Affect DNA Synthesis Research Articles

Gemcitabine: Association with Thrombocytosis

Gemcitabine is a pyrimidine antimetabolite that affects DNA synthesis in the S-phase of the cell cycle. It is effective against cancers such as ovarian carcinoma, non-small cell lung cancer, and pancreatic cancer. However it causes significant side effects like myelosuppression, which leads to thrombocytopenia in about 71% of patients, prompting discontinuation of therapy. Even though thrombocytopenia is common, some patients experience thrombocytosis during Gemcitabine therapy, especially in the second and third cycles, possibly due to a rebound effect. Thrombocytosis is usually asymptomatic and occasionally leads to venous thrombosis, but its clinical significance is uncertain because of conflicting studies. Further research is required to understand the physiology behind thrombocytosis in Gemcitabine-treated patients. Fluctuations between thrombocytosis and thrombocytopenia need to be closely monitored. Management for Gemcitabine-induced thrombocytosis can be improved if more comprehensive studies are undertaken to explore the role of thrombocytosis in cardiovascular events.

Association of vitamin deficiency with the progression of anaemia

Vitamins are micronutrients that play a vital role in the body’s proper functioning and development. Furthermore, they are an essential requirement of the body for producing red blood cells (RBCs) and their growth. A particular quantity of micronutrients is mandatory for the regulation of body metabolism. Deficiency in vitamins leads to different types of anaemia in the body. Furthermore, deficiencies in both fat-soluble and water-soluble vitamins are linked to the destruction of RBCs. This review article was aimed at finding the correlation between the deficiency of vitamins and anaemia, with a major focus on the deficiency of vitamins B-9 and B-12 and their association with anaemia. In our deep observation of the literature, we found that the deficiency of vitamins causes iron malabsorption, haemoglobin (Hb) synthesis malfunctioning, impaired DNA synthesis, and a disturbed methylation cycle, while a disrupted erythropoiesis process and a reduction in the RBC’s production leads to anaemia. Interference in vitamin B-9 and vitamin B-12-associated chemical reactions causes deficiency and results in diminished DNA synthesis. Malabsorption of vitamins B-9 and B-12 is a major concern for anaemia, but other water and fat-soluble vitamins disrupt iron metabolism and interrupt the erythropoiesis process, which ultimately causes anaemia. There should be a balanced number of vitamins in the diet; otherwise, this will inhibit the production of RBCs. As Vitamin B-9 and B-12 deficiencies have been associated with a reduction in DNA synthesis, further study is required to discover how additional fat-soluble and water-soluble vitamins affect DNA synthesis.

Design, docking optimization, and evaluation of biotin-PEG4-1,8-naphthalimide as a potent and safe antitumor agent with dual targeting of ferroptosis and DNA.

A set of biotin-polyethylene glycol (PEG)-naphthalimide derivatives 4a-4h with dual targeting of ferroptosis and DNA were designed and optimized using docking simulation as antitumor agents. Docking simulation optimization results indicated that biotin-PEG4-piperazine-1,8-naphthalimide 4d should be the best candidate among these designed compounds 4a-4h, and therefore, we synthesized and evaluated it as a novel antitumor agent. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and MGC-803 and U251 xenograft models identified 4d as a good candidate antitumor agent with potent efficacy and safety profiles, compared with amonafide and temozolomide. The findings of the docking simulations, fluorescence intercalator displacement (FID), western blot, comet, 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, transmission electron microscopy, and BODIPY-581/591-C11, FerroOrange, and dihydroethidium (DHE) fluorescent probe assays revealed that 4d could induce DNA damage, affect DNA synthesis, and cause cell cycle arrest in the S phase in MGC-803 cells. Also, it could induce lipid peroxidation and thus lead to ferroptosis in MGC-803 cells, indicating that it mainly exerted antitumor effects through dual targeting of ferroptosis and DNA. These results suggested that it was feasible to design, optimize using docking simulation, and evaluate the potency and safety of biotin-PEG-1,8-naphthalimide as a antitumor agent with dual targeting of ferroptosis and DNA, based on a multi-target drug strategy.

