Cancer Therapeutic Targeting of Hypoxia Induced Carbonic Anhydrase IX: From Bench to Bedside

New 7-hydroxycoumarin acetamide derivatives as human carbonic anhydrase IX and XII inhibitors: Design, synthesis, biological evaluation and molecular docking studies

Carbonic anhydrases (CAs) are crucial in regulating various physiological processes in the body. The overexpression of isoforms human carbonic anhydrases (hCA) IX and hCA XII is linked to tumour progression. The selective inhibition of CA IX and CA XII isoforms can result in the development of better cancer treatment strategies. The tail approach based on coumarin derivatives was known for selective inhibition of isoforms IX and XII. This study explores the potential of coumarin derivatives (7a-k, 8a-s and 9a-g) as selective hCA IX and hCA XII inhibitors. The synthesised derivatives exhibited potent and selective inhibition towards hCA IX and XII, with Ki values in the range of 0.58‒3.33 µM and 0.48‒2.59 µM, respectively. The oxime ether derivative 7d was found to be the most potent one against hCA IX, with a Ki value of 0.58 µM, and phenyl hydrazine derivative 8a, with a Ki value of 0.48 µM against hCA XII, was the most potent one among the synthesised molecules. The potent isoform-specific carbonic anhydrase IX and XII inhibition suggests that 7d and 8a can be taken further towards the development of potent anticancer agents.

The Antiepileptic Drug Levetiracetam Inhibits Carbonic Anhydrase: In Vitro and In Silico Studies on Catalytically Active Human Isoforms

Several antiepileptic drugs (AEDs) have been found to inhibit human carbonic anhydrases (hCAs), paving the way for repurposing AEDs for the treatment of various diseases, including cancer. Here, the hCAs inhibitory effects of levetiracetam, a highly prescribed AED that does not bear a common zinc-binding group, were investigated in vitro and in silico. Levetiracetam inhibited all tested hCAs, although with a specific profile compared to the reference acetazolamide, with remarkable efficacy against tumor-associated hCA IX and XII. Molecular docking and dynamics (MD) simulations emphasized H-bonding to the Zn(II)-coordinated water as a major anchor point for hCAs, as well as a persistent interaction within the catalytic site of hCA isoforms IX and XII compared to II, which correlates with experimental data. Our results may explain why levetiracetam is also clinically effective as an antitumor agent in patients developing epilepsy as a consequence of brain tumors.

Synthesis and investigation of selective human carbonic anhydrase IX, XII inhibitors using coumarins bearing a sulfonamide or biotin moiety

The role of carbonic anhydrases isoforms (CAs) IX and XII in the pathogenesis and progression of many types of solid tumors is well known. In this context, selective CA inhibitors (CAIs) towards the mentioned isoforms is a validated strategy for the development of agents to target cancer. For this purpose, novel coumarin derivatives based on the hybridization with arylsulfonamide or biotin scaffolds were synthesized and tested as inhibitors of four different human carbonic anhydrases isoforms: hCA I, II, IX and XII. Coumarin-sulfonamide derived 27, with a thiourea moiety and triazole as linker, showed the highest inhibition activity against hCA XII with an inhibition constant (KI) of 7.5 nM and afforded a very good selectivity over hCA I. Compound 32 was the most potent inhibitor against hCA IX (KI = 6.3 nM), 4-fold stronger than the drug acetazolamide AAZ (KI = 25 nM), used herein as a reference compound, and showed remarkable selectivity over hCA I and II. The coumarin-biotin derivatives 37-39 showed outstanding selectivity towards on-target enzymes (hCA IX and XII) and appear as plausible leads for designing of CAIs.

Novel benzenesulfonamide-aroylhydrazone conjugates as carbonic anhydrase inhibitors that induce MAPK/ERK-mediated cell cycle arrest and mitochondrial-associated apoptosis in MCF-7 breast cancer cells

A series of novel 4-alkylthio-2-chloro-5-[(2-arylmethylidene)hydrazinecarbonyl]benzenesulfonamide derivatives 3-22 were synthesized and evaluated for their inhibitory activity against human carbonic anhydrase isozymes hCA I, hCA II, hCA IX, and hCA XII. These compounds showed varying degrees of activity against the studied isoenzymes. However, the importance of substituent choice in designing potent carbonic anhydrase inhibitors is highlighted by the strong inhibition profiles of compounds 3 and 10 against hCA IX and the low average KI values for compounds 9 and 10 (134 nM and 77 nM, respectively). All the synthesized compounds were evaluated for their antiproliferative activity toward HeLa, HCT-116, and MCF-7 cell lines. Compounds 9 and 19 exhibited significant activity, particularly against the MCF-7 cell line (IC50 values of 4 μM and 6 μM, respectively). Notably, compound 9 demonstrated a high selectivity index (SI = 8.2) for MCF-7 cells. The antiproliferative effects of compounds 9 and 19 were linked to the induction of cell cycle arrest and apoptosis via the mitochondrial pathway and involved the activation of the MAPK/ERK signaling pathway. Inhibition of MAPK/ERK activity reduced the compounds' ability to induce cell cycle arrest and apoptosis, indicating the critical role of this pathway. These findings suggest that compounds 9 and 19 are promising candidates for further development as specific and potent anticancer agents targeting the MAPK/ERK pathway.

