Aldehyde Dehydrogenase Inhibitor Research Articles

A putative role for ALDH inhibitors and chemoprevention of BRCA-mutation-driven tumors

Aldehyde dehydrogenase (ALDH) enzymatic activity is a marker of cancer-initiating cells (CIC) in many tumor types. Our group and others have found that ALDH1A family inhibitors (ALDHi) can preferentially induce death of ovarian CIC in established ovarian cancer. We sought to determine if ALDHi, by targeting CIC at the time of tumor initiation, could function as a chemopreventive for ovarian cancer. As BRCA1/2 mutation carriers represent a population who could benefit from an ovarian cancer chemopreventive, we focused on BRCA mutation-associated tumor cell lines and murine tumor models. We found that, compared to BRCA wild-type cells, BRCA mutant ovarian cancer cells are more sensitive to the ALDHi673A. Similarly, while 673A treatment of wild-type fallopian tube epithelial (FTE) cells is non-toxic, 673A induces death in FTE cells with BRCA1 knockdown. Using a murine fallopian tube organoid model of ovarian carcinogenesis, we show that 673A reduced organoid complexity and significantly reduce colony formation of BRCA-mutant cells. Organoids that persisted after 673A treatment were predominantly BRCA1wt, but NF1 mutant, suggesting a resistance mechanism. Finally, using the BPRN (Brca1, Trp53, Rb1, Nf1 inactivated) mouse model of tubo-ovarian cancer, we evaluated the impact of intermittent 673A therapy on carcinogenesis. 673A treatment resulted in a significant reduction in serous tubal intraepithelial carcinoma (STIC) lesions and carcinomas. Collectively, the findings suggest that ALDHi, such as 673A, could serve as chemopreventive agents for BRCA1/2 mutation carriers.

The Relationship between Antibiotics and Disulfiram-like Reaction

Drinking without antibiotics has become the consensus of more and more people. On this phenomenon this paper will introduce the principle of this. The article will briefly introduce the structure of the medication principle and partial historical development. Partial historical development of two different kinds of mainstream antibiotics, cephalosporin and metronidazole. Understand these two mainstream antibiotics from scratch, and understand the principle of the reason why we cannot have them with alcohol fundamentally. Furthermore, the article will briefly analyze the principle and phenomenon of the same side reaction produced by two antibiotics with different structures, namely, a disulfiramlike reaction, to explain and show what will happen if people have these two kinds of antibiotics after drinking the alcohol. In this way, this work will popularize the hazards and precautions of drug use after drinking to more nonprofessionals

Advancing Cancer Therapy with Copper/Disulfiram Nanomedicines and Drug Delivery Systems.

Disulfiram (DSF) is a thiocarbamate based drug that has been approved for treating alcoholism for over 60 years. Preclinical studies have shown that DSF has anticancer efficacy, and its supplementation with copper (CuII) significantly potentiates the efficacy of DSF. However, the results of clinical trials have not yielded promising results. The elucidation of the anticancer mechanisms of DSF/Cu (II) will be beneficial in repurposing DSF as a new treatment for certain types of cancer. DSF's anticancer mechanism is primarily due to its generating reactive oxygen species, inhibiting aldehyde dehydrogenase (ALDH) activity inhibition, and decreasing the levels of transcriptional proteins. DSF also shows inhibitory effects in cancer cell proliferation, the self-renewal of cancer stem cells (CSCs), angiogenesis, drug resistance, and suppresses cancer cell metastasis. This review also discusses current drug delivery strategies for DSF alone diethyldithocarbamate (DDC), Cu (II) and DSF/Cu (II), and the efficacious component Diethyldithiocarbamate-copper complex (CuET).

Identification and characterisation of the tegument-expressed aldehyde dehydrogenase SmALDH_312 of Schistosoma mansoni, a target of disulfiram.

