Antitumor activity of common antibiotics against superficial bladder cancer

Effect of Ciprofloxacin-Loaded Niosomes on Escherichia coli and Staphylococcus aureus Biofilm Formation

Infections caused by bacterial biofilms represent a global health problem, causing considerable patient morbidity and mortality in addition to an economic burden. Escherichia coli, Staphylococcus aureus, and other medically relevant bacterial strains colonize clinical surfaces and medical devices via biofilm in which bacterial cells are protected from the action of the immune system, disinfectants, and antibiotics. Several approaches have been investigated to inhibit and disperse bacterial biofilms, and the use of drug delivery could represent a fascinating strategy. Ciprofloxacin (CIP), which belongs to the class of fluoroquinolones, has been extensively used against various bacterial infections, and its loading in nanocarriers, such as niosomes, could support the CIP antibiofilm activity. Niosomes, composed of two surfactants (Tween 85 and Span 80) without the presence of cholesterol, are prepared and characterized considering the following features: hydrodynamic diameter, ζ-potential, morphology, vesicle bilayer characteristics, physical-chemical stability, and biological efficacy. The obtained results suggest that: (i) niosomes by surfactants in the absence of cholesterol are formed, can entrap CIP, and are stable over time and in artificial biological media; (ii) the CIP inclusion in nanocarriers increase its stability, with respect to free drug; (iii) niosomes preparations were able to induce a relevant inhibition of biofilm formation.

Influence of Antibiotic Administration on the Urinary Bladder Cancer Early Recurrence Rate

Bladder cancer tends to recur, making treatment one of the most expensive in oncology. The limited efficacy and high cost of adjuvant therapies in the treatment of bladder cancer prompt research on new drugs which could replace them. In vitro studies have established that antibiotics can have a cytostatic and cytotoxic effect on urinary bladder cancer cells. The objective of the study was to investigate the influence of antibiotics on the recurrence rate of bladder cancer. In a retrospective study, we analyzed a group of 199 patients with urinary bladder cancer from four urological centers. The study groups consisted of 40 patients who received ciprofloxacin and 83 patients who received beta-lactams as perioperative antimicrobial prophylaxis. The control group included 76 patients who did not get perioperative antimicrobial prophylaxis. The groups were analyzed for risk stratification, degree of malignancy, and size of the primary tumor. The average follow-up time was 24 months. The main focus of the study was to investigate the early recurrence rate of bladder cancer among studied groups, which could correlate with the effectiveness of currently used intravesical instillations. Additionally, cancer’s early progression was examined. Regardless of the division used, the highest recurrence rate was found in the ciprofloxacin group. There were no statistical differences in the recurrence rate between patients who received beta-lactams and patients who did not receive any antibiotics. In addition, there were no differences due to the progression rate between the groups. Perioperative antibiotic administration does not influence the early recurrence rate in patients with nonmuscle invasive urothelial bladder cancer.

Quinolones as a Potential Drug in Genitourinary Cancer Treatment-A Literature Review

Quinolones, broad-spectrum antibiotics, are frequently prescribed by urologists for many urological disorders. The mechanism of their bactericidal activity is based on the inhibition of topoisomerase II or IV complex with DNA, which consequently leads to cell death. It has been observed that these antibiotics also act against the analogous enzymes present in eukaryotic cells. Due to their higher accumulation in urine and prostate tissue than in serum, these drugs seem to be ideal candidates for application in genitourinary cancer treatment. In this study, an extensive literature review has been performed to collect information about concentrations achievable in urine and prostate tissue together with information about anticancer properties of 15 quinolones. Special attention was paid to the application of cytotoxic properties of quinolones for bladder and prostate cancer cell lines. Data available in the literature showed promising properties of quinolones, especially in the case of urinary bladder cancer treatment. In the case of prostate cancer, due to low concentrations of quinolones achievable in prostate tissue, combination therapy with other chemotherapeutics or another method of drug administration is necessary.

Effects of Metformin Combined With Antifolates on HepG2 Cell Metabolism and Cellular Proliferation

