Frentizole, a Nontoxic Immunosuppressive Drug, and Its Analogs Display Antitumor Activity via Tubulin Inhibition

Antimitotic agents are one of the more successful types of anticancer drugs, but they suffer from toxicity and resistance. The application of approved drugs to new indications (i.e., drug repurposing) is a promising strategy for the development of new drugs. It relies on finding pattern similarities: drug effects to other drugs or conditions, similar toxicities, or structural similarity. Here, we recursively searched a database of approved drugs for structural similarity to several antimitotic agents binding to a specific site of tubulin, with the expectation of finding structures that could fit in it. These searches repeatedly retrieved frentizole, an approved nontoxic anti-inflammatory drug, thus indicating that it might behave as an antimitotic drug devoid of the undesired toxic effects. We also show that the usual repurposing approach to searching for targets of frentizole failed in most cases to find such a relationship. We synthesized frentizole and a series of analogs to assay them as antimitotic agents and found antiproliferative activity against HeLa tumor cells, inhibition of microtubule formation within cells, and arrest at the G2/M phases of the cell cycle, phenotypes that agree with binding to tubulin as the mechanism of action. The docking studies suggest binding at the colchicine site in different modes. These results support the repurposing of frentizole for cancer treatment, especially for glioblastoma.

[Risk of thrombosis recurrence among patients with COVID-19- and surgery-associated venous thromboembolism]

Introduction

Recent surgery is a well-known major transient risk factor for venous thromboembolism (VTE) due to the low risk of VTE recurrence after anticoagulation is discontinued. On the other hand, the risk of VTE recurrence among patients with COVID-19-associated VTE is unknown. This study aimed to compare the risk of VTE recurrence between patients with COVID-19- and surgery-associated VTE.

Methods

A prospective observational single-center study was performed including consecutive patients diagnosed with VTE in a tertiary hospital from January 2020 to May 2022 and followed up for at least 90 days. Baseline characteristics, clinical presentation, and outcomes were assessed. The incidence of VTE recurrence, bleeding, and death was compared between both groups.

Results

A total of 344 patients were included in the study: 111 patients with surgery-associated VTE and 233 patients with COVID-19-associated VTE. Patients with COVID-19-associated VTE were more frequently men (65.7% vs 48.6%, p = 0.003). VTE recurrence was 3% among COVID-19 patients and 5.4% among surgical patients, with no significant differences (p = 0.364). The incidence rate of recurrent VTE was 1.25 per 1000 person-months in COVID-19 patients and 2.29 person-months in surgical patients, without significant differences (p = 0.29). In the multivariate analysis, COVID-19 was associated with higher mortality (HR 2.34; 95% CI 1.19-4.58), but not with a higher risk of recurrence (HR 0.52; 95% CI 0.17-1.61). No differences were found in recurrence in the multivariate competing risk analysis (SHR 0.82; 95% CI 0.40 - 2.05).

Conclusions

In patients with COVID-19 and surgery-associated VTE, the risk of recurrence was low, with no differences between both groups.