Schistosomiasis is an infectious disease caused by blood flukes of the genus Schistosoma and affects approximately 200 million people worldwide. Since Praziquantel (PZQ) is the only drug for schistosomiasis, alternatives are needed. By a biochemical approach, we identified a tegumentally expressed aldehyde dehydrogenase (ALDH) of S. mansoni, SmALDH_312. Molecular analyses of adult parasites showed Smaldh_312 transcripts in both genders and different tissues. Physiological and cell-biological experiments exhibited detrimental effects of the drug disulfiram (DSF), a known ALDH inhibitor, on larval and adult schistosomes in vitro. DSF also reduced stem-cell proliferation and caused severe tegument damage in treated worms. In silico-modelling of SmALDH_312 and docking analyses predicted DSF binding, which we finally confirmed by enzyme assays with recombinant SmALDH_312. Furthermore, we identified compounds of the Medicine for Malaria Venture (MMV) pathogen box inhibiting SmALDH_312 activity. Our findings represent a promising starting point for further development towards new drugs for schistosomiasis.

Targeting aldehyde dehydrogenase enzymes in combination with chemotherapy and immunotherapy: An approach to tackle resistance in cancer cells.

Modern cancer chemotherapy originated in the 1940s, and since then, many chemotherapeutic agents have been developed. However, most of these agents show limited response in patients due to innate and acquired resistance to therapy, which leads to the development of multi-drug resistance to different treatment modalities, leading to cancer recurrence and, eventually, patient death. One of the crucial players in inducing chemotherapy resistance is the aldehyde dehydrogenase (ALDH) enzyme. ALDH is overexpressed in chemotherapy-resistant cancer cells, which detoxifies the generated toxic aldehydes from chemotherapy, preventing the formation of reactive oxygen species and, thus, inhibiting the induction of oxidative stress and the stimulation of DNA damage and cell death. This review discusses the mechanisms of chemotherapy resistance in cancer cells promoted by ALDH. In addition, we provide detailed insight into the role of ALDH in cancer stemness, metastasis, metabolism, and cell death. Several studies investigated targeting ALDH in combination with other treatments as a potential therapeutic regimen to overcome resistance. We also highlight novel approaches in ALDH inhibition, including the potential synergistic employment of ALDH inhibitors in combination with chemotherapy or immunotherapy against different cancers, including head and neck, colorectal, breast, lung, and liver.

Cefotaxime: A Reappraisal in Lower Respiratory Tract Infections

Lower respiratory Tract Infection (LRTI) is one of the fourth most common cause of mortality across the globe, and constitutes to be a major portion in critically ill patients associated with prolonged hospitalisation. Apart from age factor, other risk factors which predispose to the LRTI include poor sanitization, severe malnutrition, and lack of breast feeding for infants, HIV infection, lack of immunization, chronic illness, family history of LRTI and exposure to tobacco smoke/air pollutants. The third generation cephalosporins are used in management and treatment of gram-negative and gram-positive organism. Common bacteria implicated in these infections include S. pneumoniae, H. influenzae, Chlamydia pneumoniae, and Staphylococcus aureus. Third generation cephalosporins also target respiratory ailments like acute bronchitis, pneumonia, acute exacerbation of chronic lung diseases (such as COPD or bronchiectasis). Cefotaxime and ceftriaxone have been widely recommended in guidelines to be used for many infections and diseases, but, some serious adverse effects have been seen in past few years with ceftriaxone like cholelithiasis, encephalopathy, memory impairment, tonic- clonic seizures, neurotoxicity and auto-immune haemolytic anaemia. This fact compels us to revisit the clinically safer and efficacious drug Cefotaxime which have been used since decades but have not developed any resistance till date. Cefotaxime has been found to be well tolerated and not associated with hypo-prothrombinemia/coagulopathies, disulfiram-like reactions, as with other cephalosporins. It can readily cross the blood-brain barrier when administered intravenously and may treat gram-negative infections resistant to previous generations of cephalosporins. Cefotaxime, demonstrates good efficacy and safety in the management of LRTIs including CAP, hospital acquired/nosocomial acquired pneumonia, acute exacerbation of pneumonia and acute bronchitis caused by both gram positive as well as gram negative bacteria. Keywords: LRTI, Cefotaxime, cephalosporins, CAP, pneumonia, respiratory tract

Disulfiram-like reaction with cefixime

Disulfiram-like reaction with cefixime

Comparison of Quantitative Values of Headspace Gas Chromatography--Mass Spectrometry and a Formate Quantification Kit in Blood Formate Quantification.