Design, synthesis, and biological evaluation of harmine derivatives as topoisomerase I inhibitors for cancer treatment

A series of β-carboline derivatives were designed and synthesized by introducing the chalcone moiety into the harmine. The synthesized derivatives were evaluated their anti-proliferative activities against six human cancer cell lines (MCF-7, MDA-MB-231, HepG2, HT29, A549, and PC-3) and one normal cell line (L02). Among them, compound G11 exhibited the potent anti-proliferative activity against MCF-7 cell line, with an IC50 value of 0.34 μM. Further biological studies revealed that compound G11 inhibited colony formation of MCF-7 cells, suppressed MCF-7 cell migration by downregulating migration-associated protein MMP-2. In addition, it could induce apoptosis of MCF-7 cells by downregulating Bcl-2 and upregulating Cleaved-PARP, Bax, and phosphorylated Bim proteins. Furthermore, compound G11 can act as a Topo I inhibitor, affecting DNA synthesis and transcription, thereby inhibiting cancer cell proliferation. Moreover, compound G11 inhibited tumor growth in 4T1 syngeneic transplant mice with an inhibition rate of 43.19 % at a dose of 10 mg/kg, and 63.87 % at 20 mg/kg, without causing significant toxicity to the mice or their organs, achieving the goal of reduced toxicity and increased efficacy. All these results indicate of G11 has enormous potential as an anti-tumor agent and merits further investigation.

A new cyclodipeptide from Tetragonisca angustula honey active against Neospora caninum and in silico study

A new cyclic natural compound formed by succinic acid and two alanine amino acid units was isolated from the Tetragonisca angustula honey extract. The chemical structure of 1 was established based on spectroscopic data analysis, including one- (1H and 13C NMR) and two-dimensional NMR techniques (1H-1H-COSY, HSQC and HMBC). A primary culture model previously infected with Neospora caninum was used to evaluate 1 for two time intervals (24 and 72 h), showing a reduction (40-56%) of the number of tachyzoites in the first 24 h and until 72 h, a dose-dependent reduction in parasite proliferation (25-50%). Glial cells treated with 1 did not demonstrate toxicity at concentrations up to 25 ug/mL. Treated and infected cultures showed an increase in NO when compared to control cells in 24 h and 72 h. In silico studies suggest that the new compound may affect DNA synthesis and impair ­protein production.

A pan-cancer analysis of SLC1A5 in human cancers

BackgroundThe alanine-serine-cysteine transporter 2, ASCT2 (solute carrier family 1 member 5, SLC1A5), is a major transporter of the amino acid, glutamine. Although SLC1A5 has been reported to be associated with some types of cancer, less pan-cancer analysis, which would give a comprehensive understanding of SLC1A5 across human cancers, has been carried out. MethodsWe used the TCGA and GEO databases to investigate the oncogenic role of SLC1A5. We examined gene and protein expression, survival, genetic mutations, protein phosphorylation, immunocyte infiltration and the related genes correlated pathways. In HCT116 cells, SLC1A5 was silenced by siRNAs and the mRNA and protein was checked by Q-PCR and WB, respectively and the cellular function was assessed by CCK8, cell cycle and apoptosis. ResultsWe found that SLC1A5 was over-expressed in multiple types of cancer and that elevated expression of SLC1A5 was associated with poor survival in many cancers. The missense mutation of R330 H/C was associated with poor survival, especially in uterine carcinosarcoma. Furthermore, we found enhanced phosphorylation of S503 in uterine corpus endometrial carcinoma and lung adenocarcinoma. In addition, elevated SLC1A5 expression was associated with immune cell infiltration in many cancers. KEGG and GO analysis showed that SLC1A5 and its related genes were involved in central carbon metabolism in cancer, due to their amino acid transport activity. The cellular function indicated that SLC1A5 may influence the cell proliferation by affecting DNA synthesis. ConclusionsOur findings highlighted the important role of SLC1A5 in tumorigenesis and provided insights into potential cancer treatment strategies.

Synergistic Effect of SOS Response and GATC Methylome Suppression on Antibiotic Stress Survival in Escherichia coli.

The suppression of the SOS response has been shown to enhance the in vitro activity of quinolones. Furthermore, Dam-dependent base methylation has an impact on susceptibility to other antimicrobials affecting DNA synthesis. Here, we investigated the interplay between these two processes, alone and in combination, in terms of antimicrobial activity. A genetic strategy was used employing single- and double-gene mutants for the SOS response (recA gene) and the Dam methylation system (dam gene) in isogenic models of Escherichia coli both susceptible and resistant to quinolones. Regarding the bacteriostatic activity of quinolones, a synergistic sensitization effect was observed when the Dam methylation system and the recA gene were suppressed. In terms of growth, after 24 h in the presence of quinolones, the Δdam ΔrecA double mutant showed no growth or delayed growth compared to the control strain. In bactericidal terms, spot tests showed that the Δdam ΔrecA double mutant was more sensitive than the ΔrecA single mutant (about 10- to 102-fold) and the wild type (about 103- to 104-fold) in both susceptible and resistant genetic backgrounds. Differences between the wild type and the Δdam ΔrecA double mutant were confirmed by time-kill assays. The suppression of both systems, in a strain with chromosomal mechanisms of quinolone resistance, prevents the evolution of resistance. This genetic and microbiological approach demonstrated the enhanced sensitization of E. coli to quinolones by dual targeting of the recA (SOS response) and Dam methylation system genes, even in a resistant strain model.