Exploring the Polypharmacological Potential of PCI-27483: A Selective Inhibitor of Carbonic Anhydrases IX and XII

PCI-27483, originally developed as a potent and selective inhibitor of the serine protease Factor VIIa (FVIIa) in complex with tissue factor (TF), has demonstrated significant promise in cancer therapy. In addition to its primary mechanism of action, the presence of a sulfonamide moiety in the PCI-27483 structure suggests further activities through the inhibition of carbonic anhydrases (CAs), particularly the tumor-associated human (h)CA isoforms hCA IX and XII. This study investigates the inhibitory activity of PCI-27483 against the complete panel of active hCAs, highlighting its polypharmacological potential in cancer treatment. X-ray crystallography and molecular docking studies elucidated the structural features underlying its selective inhibitory activity toward hCA IX and XII, offering insights into its dual-targeting pathway.

Exploration of 1,3,5-trisubstituted pyrazoline derivatives as human carbonic anhydrase inhibitors: Synthesis, biological evaluation and in silico studies

The human carbonic anhydrase (hCA) IX and XII isoforms are overexpressed in hypoxic conditions, contributing to cancer. Lack of isoform selectivity has been one of the main challenges associated with the existing drugs targeting hCAs. Hence, the development of alternative approaches, such as tail approach to develop more selective hCA IX and XII inhibitors is need of the hour. In the present work, we designed and synthesized 24 new 1,3.5-trisubstituted-pyrazoline derivatives with diverse substitutions. The synthesized analogs were evaluated for their hCA inhibitory activities against hCA I, II, IX, and XII isoforms. Among the tested compounds, derivative 8 displayed good inhibitory activity against hCA IX (Ki = 331 nM) and XII (Ki = 96.7 nM). In addition, 9a-g also exhibited some inhibitory activities against hCA IX and XII, with Kis ranging from 574-799 nM and 137-369 nM, respectively. Molecular modelling studies of compound 8 displayed metal coordination with zinc ion and hydrophobic, hydrophilic interactions with adjacent amino acid residues, and maintained stable interactions throughout 100 ns. In addition, ADMET studies demonstrated that compound 8 obeyed the Lipinski's rule of five and was found to be druggable and non-toxic. Hence, compound 8 was identified as potential lead for further development.

IL-22 regulates MASTL expression in intestinal epithelial cells

Microtubule-associated serine-threonine kinase-like (MASTL) has recently been identified as an oncogenic kinase given its overexpression in numerous cancers. Our group has shown that MASTL expression is upregulated in mouse models of sporadic colorectal cancer and colitis-associated cancer (CAC). CAC is one of the most severe complications of chronic inflammatory bowel disease (IBD), but a limited understanding of the mechanisms governing the switch from normal healing to neoplasia in IBD underscores the need for increased research in this area. However, MASTL levels in patients with IBD and its molecular regulation in IBD and CAC have not been studied. This study reveals that MASTL is upregulated by the cytokine interleukin (IL)-22, which promotes proliferation and has important functions in colitis recovery; however, IL-22 can also promote tumorigenesis when chronically elevated. Upon reviewing the publicly available data, we found significantly elevated MASTL and IL-22 levels in the biopsies from patients with late-stage ulcerative colitis compared with controls, and that MASTL upregulation was associated with high IL-22 expression. Our subsequent in vitro studies found that IL-22 increases MASTL expression in intestinal epithelial cell lines, which facilitates IL-22-mediated cell proliferation and downstream survival signaling. Inhibition of AKT activation abrogated IL-22-induced MASTL upregulation. We further found an increased association of carbonic anhydrase IX (CAIX) with MASTL in IL-22-treated cells, which stabilized MASTL expression. Inhibition of CAIX prevented IL-22-induced MASTL expression and cell survival. Overall, we show that IL-22/AKT signaling increases MASTL expression to promote cell survival and proliferation. Furthermore, CAIX associates with and stabilizes MASTL in response to IL-22 stimulation.NEW & NOTEWORTHY MASTL is upregulated in colorectal cancer; however, its role in colitis and colitis-associated cancer is poorly understood. This study is the first to draw a link between MASTL and IL-22, a proinflammatory/intestinal epithelial recovery-promoting cytokine that is also implicated in colon tumorigenesis. We propose that IL-22 increases MASTL protein stability by promoting its association with CAIX potentially via AKT signaling to promote cell survival and proliferation.

New Horizons of Synthetic Lethality in Cancer: Current Development and Future Perspectives

In recent years, synthetic lethality has been recognized as a solid paradigm for anticancer therapies. The discovery of a growing number of synthetic lethal targets has led to a significant expansion in the use of synthetic lethality, far beyond poly(ADP-ribose) polymerase inhibitors used to treat BRCA1/2-defective tumors. In particular, molecular targets within DNA damage response have provided a source of inhibitors that have rapidly reached clinical trials. This Perspective focuses on the most recent progress in synthetic lethal targets and their inhibitors, within and beyond the DNA damage response, describing their design and associated therapeutic strategies. We will conclude by discussing the current challenges and new opportunities for this promising field of research, to stimulate discussion in the medicinal chemistry community, allowing the investigation of synthetic lethality to reach its full potential.