Methanol poisoning is caused by the toxicity of formate, a by-product of methanol metabolism. Measurement of blood formate concentrations is required for emergency treatment and investigation of the cause of death. In this study, we measured concentrations of formate in the plasma of a patient with methanol poisoning using headspace gas chromatography--mass spectrometry (HS-GC--MS) and a formate assay kit. Results showed a discrepancy as the quantitative values of the kit were higher than those of HS-GC--MS. Metabolic profiling of low-molecular-weight organic compounds in patient plasma samples showed that the concentrations of lactate were correlated with the values obtained using the kit. We observed a progression when lactate and lactate dehydrogenase were added to the kit reaction simultaneously, even in the absence of formate. Moreover, disulfiram, an aldehyde dehydrogenase inhibitor, suppressed the values of patient plasma samples in the formate assay kit, implying that formate production from remaining methanol in patient plasma samples via formaldehyde occurred during the kit reaction. The reactions of the kit with lactate and methanol were undesirable for accurate measurement of formate concentration in the sample. However, considering that elevated concentrations of lactate and remaining methanol both cause acidosis and are dangerous to the body, cross-reactions with lactate and methanol in the formate assay kit may be acceptable for rapid diagnosis in facilities where HS-GC--MS and other physical and chemical equipment are unavailable.

Targeting aldehyde dehydrogenase for prostate cancer therapies.

Prostate cancer (PCa) is the most common cancer in men in the United States. About 10 – 20% of PCa progress to castration-resistant PCa (CRPC), which is accompanied by metastasis and therapeutic resistance. Aldehyde dehydrogenase (ALDH) is famous as a marker of cancer stem-like cells in different cancer types, including PCa. Generally, ALDHs catalyze aldehyde oxidation into less toxic carboxylic acids and give cancers a survival advantage by reducing oxidative stress caused by aldehyde accumulation. In PCa, the expression of ALDHs is associated with a higher tumor stage and more lymph node metastasis. Functionally, increased ALDH activity makes PCa cells gain more capabilities in self-renewal and metastasis and reduces the sensitivity to castration and radiotherapy. Therefore, it is promising to target ALDH or ALDHhigh cells to eradicate PCa. However, challenges remain in moving the ALDH inhibitors to PCa therapy, potentially due to the toxicity of pan-ALDH inhibitors, the redundancy of ALDH isoforms, and the lack of explicit understanding of the metabolic signaling transduction details. For targeting PCa stem-like cells (PCSCs), different regulators have been revealed in ALDHhigh cells to control cell proliferation and tumorigenicity. ALDH rewires essential signaling transduction in PCa cells. It has been shown that ALDHs produce retinoic acid (RA), bind with androgen, and modulate diverse signaling. This review summarizes and discusses the pathways directly modulated by ALDHs, the crucial regulators that control the activities of ALDHhigh PCSCs, and the recent progress of ALDH targeted therapies in PCa. These efforts will provide insight into improving ALDH-targeted treatment.

An anti-alcoholism drug, disulfiram and copper complex improves radio-resistance of tumor-initiating cells in esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is a malignant cancer with a poor prognosis. Chemoradiotherapy is one of the most important strategies for patients with locally advanced unresectable ESCC; however, its therapeutic effect is unsatisfactory. Tumor-initiating cells (TICs) have been reported to be resistant to conventional chemotherapy and radiotherapy so far. Therefore, we aimed to develop a treatment strategy targeting TICs in ESCC to improve radiosensitivity. First, we validated aldehyde dehydrogenase 1 (ALDH1) as a TIC marker and investigated its ability to mediate resistance in human ESCC cell lines using flow cytometry, Western blotting, and functional analyses. Then, we focused on disulfiram (DSF), an aldehyde dehydrogenase inhibitor, used to treat alcohol use disorder. We investigated the effect of DSF and copper (II) D-gluconate (Cu) on the radiosensitivity of ESCC in xenograft mouse models. ALDH1-positive cells showed an upregulation of SOX2 and Nanog, exhibiting much stronger tumor-initiating properties than ALDH1-negative cells. Furthermore, inhibition of ALDH1 attenuated the tumor-initiating properties of ESCC cell lines. Our results also showed that ALDH1-positive cells were resistant to chemotherapy and radiotherapy, and the inhibition of ALDH1 led to the mitigation of therapeutic resistance. Our in vitro and in vivo studies revealed that the DSF/Cu complex could radiosensitize ALDH1-positive ESCC cells and downregulate the phosphoinositide 3-kinase/Akt pathway. ALDH1 inhibition by the DSF/Cu complex enhances the radiosensitivity of TICs in ESCC. The drug repositioning approach using disulfiram is a potential treatment option to overcome radioresistance in patients with locally advanced ESCC.