Methylenetetrahydrofolate reductase (MTHFR) 677C>T polymorphisms in breast cancer: A Filipino preliminary case-control study

Single nucleotide polymorphisms (SNP) present in folate metabolic enzymes, such as methylenetetrahydrofolate reductase (MTHFR), affect DNA synthesis and methylation processes that can lead to cancer development. Several studies suggest that MTHFR SNP is associated with breast cancer risk, particularly among Asian populations. Thus, this study determined the association of MTHFR 677C>T SNP with breast cancer risk in selected Filipino population. DNA samples from breast cancer cases (n = 100) and clinically healthy controls (n = 100) were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The differences in MTHFR genotype and allele frequencies were evaluated by computing for the odds ratio (OR) with a 95 % confidence interval (CI). The CT genotype (OR: 0.775, 95 % CI: 0.35–1.71, p = 0.53), T allele (OR: 0.703, 95 % CI: 0.34–1.48, p = 0.35), and presence of at least one T allele (ORCT+TT: 0.729, 95 % CI: 0.33–1.60, p = 0.43) were not associated with breast cancer risk. Based on the SNP interaction with other risk factors, no significant difference (p > 0.05) was observed for the tumor characteristics, menarche age, and menopause age. Interestingly, a decreased risk (OR: 0.342, 95 % CI: 0.14–0.84, p = 0.019) was observed for the CC genotype in individuals who consumed dietary fibers. Meanwhile, there was an increased risk for passive smokers with the CC genotype (OR: 6.31, 95 % CI: 2.68–14.9, p < 0.001). Overall, the MTHFR 677C>T was not significantly associated with breast cancer risk in a selected Filipino population. Since this study involved a relatively small number of participants, increasing the number of samples is recommended for a more conclusive test of association of MTHFR 677C>T with breast cancer risk in Filipinos.

Rat prostate tumors induce DNA synthesis in remote organs

Advanced cancers induce systemic responses. However, if such systemic changes occur already when aggressive tumors are small, have not been thoroughly characterized. Here, we examined how localized prostate cancers of different sizes and metastatic potential affected DNA synthesis in the rest of the prostate and in various remote organs. Non-metastatic Dunning R-3327 G (G) tumor cells, metastatic MatLyLu (MLL) tumor cells, or vehicle were injected into the prostate of immunocompetent rats. All animals received daily injections of Bromodeoxyuridine (BrdU), to label cells/daughter cells with active DNA synthesis. Equal sized G- and MLL-tumors, similarly increased BrdU-labeling in the prostate, lymph nodes and liver compared to tumor-free controls. Prior to metastasis, MLL-tumors also increased BrdU-labeling in bone marrow and lungs compared to animals with G-tumors or controls. In animals with MLL-tumors, BrdU-labeling in prostate, lungs, brown adipose tissue and skeletal muscles increased in a tumor-size-dependent way. Furthermore, MLL-tumors induced increased signs of DNA damage (γH2AX staining) and accumulation of CD68 + macrophages in the lungs. In conclusion, small localized prostate cancers increased DNA synthesis in several remote tissues in a tumor type- and size-dependent way. This may suggest the possibility for early diagnosis of aggressive prostate cancer by examining tumor-induced effects in other tissues.

Antitumor Mechanism of Hydroxycamptothecin via the Metabolic Perturbation of Ribonucleotide and Deoxyribonucleotide in Human Colorectal Carcinoma Cells.