Hepatocellular carcinoma (HCC), one of the most prevalent types of cancers worldwide, continues to maintain high levels of resistance to standard therapy. As clinical data revealed poor response rates, the need for developing new methods has increased to improve the overall wellbeing of patients with HCC. Furthermore, a growing body of evidence shows that cancer metabolic changes are a key feature of many types of human malignancies. Metabolic reprogramming refers to cancer cells’ ability to change their metabolism in order to meet the increased energy demand caused by continuous growth, rapid proliferation, and other neoplastic cell characteristics. For these reasons, metabolic pathways may become new therapeutic and chemopreventive targets. The aim of this study was to investigate the metabolic alterations associated with metformin (MET), an anti-diabetic agent when combined with two antifolate drugs: trimethoprim (TMP) or methotrexate (MTX), and how metabolic changes within the cancer cell may be used to increase cellular death. In this study, single drugs and combinations were investigated using in vitro assays including cytotoxicity assay (MTT), RT-qPCR, annexin V/PI apoptosis assay, scratch wound assay and Seahorse XF analysis, on a human HCC cell line, HepG2. The cytotoxicity assay showed that the IC₅₀ of MET as single therapy was 44.08 mM that was reduced to 22.73 mM and 29.29 mM when combined with TMP and MTX, respectively. The co-treatment of both drugs increased p53 and Bax apoptotic markers, while decreased the anti-apoptotic marker; Bcl-2. Both combinations increased the percentage of apoptotic cells and halted cancer cell migration when compared to MET alone. Furthermore, both combinations decreased the MET-induced increase in glycolysis, while also inducing mitochondrial damage, altering cancer cell bioenergetics. These findings provide an exciting insight into the anti-proliferative and apoptotic effects of MET and anti-folates on HepG2 cells, and how in combination, may potentially combat the aggressiveness of HCC.

Microbial Metabolites of Flavanols in Urine are Associated with Enhanced Anti-Proliferative Activity in Bladder Cancer Cells In Vitro

Flavanols are metabolized by the gut microbiota to bioavailable metabolites, and the absorbed fraction is excreted primarily via urine. Uroepithelial cells are thus a potential site of activity due to exposure to high concentrations of these compounds. Chemoprevention by flavanols may be partly due to these metabolites. In Vitro work in this area relies on a limited pool of commercially available microbial metabolites, and little has been done in bladder cancer. The impact of physiologically relevant mixtures of flavanols and their metabolites remains unknown. Rats were fed various flavanols and urine samples, approximating the bioavailable metabolome, were collected. Urines were profiled by UPLC-MS/MS, and their anti-proliferative activities were assayed In Vitro in four bladder cancer models. Significant interindividual variability was observed for composition and proliferation. Microbial metabolite concentrations (valerolactones, phenylalkyl acids and hippuric acids) were positively associated with reduced bladder cancer proliferation In Vitro, while native flavanols were poorly correlated with activity. These results suggest that microbial metabolites may be responsible for chemoprevention in uroepithelial cells following flavanol consumption. This highlights the potential to use individual genetics and microbial metabotyping to design personalized dietary interventions for cancer prevention and/or adjuvant therapy to reduce bladder cancer incidence and improve outcomes.

Antibacterial Therapy by Ag+ Ions Complexed with Titan Yellow/Congo Red and Albumin during Anticancer Therapy of Urinary Bladder Cancer

According to the World Health Organization report, the increasing antibiotic resistance of microorganisms is one of the biggest global health problems. The percentage of bacterial strains showing multidrug resistance (MDR) to commonly used antibiotics is growing rapidly. Therefore, the search for alternative solutions to antibiotic therapy has become critical to combat this phenomenon. It is especially important as frequent and recurring infections can cause cancer. One example of this phenomenon is urinary tract infections that can contribute to the development of human urinary bladder carcinoma. This tumor is one of the most common malignant neoplasms in humans. It occurs almost three times more often in men than in women, and in terms of the number of cases, it is the fifth malignant neoplasm after prostate, lung, colon, and stomach cancer. The risk of developing the disease increases with age. Despite the improvement of its treatment methods, the current outcome in the advanced stages of this tumor is not satisfactory. Hence, there is an urgent need to introduce innovative solutions that will prove effective even in the advanced stage of the disease. In our study, a nanosystem based on ionic silver (Ag⁺) bound to a carrier—Titan yellow (TY) was analyzed. The possibility of binding the thus formed TY-Ag system to Congo red (CR) and albumin (BSA) was determined. TY-Ag binding to CR provides for better nanosystem solubility and enables its targeted intracellular transport and binding to immune complexes. The binding of TY-Ag or CR-TY-Ag to albumin also protects the system against the uncontrolled release of silver ions. It will also allow the delivery of silver in a targeted manner directly to the desired site in the case of intravenous administration of such a system. In this study, the MIC (Minimum Inhibitory Concentration) and MBC (Minimum Bactericidal Concentration) values of the TY-Ag or BSA-TY-Ag systems were determined in two reference strains (Escherichia coli and Staphylococcus aureus). The paper presents nanosystems with a size of about 40–50 nm, with an intense antibacterial effect obtained at concentrations of 0.019 mM. We have also discovered that TY-Ag free or complexed with BSA (with a minimal Ag⁺ dose of 15–20 μM) inhibited cancer cells proliferation. TY-Ag complex diminished migration and effectively inhibited the T24 cell viability and induced apoptosis. On the basis of the obtained results, it has been shown that the presented systems may have anti-inflammatory and antitumor properties at the same time. TY-Ag or BSA-TY-Ag are new potential drugs and may become in future important therapeutic compounds in human urinary bladder carcinoma treatment and/or potent antimicrobial factors as an alternative to antibiotics.