Anti-metastatic breast cancer potential of novel nanocomplexes of diethyldithiocarbamate and green chemically synthesized iron oxide nanoparticles

Mortality rate of metastatic breast cancer is linked to cancer stem cells (CSCs)’ aggressive features (chemoresistance to apoptosis and redox imbalance). Therefore, unique dual therapeutic strategy compacts CSCs with inducing oxidative stress-mediated nonapoptosis (ferroptosis), confers effective malignant tumor eradication. Diethyldithiocarbamate (DDC) is a potent inhibitor of CSC aldehyde dehydrogenase and lowers glutathione (GSH) which aggravate iron-dependent ferroptosis. Herein, nanoformulations of DDC with green chemically synthesized ferrous oxide nanoparticles (FeO NPs) and ferric oxide (Fe2O3 NPs) were prepared. Due to nanoparticle characters and synergistic effect between iron oxide NPs and DDC, nanocomplexes (DFeO NPs and DFe2O3 NPs, respectively) exhibited the strongest anti-metastatic cancer potency in vitro. Because of corresponding iron oxide nature, DFeO NPs demonstrated better therapeutic efficacy than DFe4O3 NPs, in mammary tumor liver metastasis-bearing mice, in terms of tumor size, histological analysis, immunostaining % of ki-67+ and caspase 3+, and gene expression of p53 and BCl2. The potent anti-tumor effect of DFeO nanocomplex is attributed to the maximum elevation of reactive oxygen species and lipid peroxidation (ferroptosis hall marker) with severe depletion of GSH and Nrf2 selectively in both tumor tissues, causing CSC eradication with halting metastatic activity. The latters were confirmed by lowering CD44+ % and gene expression of HIF-α, β-catenin, Notch, ABCG2-mediated chemoresistance, and MMP9 with diminishing liver tumor marker. Moreover, this nanocomplex did not cause any abnormal alterations in histological and biochemical parameters, compared to healthy group. Therefore, the selective apoptotic and ferroptotic with anti-CSC effects of DFeO NPs open new safe avenue for metastatic tumor therapy.

35361 Disulfiram-like reactions to topical tacrolimus: A case series

A 20-year-old Caucasian man presented to our clinic with pink papules coalescing into thin scaly plaques on the bilateral upper and lower eyelids, temples, and upper and lower cutaneous lips. He was diagnosed with periorificial dermatitis and prescribed topical tacrolimus 0.1% ointment. A 22-year-old Caucasian woman presented to our clinic with scattered monomorphic pink papules on the bilateral alar creases and lower cutaneous lip. She was diagnosed with periorificial dermatitis and prescribed tacrolimus 0.1% ointment.

Disulfiram and dithiocarbamate analogues demonstrate promising antischistosomal effects

Schistosomiasis is a neglected tropical disease with more than 200 million new infections per year. It is caused by parasites of the genus Schistosoma and can lead to death if left untreated. Currently, only two drugs are available to combat schistosomiasis: praziquantel and, to a limited extent, oxamniquine. However, the intensive use of these two drugs leads to an increased probability of the emergence of resistance. Thus, the search for new active substances and their targeted development are mandatory. In this study the substance class of “dithiocarbamates” and their potential as antischistosomal agents is highlighted. These compounds are derived from the basic structure of the human aldehyde dehydrogenase inhibitor disulfiram (tetraethylthiuram disulfide, DSF) and its metabolites. Our compounds revealed promising activity (in vitro) against adults of Schistosoma mansoni, such as the reduction of egg production, pairing stability, vitality, and motility. Moreover, tegument damage as well as gut dilatations or even the death of the parasite were observed. We performed detailed structure-activity relationship studies on both sides of the dithiocarbamate core leading to a library of approximately 300 derivatives (116 derivatives shown here). Starting with 100 μm we improved antischistosomal activity down to 25 μm by substitution of the single bonded sulfur atom for example with different benzyl moieties and integration of the two residues on the nitrogen atom into a cyclic structure like piperazine. Its derivatization at the 4-nitrogen with a sulfonyl group or an acyl group led to the most active derivatives of this study which were active at 10 μm. In light of this SAR study, we identified 17 derivatives that significantly reduced motility and induced several other phenotypes at 25 μm, and importantly five of them have antischistosomal activity also at 10 μm. These derivatives were found to be non-cytotoxic in two human cell lines at 100 μm. Therefore, dithiocarbamates seem to be interesting new candidates for further antischistosomal drug development.