Design and synthesis of chromene-1,2,3-triazole benzene sulfonamide hybrids as potent carbonic anhydrase-IX inhibitors against prostate cancer

Considering the promising effects of molecular hybridization on drug discovery in recent years and the ongoing endeavors to develop bioactive scaffolds tethering the 1,2,3-triazole core, the present study sought to investigate whether the 1,2,3-triazole-linked chromene and benzene sulfonamide nucleus could exhibit activity against the human breast cancer cell line MCF-7 and prostate cancer cell line PC-3. To this end, three focused bioactive series of mono- and -bis-1,2,3-triazoles were effectively synthesized via copper-assisted cycloaddition of mono- and/or di-alkyne chromenone derivatives 2a and b and 9 with several sulfa drug azides 4a-d and 6. The resulting molecular derivatives were tested for cytotoxicity against prostate and breast cancer cells. Among the derivatives, 10a, 10c, and 10e exhibited potent cytotoxicity against PC-3 cells with IC50 values of 2.08, 7.57, and 5.52 μM compared to doxorubicin (IC50 = 2.31 μM) with potent inhibition of CA IX with IC50 values of 0.113, 0.134, and 0.214 μM. The most active compound, 10a, was tested for apoptosis-induction; it induced apoptosis by 31.9-fold cell cycle arrest at the G1-phase. Further, the molecular modeling approach highlighted the relevant binding affinity for the top-active compound 10a against CA IX as one of the most prominent PC-3 prostate cancer-associated biotargets.

Isocoumarins incorporating chalcone moieties act as isoform selective tumor-associated carbonic anhydrase inhibitors

Aim: A series of isocoumarin-chalcone hybrids were prepared and assays for the inhibition of four isoforms of human carbonic anhydrase (hCA; EC 4.2.1.1), hCA I, II, IX and XII. Materials & methods: Isocoumarin-chalcone hybrids were synthesized by condensing acetyl-isocoumarin with aromatic aldehydes. They did not significantly inhibit off-target cytosolic isoforms hCA I and II (KI >100 μM) but acted as low micromolar or submicromolar inhibitors for the tumor-associated isoforms hCA IX and XII. Results & conclusion: Our work provides insights into a new and scarcely investigated chemotype which provides interesting tumor-associated CA inhibitors, considering that some such derivatives like sulfonamide SLC-0111 are in advanced clinical trials for the management of metastatic advanced solid tumors.

Carbonic anhydrase IX: An atypical target for innovative therapies in cancer

Carbonic anhydrases (CAs), are metallo-enzymes implicated in several pathophysiological processes where tissue pH regulation is required. CA IX is a tumor-associated CA isoform induced by hypoxia and involved in the adaptation of tumor cells to acidosis. Indeed, several tumor-driving pathways can induce CA IX expression, and this in turn has been associated to cancer cells invasion and metastatic features as well as to induction of stem-like features, drug resistance and recurrence. After its functional and structural characterization CA IX targeting approaches have been developed to inhibit its activity in neoplastic tissues, and to date this field has seen an incredible acceleration in terms of therapeutic options and biological readouts. Small molecules inhibitors, hybrid/dual targeting drugs, targeting antibodies and adoptive (CAR-T based) cell therapy have been developed at preclinical level, whereas a sulfonamide CA IX inhibitor and an antibody entered Phase Ib/II clinical trials for the treatment and imaging of different solid tumors. Here recent advances on CA IX biology and pharmacology in cancer, and its therapeutic targeting will be discussed.

Thetumor microenvironment'sinpancreatic cancer:Effects onimmunotherapy successandnovel strategiestoovercomethehostile environment

Cancer is a significant global health issue that poses a considerable burden on both patients and healthcare systems. Many different types of cancers exist that often require unique treatment approaches and therapies. A hallmark of tumor progression is the creation of an immunosuppressive environment, which poses complex challenges for current treatments. Amongst the most explored characteristics is a hypoxic environment, high interstitial pressure, and immunosuppressive cells and cytokines. Traditional cancer treatments involve radiotherapy, chemotherapy, and surgical procedures. The advent of immunotherapies was regarded as a promising approach with hopes of greatly increasing patients' survival and outcome. Although some success is seen with various immunotherapies, the vast majority of monotherapies are unsuccessful. This review examines how various aspects of the tumor microenvironment (TME) present challenges that impede the success of immunotherapies. Subsequently, we review strategies to manipulate the TME to facilitate the success of immunotherapies.

Benzenesulfonamide decorated dihydropyrimidin(thi)ones: carbonic anhydrase profiling and antiproliferative activity

In the last decades, carbonic anhydrases (CAs) have become the top investigated innovative pharmacological targets and, in particular, isoforms IX and XII have been widely studied due to the evidence of their overexpression in hypoxic tumors. The frantic race to find new anticancer agents places the quick preparation of large libraries of putative bioactive compounds as the basis of a successful drug discovery and development programme. In this context, multi-component and, in general, one-step reactions are becoming very popular and, among them, Biginelli's reaction gave clean and easy-to-isolate products. Thus, we synthesized a series of Biginelli's products (10-17a-b) and similar derivatives (20-21) bearing the benzenesulfonamide moiety, which is known to inhibit CA enzymes. Through the stopped-flow technique, we were able to assess their ability to inhibit the targeted CAs IX and XII in the nanomolar range with promising selectivity over the physiologically relevant isoforms I and II. Crystallography studies and docking simulations helped us to gain insight into the interaction patterns established in the enzyme-inhibitor complex. From a chemical similarity-based screening of in-house libraries of compounds, a diphenylpyrimidine (23) emerged. The surprisingly potent inhibitory activity of 23 for CAs IX and XII along with its strong antiproliferative effect on two (triple-negative breast cancer MDA-MB-231 and glioblastoma U87MG) cell lines laid the foundation for further investigation, again confirming the key role of CAs in cancer.

