to ≥53% for the antibiotic-sensitive A. baumannii ATCC BAA-747 strain and the MDR strains A560 and A578. Therefore, MMC is highly effective at killing the emergent opportunistic pathogen A. baumannii.