Analysis of a Case of Disulfiram-like Reaction Caused by Cefoperazone Sulbactam Combined with Compound Licorice Oral Solution

Analysis of a Case of Disulfiram-like Reaction Caused by Cefoperazone Sulbactam Combined with Compound Licorice Oral Solution

Isothiocyanates (ITCs) 1-(Isothiocyanatomethyl)-4-phenylbenzene and 1-Isothiocyanato-3,5-bis(trifluoromethyl)benzene-Aldehyde Dehydrogenase (ALDH) Inhibitors, Decreases Cisplatin Tolerance and Migratory Ability of NSCLC.

One of the main treatment modalities for non-small-cell lung cancer (NSCLC) is cisplatin-based chemotherapy. However, the acquisition of cisplatin resistance remains a major problem. Existing chemotherapy regimens are often ineffective against cancer cells expressing aldehyde dehydrogenase (ALDH). As such, there is an urgent need for therapies targeting ALDH-positive cancer cells. The present study compares the anticancer properties of 36 structurally diverse isothiocyanates (ITCs) against NSCLC cells with the ALDH inhibitor disulfiram (DSF). Their potential affinity to ALDH isoforms and ABC proteins was assessed using AutoDockTools, allowing for selection of three compounds presenting the strongest affinity to all tested proteins. The selected ITCs had no impact on NSCLC cell viability (at tested concentrations), but significantly decreased the cisplatin tolerance of cisplatin-resistant variant of A549 (A549CisR) and advanced (stage 4) NSCLC cell line H1581. Furthermore, long-term supplementation with ITC 1-(isothiocyanatomethyl)-4-phenylbenzene reverses the EMT phenotype and migratory potential of A549CisR to the level presented by parental A549 cells, increasing E-Cadherin expression, followed by decreased expression of ABCC1 and ALDH3A1. Our data indicates that the ALDH inhibitors DSF and ITCs are potential adjuvants of cisplatin chemotherapy.

Synthesis, X-ray diffraction and anti-proliferative biological activity of hispolon derivatives and their (η6-p-cymene)(Hispolonato)Ruthenium[II] chloride complexes

Hispolon is a natural product extracted from Phellinus igniarius and Phellinus linteus fungi that has previously shown antitumor activity. In this study we present the synthesis, chemical characterization and in vitro anti-proliferative activity of three [(η6-p-cymene)Ru(L)Cl] neutral complexes, where L = hispolon derivatives. The single crystal X-ray structures of the three Ru complexes all have the expected piano stool geometry with the p-cymene ligand at the apex of the piano stool and occupying three of the sites in a distorted-octahedral arrangement. Completing the octahedral coordination sphere are two β-diketone oxygen atoms of the deprotonated hispolon derivatives which are coordinated in a bidentate fashionand a chlorine atom. The cytotoxicity of the three hispolon derivatives along with their corresponding complexes was studied for A549 lung, HCT116 colon and U87 glioblastoma cell lines. In the glioblastoma cell line, increase of biological activity (lower IC50) is seen for all three hispolons after arene-ruthenium complexation: 5.1 times higher for 2,3,4-trimethoxy-hispolon (Hisp8), and 1.5 times for both 3-methoxy,4-hydroxy-hispolon (Hisp1) and 3,4-dimethoxy-hispolon (Hisp4). This effect was less pronounced in the colon HCT116 cell line with complexation having 1.2–1.4 times higher biological activity. For the lung cell line A549, there was no such effect and complex formation slightly decreased the biological activity. Regardless, in the glioblastoma cell line, the presence of Hisp8, the most liposoluble agent, either as the pure compound or as ligand in the η6-p-cymene-Ru complex, proved effective as an antitumor agent. More specifically, the [(η6-p-cymene)Ru(Hisp8)Cl] complex showed a decrease in IC50 value for all 3 cell lines, when compared to Hisp8. We also performed molecular mechanics, DFT and docking calculations to determine the inhibitory ability of hispolon analogs towards aldehyde dehydrogenase, which targets glioblastoma stem cells. All three [(η6-p-cymene)Ru(Hisp)Cl] coordination complexes of hispolon derivatives are more effective than the related neutral hispolons in the U87 MG human glioblastoma cell line. Our computational studies clearly indicate an important role for aldehyde dehydrogenase Arg139 amino acid. In addition, computational results indicate hispolonato anions are much better inhibitors of aldehyde dehydrogenase and improve the anti-glioblastoma biological activity, consistent with IC50 data.