Novel 2,4-Dichloro-5-sulfamoylbenzoic Acid Oxime Esters: First Studies as Potential Human Carbonic Anhydrase Inhibitors

In this study, a focused library of oxime ester derivatives of 2,4-dichloro-5-sulfamoylbenzoic acid (lasamide) containing Schiff bases was synthesized and tested in vitro for their ability to inhibit the cytosolic human carbonic anhydrases (hCAs) I and II, as well as the transmembrane and tumor-associated IX and XII isoforms. As a result, we obtained a first line of knowledge on lasamide derivatives potentially useful for development as CA inhibitors (CAIs). In particular, we focused our attention on the derivative 11, which was selective toward hCAs IX and XII over the cytosolic isoenzymes. An in silico study was conducted to assess the binding mode of 11 within hCAs IX and XII. Also, antiproliferative assays highlighted promising derivatives. The data obtained in this study are currently in use for the development of better-performing compounds on the tumor-associated isoforms.

Unraveling the Impact of Six Pentacyclic Triterpenes Regulating Metabolic Pathways on Lung Carcinoma Cells

Recently, there has been great interest in plant-derived compounds known as phytochemicals. The pentacyclic oleanane-, ursane-, and lupane-type triterpenes are phytochemicals that exert significant activity against diseases like cancer. Lung cancer is the leading cause of cancer-related death worldwide. Although chemotherapy is the treatment of choice for lung cancer, its effectiveness is hampered by the dose-limiting toxic effects and chemoresistance. Herein, we investigated six pentacyclic triterpenes, oleanolic acid, ursolic acid, asiatic acid, betulinic acid, betulin, and lupeol, on NSCLC A549 cells. These triterpenes have several structural variations that can influence the activation/inactivation of key cellular pathways. From our results, we determined that most of these triterpenes induced apoptosis, S-phase and G2/M-phase cycle arrest, the downregulation of ribonucleotide reductase (RR), reactive oxygen species, and caspase 3 activation. For chemoresistance markers, we found that most triterpenes downregulated the expression of MAPK/PI3K, STAT3, and PDL1. In contrast, UrA and AsA also induced DNA damage and autophagy. Then, we theoretically determined other possible molecular targets of these triterpenes using the online database ChEMBL. The results showed that even slight structural changes in these triterpenes can influence the cellular response. This study opens up promising perspectives for further research on the pharmaceutical role of phytochemical triterpenoids.

Effective Anticancer Potential of a New Sulfonamide as a Carbonic Anhydrase IX Inhibitor Against Aggressive Tumors

This study examines efficiency of a newly synthesized sulfonamide derivative 2-bromo-N-(4-sulfamoylphenyl)propanamide (MMH-1) on the inhibition of Carbonic Anhydrase IX (CA IX), which is overexpressed in many solid tumors including breast cancer. The inhibitory potential of MMH-1 compound against its four major isoforms, including cytosolic isoforms hCA I and II, as well as tumor-associated membrane-bound isoforms hCA IX and XII, was evaluated. To this context, the cytotoxic effect of MMH-1 on cancer and normal cells was tested and found to selectively affect MDA-MB-231 cells. MMH-1 reduced cell proliferation by holding cells in the G0/G1 phase (72 %) and slowed the cells' wound healing capacity. MMH-1 inhibited CA IX under both hypoxic and normoxic conditions and altered the morphology of triple negative breast cancer cells. In MDA-MB-231 cells, inhibition of CA IX was accompanied by a decrease in extracellular pH acidity (7.2), disruption of mitochondrial membrane integrity (80 %), an increase in reactive oxygen levels (25 %), and the triggering of apoptosis (40 %). In addition, the caspase cascade (CASP-3, -8, -9) was activated in MDA-MB-231 cells, triggering both the extrinsic and intrinsic apoptotic pathways. The expression of pro-apoptotic regulatory proteins (Bad, Bax, Bid, Bim, Cyt-c, Fas, FasL, TNF-a, TNF-R1, HTRA, SMAC, Casp-3, -8, P21, P27, and P53) was increased, while the expression of anti-apoptotic proteins, apoptosis inhibitor proteins (IAPs), and heat shock proteins (HSPs) (Bcl-2, Bcl-w, cIAP-2, HSP27, HSP60, HSP70, Survivin, Livin, and XIAP) was decreased. These results propose that the MMH-1 compound could triggers apoptosis in MDA-MB-231 cells via the pH/MMP/ROS pathway through the inhibition of CA IX. This compound is thought to have high potential and promising anticancer properties in the treatment of aggressive tumors.

Identification of a Gene Expression Signature to Predict the Risk of Early Recurrence and the Degree of Immune Cell Infiltration in Triple-negative Breast Cancer

BACKGROUND/AIM

Patients with triple-negative breast cancer (TNBC) have a high rate of recurrence within 3 years of diagnosis and a high rate of death within 5 years compared to other subtypes. The number of clinical trials investigating various new agents and combination therapies has recently increased; however, current strategies benefit only a minority of patients. This study aimed to identify specific genes that predict patients at high risk of recurrence and the immune status of the tumor microenvironment at an early stage, thereby providing insight into potential therapeutic targets to improve clinical outcomes in TNBC patients.

MATERIALS AND METHODS

We evaluated the prognostic significance of microarray mRNA expression of 20,603 genes in 233 TNBC patients from the METABRIC dataset and further validated the results using RNA-seq mRNA expression data in 143 TNBC patients from the GSE96058 dataset.