Ciprofloxacin and Levofloxacin as Potential Drugs in Genitourinary Cancer Treatment-The Effect of Dose-Response on 2D and 3D Cell Cultures

Introduction: Introducing new drugs for clinical application is a very difficult, long, drawn-out, and costly process, which is why drug repositioning is increasingly gaining in importance. The aim of this study was to analyze the cytotoxic properties of ciprofloxacin and levofloxacin on bladder and prostate cell lines in vitro. Methods: Bladder and prostate cancer cell lines together with their non-malignant counterparts were used in this study. In order to evaluate the cytotoxic effect of both drugs on tested cell lines, MTT assay, real-time cell growth analysis, apoptosis detection, cell cycle changes, molecular analysis, and 3D cultures were examined. Results: Both fluoroquinolones exhibited a toxic effect on all of the tested cell lines. In the case of non-malignant cell lines, the cytotoxic effect was weaker, which was especially pronounced in the bladder cell line. A comparison of both fluoroquinolones showed the advantage of ciprofloxacin (lower doses of drug caused a stronger cytotoxic effect). Both fluoroquinolones led to an increase in late apoptotic cells and an inhibition of cell cycle mainly in the S phase. Molecular analysis showed changes in BAX, BCL2, TP53, and CDKN1 expression in tested cell lines following incubation with ciprofloxacin and levofloxacin. The downregulation of topoisomerase II genes (TOP2A and TOP2B) was noticed. Three-dimensional (3D) cell culture analysis confirmed the higher cytotoxic effect of tested fluoroquinolone against cancer cell lines. Conclusions: Our results suggest that both ciprofloxacin and levofloxacin may have great potential, especially in the supportive therapy of bladder cancer treatment. Taking into account the low costs of such therapy, fluoroquinolones seem to be ideal candidates for repositioning into bladder cancer therapeutics.

Effects of infections on the pathogenesis of cancer

Several studies have shown an inverse relationship between acute infections and cancer development. On the other hand, there is a growing evidence that chronic infections may contribute significantly to the carcinogenesis. Factors responsible for increased susceptibility to infections may include modifications of normal defence mechanisms or impairment of host immunity due to altered immune function, genetic polymorphisms, ageing and malnourishment. Studies have demonstrated that children exposed to febrile infectious diseases show a subsequent reduced risk for ovarian cancer, melanoma and many other cancers, while common acute infections in adults are associated with reduced risks for melanoma, glioma, meningioma and multiple cancers. Chronic inflammation associated with certain infectious diseases has been suggested as a cause for the development of tumours. Mechanisms of carcinogenesis due to infections include cell proliferation and DNA replication by mitogen-activated protein kinase pathway, production of toxins that affect the cell cycle and lead to abnormal cell growth and inhibition of apoptosis. This review was aimed to summarize the available evidence on acute infections as a means of cancer prevention and on the role of chronic infections in the development and progression of cancer.

Highly sensitive electrode materials for the voltammetric determination of nitrofurantoin based on zinc cobaltate nanosheets

Schematic illustration of the electrocatalytic activity of nitrofurantoin (NFT) on ZnCo₂O₄ nanosheets.

Facile synthesis of ultrathin NiSnO3 nanoparticles for enhanced electrochemical detection of an antibiotic drug in water bodies and biological samples

The highly sensitive real-time detection of antibiotic drugs (nitrofurantoin; NFT) has drawn significant research attention due to the extensive use of antibiotics, which may cause serious threats to environment as well as living things.

Hierarchical construction and characterization of lanthanum molybdate nanospheres as an unassailable electrode material for electrocatalytic sensing of the antibiotic drug nitrofurantoin

In this work, lanthanum molybdate nanospheres (LMNSs) were prepared by employing a co-precipitation methodology, and their electrochemical activity against nitrofurantoin (NF) was reported.

Repositioning of fluoroquinolones from antibiotic to anti-cancer agents: An underestimated truth

Increasing development costs and higher failure rate in clinical trials has reduced the repertoire of newer drugs in the market for clinical use. The most appropriate approach to end the search for newer drugs is "Repositioning", as it requires less time and money to explore new indication of existing drug or failed drug. In the past, several drugs have been repositioned for different indication but the full potential remains unharnessed. With rise in cancer prevalence and treatment costs, it is imperative to search for newer drugs and the use of repositioning approach may help us. Fluoroquinolones has been used as antibiotics for over four decades now, but recent research highlighted their use as pharmacological compounds with multifaceted implication. Repositioning of fluoroquinolones into anti-cancer molecule seems to be a highly plausible option owing to their profound immunomodulatory, pro-apoptotic, anti-proliferative and anti-metastatic potential. The present review provides a comprehensive account of the recent and past explorations pertaining to the anti-cancer activity of fluoroquinolones and also discusses the various approaches that are being considered to remodel them for the treatment of cancer.