Hydroxycamptothecin (SN38) is a natural plant extract isolated from Camptotheca acuminate. It has a broad spectrum of anticancer activity through inhibition of DNA topoisomerase I, which could affect DNA synthesis and lead to DNA damage. Thus, the action of SN38 against cancers could inevitably affect endogenous levels of ribonucleotide (RNs) and deoxyribonucleotide (dRNs) that play critical roles in many biological processes, especially in DNA synthesis and repair. However, the exact impact of SN38 on RNs and dRNs is yet to be fully elucidated. In this study, we evaluated the anticancer effect and associated mechanism of SN38 in human colorectal carcinoma HCT 116 cells. As a result, SN38 could decrease the cell viability and induce DNA damage in a concentration-dependent manner. Furthermore, cell cycle arrest and intracellular nucleotide metabolism were perturbed due to DNA damage response, of which ATP, UTP, dATP, and TTP may be the critical metabolites during the whole process. Combined with the expression of deoxyribonucleoside triphosphates synthesis enzymes, our results demonstrated that the alteration and imbalance of deoxyribonucleoside triphosphates caused by SN38 was mainly due to the de novo nucleotide synthesis at 24 h, and subsequently the salvage pathways at 48 h. The unique features of SN38 suggested that it might be recommended as an effective supplementary drug with an anticancer effect.

Cytokines Involved in the Progression of Liver Fibrosis by Influencing DNA Synthesis

Liver fibrosis is a pathological change in which the connective tissue in the liver proliferates abnormally, resulting in abnormal liver function or structure. Long-term liver fibrosis can develop cirrhosis or liver cancer, which poses a great threat to human health. This article reviews the cytokines closely related to liver fibrosis in recent years These cytokines affect the development of liver fibrosis mainly through processes that affect DNA synthesis. Platelet-derived growth factor promotes the division and proliferation of hepatic stellate cells by stimulating cellular DNA synthesis. Insulin-like growth factor, on the other hand, shows the proliferation of myofibroblastic cells in a manner that promotes the cell cycle to enter the DNA synthesis phase. Interleukin-6 promotes the progression of DNA synthesis in a manner that activates cyclins. We aim to find new approaches for the treatment of liver fibrosis by means of regulating DNA synthesis as the main approach by summarizing existing studies.

The Contribution of Lysosomes to DNA Replication.

Lysosomes, acidic, membrane-bound organelles, are not only the core of the cellular recycling machinery, but they also serve as signaling hubs regulating various metabolic pathways. Lysosomes maintain energy homeostasis and provide pivotal substrates for anabolic processes, such as DNA replication. Every time the cell divides, its genome needs to be correctly duplicated; therefore, DNA replication requires rigorous regulation. Challenges that negatively affect DNA synthesis, such as nucleotide imbalance, result in replication stress with severe consequences for genome integrity. The lysosomal complex mTORC1 is directly involved in the synthesis of purines and pyrimidines to support DNA replication. Numerous drugs have been shown to target lysosomal function, opening an attractive avenue for new treatment strategies against various pathologies, including cancer. In this review, we focus on the interplay between lysosomal function and DNA replication through nucleic acid degradation and nucleotide biosynthesis and how these could be exploited for therapeutic purposes.

Inhibition of the mRNA-Binding Protein IGF2BP1 Suppresses Proliferation and Sensitizes Neuroblastoma Cells to Chemotherapeutic Agents.

Gain at chromosome 17q21 in neuroblastoma is associated with a poor prognosis, independent of MYCN amplification status. Several potential proto-oncogenes have been identified in this region, one of them—insulin-like growth-factor-2 mRNA binding protein (IGF2BP1)—is expressed at high levels in stage 4 tumors, and associated with overall lower patient survival. Here, we demonstrate that down-regulation of IGF2BP1 activity, either by transcript silencing or chemical inhibition, suppresses neuroblastoma cell growth. Furthermore, the combination of IGF2BP1 inhibition along with commonly used chemotherapeutics that broadly affect DNA synthesis, or cyclin-dependent kinase (CDK) inhibitors that disrupt signal transduction, have a synergistic effect on the suppression of neuroblastoma cell proliferation.

Increasing the greenness of an organic acid through deep eutectic solvation and further polymerisation