RESULTS

Eighteen differentially expressed genes (AKNA, ARHGAP30, CA9, CD3D, CD3G, CD6, CXCR6, CYSLTR1, DOCK10, ENO1, FLT3LG, IFNG, IL2RB, LPXN, PRKCB, PVRIG, RASSF5, and STAT4) identified in both datasets were found to be reliable biomarkers for predicting TNBC recurrence and progression. Notably, the genes whose low expression was associated with increased risk of recurrence and death were immune-related genes, with significant differences in levels of immune cell infiltration in the tumor microenvironment between high- and low- expression groups.

CONCLUSION

Genes reported herein may be effective biomarkers to identify TNBC patients who will and will not benefit from immunotherapy and may be particularly important genes for developing future treatment strategies, including immunotherapy.

A comparative study of diaryl urea molecules with and without sulfonamide group on Carbonic anhydrase IX and XII inhibition and its consequence on breast cancer cells

To investigate the intrinsic relation between carbonic anhydrase inhibition and anticancer activity, we have prepared four sets of diaryl urea molecules and tested for the inhibition of hCA-IX and XII on two breast cancer cell lines. Among 21 compounds, compound J2 (with -SO2NH2 group) and J16 (without -SO2NH2 group) showed the best activity under normoxic and hypoxic conditions. The IC50 values of J16 for MDA-MB-231 and MCF-7 cells, under normoxic condition were 6.3 and 3.7 µM respectively, which are 1.9/3.3 and 15.8 times better than U-4-Nitro and SLC-0111 respectively. Whereas, under the hypoxic condition the corresponding values were 12.4 and 1.1 µM (MDA-MB-231 and MCF-7 cells respectively), which are equal/8 times better than U-4-Nitro. Whereas, J2 showed better IC50 value than U-4-Nitro (6.3 µM) under normoxic condition for both MDA-MB-231 and MCF-7 cells (1.9/2.7 times). Compound J2 inhibits the activity of hCA-IX and XII in nanomolar concentration [Ki values 4.09 and 9.10 nM respectively with selectivity ratio of 1.8 and 0.8 with hCA-II]. The crystal structure and modelling studies demonstrates that the inhibition of CAs arises due to the blocking of the CO2 coordination site of zinc in its catalytic domain. However, J16 was found to be unable to inhibit the activity of hCAs (Ki > 89000 nM). qPCR and western blot analysis showed a significant reduction (1.5 to 20 fold) of the transcription and expression of HIF1A, CA9 and CA12 genes in presence of J2 and J16. Both J2 and J16 found to reduce accumulation of HIF-1α protein by inhibiting the chaperone activity of hHSP70 with IC50 values of 19.4 and 15.3 µM respectively. Perturbation of the hCA-IX and XII activity by binding at active site or by reduced expression or by both leads to the decrease of intracellular pH, which resulted in concomitant increase of reactive oxygen species by 2.6/2.0 (MCF-7) and 2.9/1.8 (MDA-MB-231) fold for J2/J16. Increased cyclin D1 expression in presence of J2 and J16 was presumed to be indirectly responsible for the apoptosis of the cancer cells. Expression of the other apoptosis markers Bcl-2, Bim, caspase 9 and caspase 3 substantiated the apoptosis mechanism. However, decreased transcription/expression of HIF1A/HIF-1α and hCA-IX/XII also implies the inhibition of the extracellular signal-regulated kinase pathway by J2 and J16.

Drug interactions of carbonic anhydrase inhibitors and activators

INTRODUCTION

Carbonic anhydrases (CAs, EC 4.2.1.1) have been established drug targets for decades, with their inhibitors and activators possessing relevant pharmacological activity and applications in various fields. At least 11 sulfonamides/sulfamates are clinically used as diuretics, antiglaucoma, antiepileptic, or antiobesity agents and one derivative, SLC-0111, is in clinical trials as antitumor/antimetastatic agent. The activators were less investigated with no clinically used agent.

AREAS COVERED

Drug interactions between CA inhibitors/activators and various other agents are reviewed in publications from the period March 2020 - January 2024.

EXPERT OPINION

Drug interactions involving these agents revealed several interesting findings. Acetazolamide plus loop diuretics is highy effective in acute decompensated heart failure, whereas ocular diseases such as X-linked retinoschisis and macular edema were treated by acetazolamide plus bevacizumab or topical NSAIDs. Potent anti-infective effects of acetazolamide and other CAIs, alone or in combination with other agents were demonstrated for the management of Neisseria gonorrhoea, vancomycin resistant enterococci, Acanthamoeba castellanii, Trichinella spiralis, and Cryptococcus neoformans infections. Topiramate, in combination with phentermine is incresingly used for the management of obesity, whereas zonisamide plus levodopa is highly effective for Parkinson's disease. Acetazolamide, methazolamide, ethoxzolamide, and SLC-0111 showed synergistic antitumor/antimetastatic action in combination with many other antitumor drugs.