Ciprofloxacin impairs mitochondrial DNA replication initiation through inhibition of Topoisomerase 2

Maintenance of topological homeostasis is vital for gene expression and genome replication in all organisms. Similar to other circular genomes, also mitochondrial DNA (mtDNA) is known to exist in various different topological forms, although their functional significance remains unknown. We report here that both known type II topoisomerases Top2α and Top2β are present in mammalian mitochondria, with especially Top2β regulating the supercoiling state of mtDNA. Loss of Top2β or its inhibition by ciprofloxacin results in accumulation of positively supercoiled mtDNA, followed by cessation of mitochondrial transcription and replication initiation, causing depletion of mtDNA copy number. These mitochondrial effects block both cell proliferation and differentiation, possibly explaining some of the side effects associated with fluoroquinolone antibiotics. Our results show for the first time the importance of topology for maintenance of mtDNA homeostasis and provide novel insight into the mitochondrial effects of fluoroquinolones.

Quinone and nitrofurantoin redox cycling by recombinant cytochrome b5 reductase

NADH cytochrome b₅ reductase mediates electron transfer from NADH to cytochrome b₅ utilizing flavin adenine dinucleotide as a redox cofactor. Reduced cytochrome b₅ is an important cofactor in many metabolic reactions including cytochrome P450-mediated xenobiotic metabolism, steroid biosynthesis and fatty acid metabolism, hemoglobin reduction, and methionine and plasmalogen synthesis. Using recombinant human enzyme, we discovered that cytochrome b5 reductase mediates redox cycling of a variety of quinones generating superoxide anion, hydrogen peroxide, and, in the presence of transition metals, hydroxyl radicals. Redox cycling activity was oxygen-dependent and preferentially utilized NADH as a co-substrate; NADH was 5-10 times more active than NADPH in supporting redox cycling. Redox cycling activity was greatest for 9,10-phenanthrenequinone and 1,2-naphthoquinone, followed by 1,4-naphthoquinone and 2-methyl-1,4-naphthoquinone (menadione), nitrofurantoin and 2-hydroxyestradiol. Using menadione as the substrate, quinone redox cycling was found to inhibit reduction of cytochrome b₅ by cytochrome b₅ reductase, as measured by heme spectral changes in cytochrome b₅. Under anaerobic conditions where redox cycling is inhibited, menadione had no effect on the reduction of cytochrome b₅. Chemical redox cycling by cytochrome b₅ reductase may be important in generating cytotoxic reactive oxygen species in target tissues. This activity, together with the inhibition of cytochrome b₅ reduction by redox-active chemicals and consequent deficiencies in available cellular cytochrome b₅, are likely to contribute to tissue injury following exposure to quinones and related redox active chemicals.

Capsaicin enhances anti-proliferation efficacy of pirarubicin via activating TRPV1 and inhibiting PCNA nuclear translocation in 5637 cells

The recurrence of bladder cancer after surgery with or without chemotherapy remains a major challenge in bladder cancer treatment. Previous studies have shown that transient receptor potential vanilloid 1 (TRPV1) acts as a tumor suppressor through inducing apoptosis in bladder cancer cells. However, whether activation of TRPV1 has any synergistic effects with pirarubicin (THP), one of main drugs used in urinary bladder instillation chemotherapy to improve chemotherapeutic efficacy has remained elusive. The present study verified that TRPV1 was differentially expressed in bladder cancer cell lines. Furthermore, activation of TRPV1 by capsaicin was shown to induce growth inhibition of 5637 cells in which TRPV1 was highly expressed, while the growth of T24 cells, which express TRPV1 at low levels, was not affected. In addition, the present study demonstrated that activation of TRPV1 enhanced the anti‑proliferative effects of pirarubicin using an MTT assay and cell cycle analysis. Finally, immunofluorescent microscopy revealed that activation of TRPV1 prevented the translocation of proliferating cell nuclear antigen to the nucleus. This phenomenon was reversed by pre‑treatment with capsazepine, a specific TRPV1 antagonist. In conclusion, the present study confirmed the anti‑tumor activity of TRPV1 against bladder cancer. Activation of TRPV1 may be applied as a novel strategy to treat bladder cancer or enhance the therapeutic efficacy of traditional chemotherapeutic drugs.