Acrylic acid (AA) is an important and widely used industrial chemical, but its high toxicity renders its use incompatible with the concept of green development. By leveraging its terminal carboxyl group and unsaturated bond, we designed and explored a new strategy to increase the greenness of AA via its eutectic melting using a quaternary ammonium salt (choline chloride) to form a deep eutectic solvent (DES), followed by polymerisation of the DES to form a polymer (poly(DES)). The greenness of AA, DES, and poly(DES) was evaluated via an in vitro test using MGC80-3 cells and an in vivo test using Kunming mice. The toxicity improved from Grade 2 (moderately toxic) for AA to Grade 1 (slightly toxic) for DESs and Grade 0 (non-toxic) for poly(DES) in the in vitro test. Moreover, the poly(DES)s showed a lower toxicity in mice than the DESs in the in vivo test. Thus, greenness enhancement was successfully achieved, with the greenness following the order AA < DES < poly(DES). Furthermore, the mechanisms underlying the change in toxicity were explored through microscopy and flow cytometry, which revealed that the DES can permeate the MGC80-3 cell membrane during the G0/G1 phase to adversely affect DNA synthesis in the S phase, but the poly(DES) cannot. Finally, the green poly(DES), which showed good adsorption properties and flexible functionality, was successfully applied as a carrier or excipient of drugs. Through the novel strategy reported herein, greenness enhancement and the broadening of the application scope of a toxic organic acid were achieved, making such acids applicable for green development.

The reversible reproductive toxicity of 5-fluorouracil in mice

5-Fluorouracil (5-FU) is a “cytotoxic” drug used for cancer chemotherapy, which inhibits cells division via affecting DNA synthesis. Although being widely used for cancer treatment, 5-FU has non-negligible side effects. In the present study, the effects of 5-FU on oocyte and early embryonic development were investigated. Multiple intraperitoneal administration of 5-FU (50 mg/kg/day) in female mice resulted in small ovarian size and reduced number of corpus luteum in the ovary, and lead to ovulation failure. However, these defects could be recovered after one week. In vitro experiments further indicated that exposure to 5-FU inhibited oocytes maturation and reduced developmental potential of pre-implantation embryos. Our data suggested that 5-FU has negative impact on ovarian function, oocyte and early embryonic development, but the adverse effect could be reversed after withdrawal of 5-FU administration.

Electron beam irradiation induces DNA endoreplication in holometabolous juvenile insects: a rapid flow cytometry-based diagnosis

Ionizing radiation including electron beam (eBeam) technology has been used as a quarantine measure around the world for transboundary shipment of agricultural products. Since the treatment goal of this technology is not to instantly kill insects but to cause them to be sterile, an apparent challenge is how to ensure that the agricultural commodities have been exposed to ionizing radiation if live insects are found. Because irradiation affects DNA synthesis and cell division, we investigated the feasibility of using flow cytometry detection of eBeam irradiation-induced ploidy change as a diagnostic tool. All eBeam-treated holometabolous insects tested including cowpea bruchid (Callosobruchus maculatus), corn earworm (Helicoverpa zea) and fruit fly (Drosophila melanogaster) displayed significantly higher proportions of polyploid cells than their respective unirradiated controls. However, such increased DNA ploidy was mostly absent in irradiated hemimetabolous sand field cricket (Gryllus firmus), green peach aphid (Myzus persicae) and potato/tomato psyllid (Bactericera cockerelli). Further studies with representative holometabolous insects revealed that the eBeam-triggered DNA endoreplicative response was strong in larvae, but became weaker as insects continued to develop into pupae and was even diminished in adults. Therefore, the flow cytometry-based method has the potential to be developed into a diagnostic tool to determine whether juvenile insects found on agricultural shipments, particularly those that undergo complete metamorphosis, have received irradiation as a quarantine treatment. This simple and rapid detection method could potentially resolve the dilemma that occurs in border control and domestic movement of plant material and products from areas under quarantine.

Alkaloids as Anticancer Agents: A Review of Chinese Patents in Recent 5 Years.

In recent years, many novel alkaloids with anticancer activity have been found in China, and some of them are promising for developing as anticancer agents. This review aims to provide a comprehensive overview of the information about alkaloid anticancer agents disclosed in Chinese patents, and discusses their potential to be developed as anticancer drugs used clinically. Anticancer alkaloids disclosed in Chinese patents in recent 5 years were presented according to their mode of actions. Their study results published on PubMed, and SciDirect databases were presented. More than one hundred anticancer alkaloids were disclosed in Chinese patents and their mode of action referred to arresting cell cycle, inhibiting protein kinases, affecting DNA synthesis and p53 expression, etc. Conclusion: Many newly found alkaloids displayed potent anticancer activity both in vitro and in vivo, and some of the anticancer alkaloids acted as protein kinase inhibitors or CDK inhibitors possess the potential for developing as novel anticancer agents.