Metabolic challengers selecting tumor-persistent cells

Resistance to anticancer therapy still represents one of the main obstacles to cancer treatment. Numerous components of the tumor microenvironment (TME) contribute significantly to the acquisition of drug resistance. Microenvironmental pressures arising during cancer evolution foster tumor heterogeneity (TH) and facilitate the emergence of drug-resistant clones. In particular, metabolic pressures arising in the TME may favor epigenetic adaptations supporting the acquisition of persistence features in tumor cells. Tumor-persistent cells (TPCs) are characterized by high phenotypic and metabolic plasticity, representing a noticeable advantage in chemo- and radio-resistance. Understanding the crosslink between the evolution of metabolic pressures in the TME, epigenetics, and TPC evolution is significant for developing novel therapeutic strategies specifically targeting TPC vulnerabilities to overcome drug resistance.

Decoding of the surfaceome and endocytome in primary glioblastoma cells identifies potential target antigens in the hypoxic tumor niche

Immunotherapies with antibody-drug-conjugates (ADC) and CAR-T cells, targeted at tumor surface antigens (surfaceome), currently revolutionize clinical oncology. However, target identification warrants a better understanding of the surfaceome and how it is modulated by the tumor microenvironment. Here, we decode the surfaceome and endocytome and its remodeling by hypoxic stress in glioblastoma (GBM), the most common and aggressive brain tumor in adults. We employed a comprehensive approach for global and dynamic profiling of the surfaceome and endocytosed (endocytome) proteins and their regulation by hypoxia in patient-derived GBM cultures. We found a heterogeneous surface-endocytome profile and a divergent response to hypoxia across GBM cultures. We provide a quantitative ranking of more than 600 surface resident and endocytosed proteins, and their regulation by hypoxia, serving as a resource to the cancer research community. As proof-of-concept, the established target antigen CD44 was identified as a commonly and abundantly expressed surface protein with high endocytic activity. Among hypoxia induced proteins, we reveal CXADR, CD47, CD81, BSG, and FXYD6 as potential targets of the stressed GBM niche. We could validate these findings by immunofluorescence analyses in patient tumors and by increased expression in the hypoxic core of GBM spheroids. Selected candidates were finally confronted by treatment studies, showing their high capacity for internalization and ADC delivery. Importantly, we highlight the limited correlation between transcriptomics and proteomics, emphasizing the critical role of membrane protein enrichment strategies and quantitative mass spectrometry. Our findings provide a comprehensive understanding of the surface-endocytome and its remodeling by hypoxia in GBM as a resource for exploration of targets for immunotherapeutic approaches in GBM.

1,3-Diaryl Triazenes Incorporating Disulfonamides Show Both Antiproliferative Activity and Effective Inhibition of Tumor-associated Carbonic Anhydrases IX and XII

AIM

The aim of this study was to synthesize a library of novel di-sulfa drugs containing 1,3- diaryltriazene derivatives TS (1-13) by conjugation of diazonium salts of primary sulfonamides with sulfa drugs to investigate the cytotoxic effect of these new compounds in different cancer types and to determine their inhibitory activity against tumor-associated carbonic anhydrases IX and XII.

MATERIALS AND METHODS

A carbonic anhydrase inhibitory activity of the obtained compounds was evaluated against four selected human carbonic anhydrase isoforms (hCA I, hCA II, hCA IX and hCA XII) by a stoppedflow CO2 hydrase assay. In addition, in vitro, cytotoxicity studies were applied by using A549 (lung cancer), BEAS-2B (normal lung), MCF-7 (breast cancer), MDA-MB-231 (breast cancer), CRL-4010 (normal breast epithelium), HT-29 (colon cancer), and HCT -116 (colon cancer) cell lines.

RESULTS

As a result of the inhibition data, the 4-aminobenzenesulfonamide derivatives were more active than their 3-aminobenzenesulfonamide counterparts. More specifically, compounds TS-1 and TS-2, both of which have primary sulfonamides on both sides of the triazene linker, showed the best inhibitory activity against hCA IX with Ki values of 19.5 and 13.7 nM and also against hCA XII with Ki values of 6.6 and 8.3 nM, respectively. In addition, in vitro cytotoxic activity on the human breast cancer cell line MCF-7 showed that some derivatives of di-sulfa triazenes, such as TS-5 and TS-13, were more active than SLC-0111.

CONCLUSION

With the aim of developing more potent and isoform-selective CA inhibitors, these novel hybrid molecules containing sulfa drugs, triazene linkers, and the classical primary sulfonamide chemotype may be considered an interesting example of effective enzyme inhibitors and important anticancer agents.

Establishment of a Prognostic Model for Pancreatic Cancer Based on Hypoxia-Related Genes

OBJECTIVES

Pancreatic cancer presents a formidable challenge with its aggressive nature and dismal prognosis, often hampered by elusive early symptoms. The tumor microenvironment (TME) emerges as a pivotal player in pancreatic cancer progression and treatment responses, characterized notably by hypoxia and immunosuppression. In this study, we aimed to identify hypoxia-related genes and develop a prognostic model for pancreatic cancer leveraging these genes.

METHODS

Through analysis of gene expression data from The Cancer Genome Atlas (TCGA) and subsequent GO/KEGG enrichment analysis, hypoxia-related pathways were identified. We constructed a prognostic model using lasso regression and validated it using an independent dataset.

RESULTS

Our results showed that expression levels of PLAU, SLC2A1, and CA9 exhibited significant associations with prognosis in pancreatic cancer. The prognostic model, built upon these genes, displayed robust predictive accuracy and was validated in an independent dataset. Furthermore, we found a correlation between the risk score of the prognostic model and clinical parameters of pancreatic cancer patients. At the same time, we also explored the relationship between the established hypoxia-related prognostic model and the immune microenvironment at the single-cell level. RT-qPCR results showed notable differences in the expression of hypoxia pathway-related genes between normal PANC-1 and hypoxic-treated PANC-1 cells.