Synthesis of novel ethyl 1-ethyl-6-fluoro-7-(fatty amido)-1,4-dihydro-4-oxoquinoline-3-carboxylate derivatives and their biological evaluation

A series of novel ethyl 1-ethyl-6-fluoro-7-(fatty amido)-1,4-dihydro-4-oxoquinoline-3-carboxylate derivatives were prepared through multistep synthesis. The key step in the synthesis was to obtain the C-7 fatty amide derivative. The azide was selectively formed at C-7 position using sodium azide at 60°C. Subsequently, the azide was reduced under mild conditions using zinc and ammonium chloride to form the corresponding amine. The synthesized derivatives were further subjected to biological evaluation studies like cytotoxicity against a panel of cancer cell lines such as DU145, A549, SKOV3, MCF7 and normal lung cells, IMR-90 as well as with antimicrobial and antioxidant activities. It was observed that the carboxylated quinolone derivatives with hexanoic (8a), octanoic (8b), lauric (8d) and myristic (8e) moieties exhibited promising cytotoxicity against all the tested cancer cell lines. The results also suggested that hexanoic acid-based fatty amide carboxylated quinolone derivative (8a) exhibited promising activity against both bacterial and fungal strains and significant antibacterial activity was observed against Staphylococcus aureus MTCC 96 (MIC value of 3.9μg/mL). The compound 8a also showed excellent anti-biofilm activity against Staphylococcus aureus MTCC 96 and Bacillus subtilis MTCC 121 with MIC values of 2.1 and 4.6μg/mL, respectively.

Recurrent urinary tract infection and risk of bladder cancer in the Nijmegen bladder cancer study

BACKGROUND

Controversy exists on whether urinary tract infection (UTI) is a risk factor for urinary bladder cancer (UBC). Here, the association is investigated using data from one of the largest bladder cancer case-control studies worldwide.

METHODS

Information on (i) history and age at onset of regular cystitis ('regular low-UTI') and (ii) number and age at onset of UTI treated with antibiotics ('UTI-ab') from 1809 UBC patients and 4370 controls was analysed. Odds ratios (ORs) and 95% confidence intervals (CI) adjusted for age, education, smoking, and use of aspirin/ibuprofen were generated, for men and women separately.

RESULTS

Regular low-UTI was associated with an increased UBC risk (men: OR (95% CI) 6.6 (4.2-11); women: 2.7 (2.0-3.5)), with stronger effects in muscle-invasive UBC. Statistically significant decreased risks (ORs ∼0.65) were observed for up to five UTI-ab, specifically in those who (had) smoked and experienced UTI-ab at a younger age. In women, UTI experienced after menopause was associated with a higher UBC risk, irrespective of the number of episodes.

CONCLUSIONS

Regular cystitis is positively associated with UBC risk. In contrast, a limited number of episodes of UTI treated with antibiotics is associated with decreased UBC risk, but not in never-smokers and postmenopausal women.

In vitro effect of molluscan hemocyanins on CAL-29 and T-24 bladder cancer cell lines

The aim of this study was to investigate the anti-tumor effects of molluscan hemocyanins (Hcs) isolated from the marine snail Rapana venosa (RvH) and the garden snail Helix lucorum (HlH) on human bladder cancer cell lines. The antitumor effect of the native molecules of the above-mentioned Hcs and their subunits were examined in comparison to keyhole limpet hemocyanin (KLH), which is the most thoroughly studied Hc. The experiments were conducted using 2 human bladder cancer cell lines: CAL-29 and T-24. Doxorubicin hydrochloride (DOX) and mitomycin-C (MIT-C), which are routinely used in clinical practice to treat bladder cancer, were used for comparison. The viability of the 2 bladder cancer cell lines, used at a concentration of 20,000 cells/well, was measured by WST-1 assay at 24, 48 and 72 h after treatment with the above-mentioned Hcs and their isoforms at a concentration ranging from 0.8 to 500 μg/ml. A direct growth inhibitory effect on the tumor cells was observed mainly after treatment with the native molecule of HlH and the structural subunit, RvH1, at a concentration of 500 μg/ml. The native molecule of RvH exhibited an efficacy similar to that of KLH. However, the observed growth inhibitory effect of HlH was superior to that observed for KLH and RvH, when used at the same concentration. These findings demonstrate the antitumor effect of other Hcs, apart from KLH. Our data suggest that the native molecule of HlH and the subunit, RvH1, are alternative candidates for the treatment of human superficial bladder cancer.

Using antimicrobial adjuvant therapy in cancer treatment: a review

Recent clinical and pre-clinical data demonstrate that adjuvant antimicrobial therapy is beneficial in cancer treatment. There could be several reasons for this effect, which include treating cancer associated bacteria and viruses, prophylaxis of post-chemotherapy infections due to immunosuppression, and antiproliferative effect of certain antimicrobials. Targeting cancer associated viruses and bacteria with antimicrobial agents is currently used for gastric, cervical, hematopoietic, liver and brain cancer. However this treatment is effective only in combination with conventional therapies. Antimicrobials can also have a direct antiproliferative and cytotoxic effect, and can cause apoptosis. Moreover, some antimicrobials are known to be helpful in overcoming side effects of drugs commonly used in cancer treatment. Chemotherapy related bacteremia and neutropenia can be overcome by the appropriately timed use of antimicrobials. This review summarizes the data on the effects of antivirals and antibiotics on cancer treatment and describes their mechanisms.