3\u2019UTR polymorphism of Thymidylate Synthase gene increased the risk of persistence of pre-neoplastic cervical lesions

BackgroundCervical cancer is caused by high-risk Human Papillomavirus (hr-HPV) infection associated with cofactors that has been analyzed as predictors of the remission or persistence of cytological abnormalities remission or persistence. These cofactors can be either environmental, epigenetic, or genetic. Polymorphism in genes of enzymes that act on one-carbon metabolism alter their activity and also may be associated with cervical carcinogenesis because they affect DNA synthesis and repair, and gene expression. Therefore, this study aimed to analyze the risk of persistence of pre-neoplastic cervical lesions according to genetic polymorphisms involved in one-carbon metabolism.MethodsOur sample consisted of 106 women, divided into two groups – Remission (n = 60), i.e., with the presence of pre-neoplastic lesions at first meeting (T1) and normal cytology after 6 months of follow-up (T2), and Persistence (n = 46), i.e., with the presence of pre-neoplastic lesions at T1 and T2. We obtained cervical samples for cytological analysis (T1 and T2), HPV detection (T1), and evaluation of polymorphism C667T of Methylenetetrahydrofolate Reductase (MTHFR C677T), A2756G of Methionine Synthase (MS A2756G), A66G of Methionine Synthase Reductase (MTRR A66G), double or triple 28 bp tandem repeat in 5′-untranslated enhanced region of Thymidylate Synthase (TSER), and 6 bp deletion at nucleotide 1494 in TS 3′-untranslated region (TS3’UTR). To analyze all genetic polymorphisms simultaneously, we calculated the Genetic Risk Score (GRS).ResultsWe observed no differences between the Remission and Persistence groups regarding the GRS. Also, there were no differences in the genotypic and allelic distribution of MTHFR C677T and MS A2756G polymorphisms. However, the risk of persistence was higher among women with the heterozygote genotype - ins/del [OR (IC95%): 3.22 (1.19–8.69), p = 0.021], or the polymorphic genotype – del/del [OR (IC95%): 6.50 (1.71–24.70), p = 0.006] of TS3’UTR. Conclusions: The presence of the TS3’UTR polymorphism increased the risk of persistence of cervical abnormalities. This genetic variant could be a potential marker of cervical carcinogenesis and therefore assist the follow-up of women with persistent pre-neoplastic cervical lesions.

Updates on human equilibrative nucleoside transporter 1 in neoplastic diseases

The human equilibrative nucleoside transporter 1(hENT1)is a multi-integrated membrane protein that mediates the transport of nucleosides, nucleobases and nucleoside analogs.It is mainly distributed on the cell membrane in humans.hENT1 maintains the homeostasis of cells and the intracellular concentration of nucleoside drugs through facilitating diffusion, thereby affecting DNA and RNA synthesis, cell signaling, metabolic regulation and tumor chemotherapy.This article reviews the progress in the structure and function of hENT1, the distribution in tumor tissues, the nucleoside analogs response and the prognosis of neoplastic diseases. Key words: Human equilibrative nucleoside transporter 1; Nucleoside analogs; Neoplasm

Gram-negative synergy and mechanism of action of alkynyl bisbenzimidazoles

Bisbenzimidazoles with terminal alkynyl linkers, selective inhibitors of bacterial topoisomerase I, have been evaluated using bacterial cytological profiling (BCP) to ascertain their mechanism of action and screened for synergism to improve Gram-negative bacterial coverage. Principal component analysis of high throughput fluorescence images suggests a dual-mechanism of action affecting DNA synthesis and cell membrane integrity. Fluorescence microscopy of bacteria challenged with two of the alkynyl-benzimidazoles revealed changes in the cellular ultrastructure that differed from topoisomerase II inhibitors including induction of spheroplasts and membrane lysis. The cytoskeleton recruitment enzyme inhibitor A22 in combination with one of the alkynyl-benzimidazoles was synergistic against Acinetobacter baumannii and Escherichia coli. Gram-positive coverage remained unchanged in the A22-alkynyl bisbenzimidazole combination. Efflux inhibitors were not synergistic, suggesting that the Gram-negative outer membrane was a significant barrier for alkynyl-bisbenzimidazole uptake. Time-kill assays demonstrated the A22-bisbenzimidazole combination had a similar growth inhibition curve to that of norfloxacin in E.coli. Bisbenzimidazoles with terminal alkynyl linkers likely impede bacterial growth by compromising cell membrane integrity and by interfering with DNA synthesis against Gram-positive pathogens and in the synergistic combination against Gram-negative pathogens including E. coli and multidrug-resistant A. baumanii.