CONCLUSION

Our study provides insights into the role of the hypoxic microenvironment in pancreatic cancer and offers a promising prognostic tool for clinical application.

Umbelliferone and Its Synthetic Derivatives as Suitable Molecules for the Development of Agents with Biological Activities: A Review of Their Pharmacological and Therapeutic Potential

Umbelliferone (UMB), known as 7-hydroxycoumarin, hydrangine, or skimmetine, is a naturally occurring coumarin in the plant kingdom, mainly from the Umbelliferae family that possesses a wide variety of pharmacological properties. In addition, the use of nanoparticles containing umbelliferone may improve anti-inflammatory or anticancer therapy. Also, its derivatives are endowed with great potential for therapeutic applications due to their broad spectrum of biological activities such as anti-inflammatory, antioxidant, neuroprotective, antipsychotic, antiepileptic, antidiabetic, antimicrobial, antiviral, and antiproliferative effects. Moreover, 7-hydroxycoumarin ligands have been implemented to develop 7-hydroxycoumarin-based metal complexes with improved pharmacological activity. Besides therapeutic applications, umbelliferone analogues have been designed as fluorescent probes for the detection of biologically important species, such as enzymes, lysosomes, and endosomes, or for monitoring cell processes and protein functions as well various diseases caused by an excess of hydrogen peroxide. Furthermore, 7-hydroxy-based chemosensors may serve as a highly selective tool for Al3+ and Hg2+ detection in biological systems. This review is devoted to a summary of the research on umbelliferone and its synthetic derivatives in terms of biological and pharmaceutical properties, especially those reported in the literature during the period of 2017-2023. Future potential applications of umbelliferone and its synthetic derivatives are presented.

Synthesis and biological evaluation of new 3-substituted coumarin derivatives as selective inhibitors of human carbonic anhydrase IX and XII

The Carbonic anhydrase isoforms IX and XII play a significant role in regulating the intracellular and extracellular pH in hypoxic tumours abetting the metastasis of solid tumours. Selective and potent inhibitors targeting carbonic anhydrase IX and XII reduce the activity of these isoforms in hypoxic tumours, representing an antitumor and antimetastatic mechanism. Coumarin-based derivatives are selective inhibitors of CA isoforms IX and XII. In this study, we report the design and synthesis of new 3-substituted coumarin derivatives with different functional moieties and their inhibitory activity against various carbonic anhydrase isoforms. We found that the tertiary sulphonamide derivative 6c showed selective inhibition against CA IX with IC₅₀ of 4.1 µM. Similarly, the carbothioamides 7c, 7b and oxime ether derivative 20a exhibited good inhibition against CA IX and CA XII. Additionally, the binding mode was predicted and validated using molecular docking and dynamic simulations.

3H-1,2-Benzoxaphosphepine 2-oxides as selective inhibitors of carbonic anhydrase IX and XII

The synthesis of 3H-1,2-benzoxaphosphepine 2-oxides and evaluation of their inhibitory activity against human carbonic anhydrase (hCA) isoforms I, II, IX, and XII are described. The target compounds were obtained via a concise synthesis from commercial salicylaldehydes and displayed low to sub-micromolar inhibition levels against the tumour-associated isoforms hCA IX and XII. All obtained benzoxaphosphepine 2-oxides possess remarkable selectivity for inhibition of hCA IX/XII over the off-target cytosolic hCA isoforms I and II, whose inhibition may lead to side effects.

Selenium-analogs based on natural sources as cancer-associated carbonic anhydrase isoforms IX and XII inhibitors

In the relentless search for new cancer treatments, organoselenium compounds, and carbonic anhydrase (CA) inhibitors have emerged as promising drug candidates. CA isoforms IX and XII are overexpressed in many types of cancer, and their inhibition is associated with potent antitumor/antimetastatic effects. Selenium-containing compounds, particularly selenols, have been shown to inhibit tumour-associated CA isoforms in the nanomolar range since the properties of the selenium atom favour binding to the active site of the enzyme. In this work, two series of selenoesters (1a-19a and 1b-19b), which gathered NSAIDs, carbo/heterocycles, and fragments from natural products, were evaluated against hCA I, II, IX, and XII. Indomethacin (17b) and flufenamic acid (19b) analogs exhibited selectivity for tumour-associated isoform IX in the low micromolar range. In summary, selenoesters that combine NSAIDs with fragments derived from natural sources have been developed as promising nonclassical inhibitors of the tumour-associated CA isoforms.

Design, synthesis, and biological investigation of selective human carbonic anhydrase II, IX, and XII inhibitors using 7-aryl/heteroaryl triazolopyrimidines bearing a sulfanilamide scaffold

A novel library of human carbonic anhydrase (hCA) inhibitors based on the 2-sulfanilamido[1,2,4]triazolo[1,5-a]pyrimidine skeleton modified at its 7-position was prepared by an efficient convergent procedure. These derivatives were evaluated in vitro for their inhibition properties against a representative panel of hCA isoforms (hCA I, II, IV, IX, and XII). The target tumour-associated isoforms hCA IX and XII were potently inhibited with KIs in the low nanomolar range of 5-96 nM and 4-72 nM, respectively. Compounds 1d, 1j, 1v, and 1x were the most potent hCA IX inhibitors with KIs of 5.1, 8.6, 4.7, and 5.1 nM, respectively. Along with derivatives 1d and 1j, compounds 1r and 1ab potently inhibited hCA XII isoform with KIs in a single-digit nanomolar range of 8.8, 5.4, 4.3, and 9.0 nM, respectively. Compounds 1e, 1m, and 1p exhibited the best selectivity against hCA IX and hCA XII isoforms over off-target hCA II, with selectivity indexes ranging from 5 to 14.