Novel lipophilic 7H-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylic acid derivatives as potential antitumor agents: improved synthesis and in vitro evaluation

A convenient route for the synthesis of some acyloxymethyl esters and carboxamides of levofloxacin (LV) with modulated lipophilicity is described. The synthesized compounds were evaluated in vitro for their growth inhibitory effect in five human cancer cell lines. The most efficient LV derivatives (ester 2e and amide 4d) displayed IC(50) values in the 0.2-2.2 μM range, while IC(50) values for parent LV ranged between 70 and 622 μM depending on the cell line. The esters displayed no in vivo toxicity up to 80 mg/kg when administered intraperitoneally. This study thus shows that LV analogs displayed antitumor efficacy, at least in vitro, a feature that appeared to be independent from the lipophilicity of the grafted substituent.

Does ciprofloxacin have an obverse and a reverse?

Ciprofloxacin is an antibiotic that belongs to fluoroquinoles, characterized by broad spectrum of action against pathogens, especially Gram(-) aerobic bacilli. For a long time, it has been thought that ciprofloxacin has an effect only on bacterial cells. Now it is known, that this drug can significantly affect eukaryotic cells including human cancer cells. Its bactericidal action relay on inhibition of topoisomerase II, enzyme responsible for alterations in 3D structure of DNA during replication, transcription and chromatin condensation. Thanks to that, ciprofloxacin can induce cell cycle arrest and apoptosis of cancer cells. The effectiveness of ciprofloxacin was confirmed in several in vitro studies on tumor cell lines such as: human bladder cells, leukaemic cell lines, human osteosarcoma cells, human prostate cancer cells, human colorectal carcinoma cells and human non-small cell lung cancer cell line. Ciprofloxacin is particularly effective against non-small cell lung cancer mainly due to accumulation of ciprofloxacin in lung tissue after intravenous administration and its toxicity against lung cancer lines in vitro in a concentration and time-dependent manner.

Ciprofloxacin decreases survival in HT-29 cells via the induction of TGF-beta1 secretion and enhances the anti-proliferative effect of 5-fluorouracil

BACKGROUND AND PURPOSE

Fluoroquinolones are potent anti-microbial agents with multiple effects on host cells and tissues. Previous studies have highlighted their pro-apoptotic effect on human cancer cells and an immunoregulatory role in animal models of inflammatory bowel disease. We examined the effect of ciprofloxacin on proliferation, cell cycle and apoptosis of HT-29 cells, a human colonic epithelial cell line sensitive to transforming growth factor (TGF)-beta1-mediated growth inhibition and its role in TGF-beta1 production. We also examined the effect of ciprofloxacin on proliferation of HT-29 cells in combination with 5-fluorouracil (5-FU), a well-established pro-apoptotic agent.

EXPERIMENTAL APPROACH

Using subconfluent cultures of HT-29 and Caco-2 cells, we studied the effect of ciprofloxacin, TGF-beta1 and 5-FU on proliferation, apoptosis, necrosis and cell cycle. The effect of ciprofloxacin on TGF-beta1 mRNA expression and production was studied in RNA extracts and cell culture supernatants respectively, using confluent cultures.

KEY RESULTS

Ciprofloxacin decreased proliferation of HT-29 cells in a concentration- and time-dependent manner. This was mediated by accumulation of HT-29 cells into the S-phase but without any effect on apoptosis or necrosis. Additionally, ciprofloxacin enhanced the antiproliferative effect of 5-FU. Interestingly, ciprofloxacin was found to up-regulate TGF-beta1 production by HT-29 cells and its anti-proliferative effect was abolished when TGF-beta1 was blocked. Confirming this mechanism further, ciprofloxacin had no effect on Caco-2, a human colonic epithelial cell line that lacks functional TGF-beta1 receptors.

CONCLUSIONS AND IMPLICATIONS

We demonstrate a novel anti-proliferative and immunoregulatory effect of ciprofloxacin on human intestinal epithelial cells mediated via TGF-beta1.

Short-term administration of prulifloxacin in patients with nonmuscle-invasive bladder cancer: an effective option for the prevention of bacillus Calmette-Guérin-induced toxicity?

OBJECTIVE

To determine whether the new fluoroquinolone prulifloxacin might improve tolerance to Bacillus Calmette-Guérin (BCG) intravesical therapy in patients with bladder cancer.

