Identification of a novel DNA repair inhibitor using an in silico driven approach shows effective combinatorial activity with genotoxic agents against multidrug-resistant Escherichia coli.

Increasing antimicrobial drug resistance represents a global existential threat. Infection is a particular problem in immunocompromised individuals, such as patients undergoing cancer chemotherapy, due to the targeting of rapidly dividing cells by antineoplastic agents. We recently developed a strategy that targets bacterial nucleotide excision DNA repair (NER) to identify compounds that act as antimicrobial sensitizers specific for patients undergoing cancer chemotherapy. Building on this, we performed a virtual drug screening of a ~120,000 compound library against the key NER protein UvrA. From this, numerous target compounds were identified and of those a candidate compound, Bemcentinib (R428), showed a strong affinity toward UvrA. This NER protein possesses four ATPase sites in its dimeric state, and we found that Bemcentinib could inhibit UvrA's ATPase activity by ~90% and also impair its ability to bind DNA. As a result, Bemcentinib strongly diminishes NER's ability to repair DNA in vitro. To provide a measure of in vivo activity we discovered that the growth of Escherichia coli MG1655 was significantly inhibited when Bemcentinib was combined with the DNA damaging agent 4-NQO, which is analogous to UV. Using the clinically relevant DNA-damaging antineoplastic cisplatin in combination with Bemcentinib against the urological sepsis-causing E. coli strain EC958 caused complete growth inhibition. This study offers a novel approach for the potential development of new compounds for use as adjuvants in antineoplastic therapy.

Developing novel antimicrobials by combining cancer chemotherapeutics with bacterial DNA repair inhibitors.

Cancer chemotherapeutics kill rapidly dividing cells, which includes cells of the immune system. The resulting neutropenia predisposes patients to infection, which delays treatment and is a major cause of morbidity and mortality. To tackle this problem, we have isolated several compounds that inhibit bacterial DNA repair, alone they are non-toxic, however in combination with DNA damaging anti-cancer drugs, they prevent bacterial growth. These compounds were identified through screening of an FDA-approved drug library in the presence of the anti-cancer compound cisplatin. Using a series of triage tests, the screen was reduced to a handful of drugs that were tested for specific activity against bacterial nucleotide excision DNA repair (NER). Five compounds emerged, of which three possess promising antimicrobial properties including cell penetrance, and the ability to block replication in a multi-drug resistant clinically relevant E. coli strain. This study suggests that targeting NER could offer a new therapeutic approach tailor-made for infections in cancer patients, by combining cancer chemotherapy with an adjuvant that targets DNA repair.

Identification of the target and mode of action for the prokaryotic nucleotide excision repair inhibitor ATBC.

In bacteria, nucleotide excision repair (NER) plays a major role in repairing DNA damage from a wide variety of sources. Therefore, its inhibition offers potential to develop a new antibacterial in combination with adjuvants, such as UV light. To date, only one known chemical inhibitor of NER is 2-(5-amino-1,3,4-thiadiazol-2-yl)benzo(f)chromen-3-one (ATBC) exists and targets Mycobacterium tuberculosis NER. To enable the design of future drugs, we need to understand its mechanism of action. To determine the mechanism of action, we used in silico structure-based prediction, which identified the ATP-binding pocket of Escherichia coli UvrA as a probable target. Growth studies in E. coli showed it was nontoxic alone, but able to impair growth when combined with DNA-damaging agents, and as we predicted, it reduced by an approximately 70% UvrA's ATPase rate. Since UvrA's ATPase activity is necessary for effective DNA binding, we used single-molecule microscopy to directly observe DNA association. We measured an approximately sevenfold reduction in UvrA molecules binding to a single molecule of dsDNA suspended between optically trapped beads. These data provide a clear mechanism of action for ATBC, and show that targeting UvrA's ATPase pocket is effective and ATBC provides an excellent framework for the derivation of more soluble inhibitors that can be tested for activity.

Long-Term Functional Outcomes After Surgical Correction of Congenital Penile Curvature.

OBJECTIVES: To present the surgical results and the functional outcomes after surgical correction of congenital penile curvature (CPC) by different plication techniques. METHODS: All consecutive patients operated for CPC from 2010 to 2019 in a university hospital of Lyon, France, were retrospectively identified and included for analyzing surgical results. They were proposed to answer a questionnaire (between January 2020 and May 2020) that included questions of the Peyronie's Disease Questionnaire (PDQ), the Erection Hardness Score (EHS), and the Internal Index of Erectile Function (IIEF5), along with non-validated specific questionnaires. RESULTS: A total of 31 patients were included, their mean (SD) age was 21.2 (4.9) years, their mean (SD) follow-up of 55.5 (33.7) months. The principal curvature was ventral for 25 (80.6%) patients. After the surgery, 28 (90.3%) patients had straight penis or a residual curvature less than 15°, and 2 (6.5%) required a second surgery. A total of 23 (74.2%) patients answered the post-operative questionnaire. The mean (SD) scores were 1.2/16 (1.8) for PDQ-Bothered Score, 1.5/24 (2.1) for PDQ Psychological and Physical, and 1.7/30 (2.7) for PDQ pain. The mean (SD) IIEF5 was 22.7/25 (4.6). All patients had an EHS of 4/4. There were 10 patients who never had sexual intercourse before the surgery and 4 who still had not when answering the questionnaire. All patients (23/23) were either "satisfied" or "very satisfied" with the outcomes of the operation, and 13 (56.5%) reported improvement of their sexual life after surgery. CONCLUSION: This study confirmed the favorable outcomes of surgical plication for CPC with low morbidity. A concomitant sexological care may be useful for some patients.