Disulfiram, an aldehyde dehydrogenase inhibitor, works as a potent drug against sepsis and cancer via NETosis, pyroptosis, apoptosis, ferroptosis, and cuproptosis

Regulated cell death (RCD) is essential for maintaining cell homeostasis and preventing diseases. Besides classical apoptosis, several novel nonapoptotic forms of RCD including NETosis, pyroptosis, ferroptosis, and cuproptosis have been reported and are increasingly being implicated in various cancers and inflammation. Disulfiram (DSF), an aldehyde dehydrogenase inhibitor, has been used clinically for decades as an anti-alcoholic drug. New studies have shown that DSF possesses potent anti-inflammatory and anti-cancer effects by regulating these new types of RCD. Here, we summarize the mechanisms and discuss the potential application of DSF in the treatment of cancers and inflammatory diseases.

Transcription factor p8 regulates autophagy in response to disulfiram via PI3K/mTOR/p70S6K signaling pathway in pancreatic cancer cells.

Disulfiram (DSF), which is an inhibitor of aldehyde dehydrogenase (ALDH) and approved by the FDA for the treatment of alcoholism previously, has been repurposed for use as a cancer treatment because of its potent effect in preclinical studies. In this study, we found that disulfiram forms potent complexes with copper (DSF/Cu) inhibited cell proliferation, induced apoptosis in human pancreatic cancer cells, which was detected by flow cytometry and western blotting. Meanwhile, autophagy and autophagic flux also clearly observed by transmission electron microscopy, confocal microscopy and flow cytometry. Our results also showed that DSF/Cu induced transcription factor p8 upregulation and PI3K/mTOR signaling pathway activation detected by real-time PCR and western blotting. Additionally, suppression of p8 inactivated the mTOR signaling pathway and autophagic flux maintained. Furthermore, mechanism study indicated that autophagy induced by DSF/Cu was regulated by p8 and wasrelated to PI3K/mTOR/p70S6K signaling pathway in pancreatic cancer cells. Our findings provide insights into the role of p8 in regulatingautophagy induced by DSF/Cu effectsin pancreatic cancer cells.

Abstract 1820: N,N-diethylaminobenzaldehyde-based small molecules to probe aldehyde dehydrogenase as target in prostate cancer