PATIENTS AND METHODS

A series of 72 patients with intermediate- or high-risk nonmuscle-invasive bladder cancer were enrolled in this prospective, randomized, open-label, controlled clinical trial performed at a single tertiary care institution. After complete transurethral resection, patients were randomized to receive induction treatment with BCG and three capsules of prulifloxacin 600 mg or no prophylactic treatment (control group). Adverse events (AEs) were self-recorded by the patients after each instillation and classified by the investigator according to a classification grid considering account duration and intensity. Cystoscopy findings at 3 and 6 months were also recorded.

RESULTS

There was no significant difference in baseline symptoms between the groups. Overall, there was a significant decrease in the percentage of patients with at least one AE between instillations in prulifloxacin-treated group. The proportion of patients with moderate to severe AEs after the fourth instillation was significantly less in the prulifloxacin-treated group. There was a significant effect of prulifloxacin on the need for anti-tuberculosis treatment. More patients in the control group stopped or delayed the full induction course of BCG instillations (34% vs 19%, P=0.04). Recurrence rates were not affected by prulifloxacin treatment.

CONCLUSION

Prulifloxacin reduces the incidence of moderate to severe AEs from BCG intravesical therapy in patients with nonmuscle-invasive bladder cancer, improving compliance to the induction BCG course. These preliminary findings warrant further clinical research.

Urinary tract infections and reduced risk of bladder cancer in Los Angeles

We investigated the association between urinary tract infections (UTIs) and transitional cell carcinoma of the bladder in a population-based case–control study in Los Angeles covering 1586 cases and age-, gender-, and race-matched neighbourhood controls. A history of bladder infection was associated with a reduced risk of bladder cancer among women (odds ratio (OR), 0.66; 95% confidence interval (CI), 0.46–0.96). No effect was found in men, perhaps due to power limitations. A greater reduction in bladder cancer risk was observed among women with multiple infections (OR, 0.37; 95% CI, 0.18–0.78). Exclusion of subjects with a history of diabetes, kidney or bladder stones did not change the inverse association. A history of kidney infections was not associated with bladder cancer risk, but there was a weak association between a history of other UTIs and slightly increased risk among men. Our results suggest that a history of bladder infection is associated with a reduced risk of bladder cancer among women. Cytotoxicity from antibiotics commonly used to treat bladder infections is proposed as one possible explanation.

Antibiotic use predicts an increased risk of cancer

Antibiotic use has been hypothesized to be associated with the risk of cancer but the evidence is sparse and inconsistent. The aim of the present study was to determine whether antibiotic use predicts the development of various cancers. This nationwide cohort study included 3,112,624 individuals, aged 30-79 years, with no history of cancer. Information on their antibiotic use between 1995 and 1997 was obtained from the Drug Prescription Registry. During the period 1998-2004, 134,070 cancer cases were ascertained from the Finnish Cancer Registry. Cox proportional hazards regression was used to estimate the relative risks (RRs) with 95% confidence intervals (95% CIs). Antibiotic use was associated with an increased risk of cancer: for categories of increasing antibiotic use (0-1, 2-5 and >/=6 prescriptions), RRs (95% CIs) for cancer were 1.0 (reference), 1.27 (1.26-1.29) and 1.37 (1.34-1.40). RRs (for comparison of lowest and highest exposure group) for the most common primary sites i.e. prostate, breast, lung and colon were 1.39 (1.31-1.48), 1.14 (1.09-1.20), 1.79 (1.67-1.92), and 1.15 (1.04-1.26), respectively. RRs for other primary sites varied between 0.90 (0.76-1.05) for ovary to 2.60 (1.60-4.20) for endocrine gland (excluding thyroid). In conclusion, antibiotic use predicts an increased risk of cancer. Because of the design of our study the possibility of residual confounding cannot be excluded and further studies are required to confirm the results.

Role of cytochrome P450 reductase in nitrofurantoin-induced redox cycling and cytotoxicity

The one-electron reduction of redox-active chemotherapeutic agents generates highly toxic radical anions and reactive oxygen intermediates (ROI). A major enzyme catalyzing this process is cytochrome P450 reductase. Because many tumor cells highly express this enzyme, redox cycling of chemotherapeutic agents in these cells may confer selective antitumor activity. Nitrofurantoin is a commonly used redox-active antibiotic that possesses antitumor activity. In the present studies we determined whether nitrofurantoin redox cycling is correlated with cytochrome P450 reductase activity and cytotoxicity in a variety of cell lines. Recombinant cytochrome P450 reductase was found to support redox cycling of nitrofurantoin and to generate superoxide anion, hydrogen peroxide, and, in the presence of redox-active iron, hydroxyl radicals. This activity was NADPH dependent and inhibitable by diphenyleneiodonium, indicating a requirement for the flavin cofactors in the reductase. Nitrofurantoin-induced redox cycling was next analyzed in different cell lines varying in cytochrome P450 reductase activity including Chinese hamster ovary cells (CHO-OR) constructed to overexpress the enzyme. Nitrofurantoin-induced hydrogen peroxide production was 16-fold greater in lysates from CHO-OR cells than from control CHO cells. A strong correlation between cytochrome P450 reductase activity and nitrofurantoin-induced redox cycling among the cell lines was found. Unexpectedly, no correlation between nitrofurantoin-induced ROI production and cytotoxicity was observed. These data indicate that nitrofurantoin-induced redox cycling and subsequent generation of ROI are not sufficient to mediate cytotoxicity and that cytochrome P450 reductase is not a determinant of sensitivity to redox-active chemotherapeutic agents.

The anti-cancer effects of quinolone antibiotics?

A previous meta-analysis showed that quinolones administered for prophylaxis of infections among cancer patients reduced all-cause mortality. We extracted from the primary trials infection-related and all-cause mortality as reported and assessed the effect of quinolones on non-infection-related mortality through meta-analysis. Among trials comparing quinolones to placebo or no treatment, a significant reduction in non-infection-related mortality was observed (relative risk 0.54, 95% confidence interval 0.32-0.93, 15 trials, 3,320 patients). This finding might represent biased attribution of deaths to infection or might be compatible with an anti-cancer effect of quinolone antibiotics. We present further analyses addressing these possibilities.

Application of multiple parallel perfused microbioreactors and three-dimensional stem cell culture for toxicity testing

In this study, a multiple parallel perfused microbioreactor platform, TissueFlex, was developed which can be used to perform cell and tissue culture under almost uniform and precisely controlled environment in a mid-throughput and parallel manner. These microbioreactors were used to culture human bone marrow cells (hBMCs) in three-dimensional (3D) scaffolds and also in two-dimensional (2D) monolayer for comparison for upto 7 days. Several scaffolding materials were evaluated for this purpose in terms of easiness in handling, ability to support the hBMC growth, and feasibility for non-destructive optical assays. The feasibility and efficacy of using the developed 3D-hBMCs-based model tissue-constructs cultured in TissueFlex microbioreactors for drug evaluation and toxicity testing was then studied. As a demonstration case study, the cultured cells were challenged with two chemicals, trimethoprim and pyrimethamine, both known to be harmful to cellular activities, with different protocols. Cytotoxicity in terms of cell viability and growth was determined using the AlamarBlue assay. The 3D spatial variations in cell morphology and cell survival were also monitored using 3D optical imaging using non-linear multiphoton microscopy. The results show that (i) the data obtained from 3D hBMCs culture and from (2D) monolayer cultures on the effect of the tested chemicals on cell growth are significantly different, and that (ii) the perfused microbioreactor technology could provide a highly controlled and prolonged cell culture environment for testing of various drugs and chemicals. The outcome of this study demonstrated the feasibility and potentials of the using 3D stem cell based model tissues in TissueFlex microbioreactors for drug evaluation and toxicity testing of chemicals as an efficient and standardized alternative testing method.

Chemoprevention for Bladder Cancer

PURPOSE

Bladder cancer is the most expensive cancer to treat and follow in the United States due to often extended courses of treatment coupled with the necessity for frequent surveillance examinations. Because direct exposure to carcinogens is implicated in bladder cancer development and many potentially protective compounds are concentrated in urine, bladder cancer is a logical target for chemoprevention.

MATERIALS AND METHODS

We performed a MEDLINE search of the English language literature to identify reports of chemoprevention of bladder cancer. Study outcomes were evaluated and mechanisms of action were identified when possible. In cases of multiple reports of the same compound critical comparisons were performed.

RESULTS

For most putative chemopreventive agents against bladder cancer the results of different studies are conflicting. Megadose vitamins, certain vitamin A analogues and pyridoxines have been associated with promising findings. For vitamins C and E and selenium, studies showing benefit are balanced by studies showing no benefit. Other compounds, such as soy, green tea and isothiocyanates, have been suggested by some studies to be protective and by others to be tumor promoting.

CONCLUSIONS

For most bladder cancer chemopreventive agents studied to date results regarding efficacy vary, precluding the possibility of universal support by health care providers for this specific role. Megadose multivitamin supplements have demonstrated the ability to prevent bladder cancer recurrences in a single smaller study. Some analogues of vitamins A, B6, C and E have been shown to be beneficial in other disease processes, suggesting that these compounds may be advocated with the caveat that they do not have a specific protective role in bladder cancer. Data from randomized, prospective trials show a benefit in bladder cancer only after eliminating early or initial recurrences, suggesting the need for long-term administration of a chosen agent. Additional prospective trials with long-term followup, likely involving multiple institutions, are required before definitive recommendations can be made about chemoprevention for bladder cancer. In 2006 no oral agent can be recommended and to our knowledge the best chemopreventive strategy remains to be determined.