Abstract The human aldehyde dehydrogenases (ALDHs) play a major role in the metabolism of endogenous compounds and xenobiotics. Deregulation of ALDHs have implications in a number of cancers and their elevated expression in cancer stem cells (CSCs) have been used as (1) markers for the identification and isolation of these rare cell types and (2) as potential targets for therapeutic intervention. The elevated ALDH expression in tumors is also known to lead to chemotherapy-resistance including taxanes resistance. Although the exact role of ALDHs is not fully understood, emerging information indicates that several isoforms including ALDH1A1, 1A3, 3A1 and 7A1 play a key role in prostate cancer. To unravel ALDH isoform significance, more selective chemical tool compounds are required to probe their role in tumor growth, drug-resistance and CSC protection. To further elucidate the role of ALDHs in prostate cancer, we here report on the perturbation of ALDH expression and function using new chemical probes. N,N-diethylaminobenzaldehyde (DEAB) is a well-known pan ALDH inhibitor, widely used to interrogate ALDH activity. However, its nonselective nature and reported ability to act as a substrate complicates its use for biological readouts, which we wanted to explore further. In this study, a new library of compounds were synthesized and evaluated in cell free and cell-based assays; particular focus was on understanding its interaction with the three key ALDH isoforms ALDH1A1, ALDH1A3 and ALDH3A1. Kinetic inhibitory studies using the human recombinant ALDH isoforms were performed for the whole library of DEAB analogues against ALDH1A1, 1A3 and 3A1. Among all results, compound 14 yielded selective results against ALDH1A3 (Ki of 0.46µM), while compound 18 showed promising results against ALDH3A1 (Ki of 0.30µM). Significantly, sixteen analogues displayed increased cytotoxicity (IC50 = 10-200 µM) compared with DEAB (> 200 µM) against three different prostate cancer cell lines (PC-3, LNCaP, DU145). In addition, 3 of the DEAB-derivatives ALDH-affinic probe compounds (9, 14 and 18) were tested against 5 patient samples of primary prostate epithelial cultures at two doses (50 and 200 µM) in order to investigate their effect on cell viability. All four compounds showed reduction in cell viability at the highest concentration, while 14 and 18 showed a synergistic effect in combination treatment with docetaxel. Similar observations were also evident in the PC-3 prostate cancer cell line. Our investigation demonstrates the importance of ALDHs in prostate cancer while new compounds warrant further studies to understand their potential in inhibiting prostate CSCs. Citation Format: Elisabet Batlle Rocafort, Ali I. Ibrahim, Maria Sadiq, Sneha Smarakan, Vibhu Jha, Tiziano Tuccinardi, Fiona Frame, Norman Maitland, Rafael Jiménez Aguilar, Raquel Pequerul Pavón, Xavier Parés Casampera, Goreti Ribeiro Morais, Jaume Farrés Vicen, Klaus Pors. N,N-diethylaminobenzaldehyde-based small molecules to probe aldehyde dehydrogenase as target in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1820.

Phase II study of disulfiram (D) and cisplatin (P) in refractory germ cell tumors (GCTs).

e17013 Background: Multiple relapsed/refractory GCTs patients have extremely poor prognosis, therefore, new treatment strategies are warranted. Previously, we showed, that cisplatin resistant testicular GCTs overexpress aldehyde-dehydrogenase (ALDH) isoforms and inhibition of ALDH activity by disulfiram is associated with reconstitution of cisplatin sensitivity in vitro as well as in animal model. This study aimed to determine the efficacy and toxicity of ALDH inhibitor disulfiram in combination with cisplatin in patients with multiple relapsed/refractory germ cell cancer. Methods: Twelve patients with multiple relapsed/refractory GCTs were enrolled in the phase II study from May 2019 to September 2021. All patients were pretreated with at least 2 cisplatin-based therapies (median 4, range 2 – 7); 6 tumors (50.0%) were absolutely refractory to cisplatin and 9 patients (75.0%) had visceral non-pulmonary metastases. Disulfiram was administered at a dose of 400 mg daily until progression or unacceptable toxicity, cisplatin was administered at dose 50 mg/m2 day 1 and 2, every 3 weeks. Twelve evaluable patients had to be enrolled into the first cohort, and if 0 of 12 patients had treatment response, the study was to be terminated. The results of the first stage of the trial are presented in the this report. Results: Median age was 36 years (range: 29 – 48 years). Median number of treatment cycles was 2 (range 1 – 6). During a median follow-up period of 3.1 months (range: 1.3 – 13.9), all (100%) patients experienced disease progression and died. None of patients achieved objective response to treatment, therefore the study was terminated in first stage. Median progression-free survival (PFS) was 1.4 months, 95% CI (0.7 – 1.5 months), and median overall survival (OS) was 2.9 months 95% CI (1.5 – 4.7 months). Disease stabilization for at least 6 months was observed in 2 (16.7%) patients. Treatment was well tolerated, however, 5 (41.7%) of patients experienced grade 3/4 fatigue, 4 (33.3%) thrombocytopenia, 3 (25.0%) anemia, while 2 (16.7%) experienced neutropenia, nausea and infection. Conclusions: This study failed to achieve its primary end point and our data suggest limited efficacy of disulfiram in restoring sensitivity to cisplatin in multiple relapsed/refractory germ cell tumors. Clinical trial information: NCT03950830.