In silico study, synthesis, and antineoplastic evaluation of thiazole-based sulfonamide derivatives and their silver complexes with expected carbonic anhydrase inhibitory activity

This study aimed to design, synthesize, and evaluate the cytotoxic activity of novel thiazole-sulfanilamide derivatives, specifically compounds M3, M4, and M5, through molecular docking and biological assays. The synthesis utilized essential chemical compounds, including sulfanilamide, chloro-acetyl chloride, thiourea, derivatives of benzaldehyde, and silver nitrate. The docking study was carried out using Molecular Operating Environment (MOE) software, and cytotoxic activity was predicted by MTT assay. The synthesized compounds demonstrated a reduction in the viability of cancer cells. Compound M5 had an IC50 of 18.53 µg/ml against MCF-7 cells, comparable to the IC50 of cisplatin. Additionally, compounds M3 and M4 had higher S scores than acetazolamide, indicating greater binding affinity to the active pocket of the receptor. Incorporating the thiazole ring in the synthesized compound augmented their flexibility and affinity for binding to the receptor. The inclusion of the metal complex additionally heightened the compounds' capacity to impede cellular growth.

Targeting carbonic anhydrases for the management of hypoxic metastatic tumors

INTRODUCTION

Several isoforms of the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1) are connected with tumorigenesis. Hypoxic tumors overexpress CA IX and XII as a consequence of HIF activation cascade, being involved in pH regulation, metabolism, and metastases formation. Other isoforms (CA I, II, III, IV) were also reported to be present in some tumors.

AREAS COVERED

Some CA isoforms are biomarkers for disease progression or response to therapy. Inhibitors, antibodies, and other procedures for targeting these enzymes for the treatment of tumors/metastases are discussed. Sulfonamides and coumarins represent the most investigated classes of inhibitors, but carboxylates, selenium, and tellurium-containing inhibitors were also investigated. Hybrid drugs of CA inhibitors with other antitumor agents for multitargeted therapy were reported.

EXPERT OPINION

Targeting CAs present in solid or hematological tumors with selective, targeted inhibitors is a validated approach, which has been consolidated in the last years. A host of new preclinical data and several clinical trials of antibodies and small-molecule inhibitors are ongoing, which connected with the large number of new chemotypes/procedures discovered to be effective, may lead to a breakthrough in this therapeutic area. The scientific/patent literature has been searched for on PubMed, ScienceDirect, Espacenet, and PatentGuru, from 2018 to 2023.

6-Aminocoumarin oxime-ether/sulfonamides as selective hCA IX and XII inhibitors: Synthesis, evaluation, and molecular dynamics studies

Carbonic anhydrase isoforms IX and XII are overexpressed in hypoxic tumor cells regulating various physiological processes such as cell proliferation, invasion, and metastasis, resulting in the onset and spread of cancer. Selective inhibition of these enzymes is a promising strategy for anticancer therapy. Coumarin derivatives were identified as selective and potent inhibitors of these isoforms. This study reports 6-aminocoumarin sulfonamide and oxime ether derivatives linked through a chloroacetyl moiety tethered to piperazine and piperidone, respectively, showing selective inhibition against human carbonic anhydrase (hCA) IX and XII with Ki ranging from 0.51 to 1.18 µM and 0.89-4.43 µM. While the sulfonamide derivative 8a exhibited submicromolar inhibition against hCA IX and XII with Ki 0.89 and 0.51 µM, the oxime ether derivatives showed lower activity than the sulfonamides, with the compound 5n inhibiting hCA IX and hCA XII with a Ki of 1.055 and 0.70 µM, respectively. The above results demonstrate the potential of these derivatives as selective, potent inhibitors of carbonic anhydrase IX and XII and provide a foundation for further optimization and development as effective anticancer agents. Further, the binding mode of the synthesized derivatives in the active site were examined using molecular docking and dynamic simulation studies.

A simple yet multifaceted 90 years old, evergreen enzyme: Carbonic anhydrase, its inhibition and activation

Advances in the carbonic anhydrase (CA, EC 4.2.1.1) research over the last three decades are presented, with an emphasis on the deciphering of the activation mechanism, the development of isoform-selective inhibitors/ activators by the tail approach and their applications in the management of obesity, hypoxic tumors, neurological conditions, and as antiinfectives.

Cancer Bioenergetics and Tumor Microenvironments-Enhancing Chemotherapeutics and Targeting Resistant Niches through Nanosystems

Cancer is an impending bottleneck in the advanced scientific workflow to achieve diagnostic, prognostic, and therapeutic success. Most cancers are refractory to conventional diagnostic and chemotherapeutics due to their limited targetability, specificity, solubility, and side effects. The inherent ability of each cancer to evolve through various genetic and epigenetic transformations and metabolic reprogramming underlies therapeutic limitations. Though tumor microenvironments (TMEs) are quite well understood in some cancers, each microenvironment differs from the other in internal perturbations and metabolic skew thereby impeding the development of appropriate diagnostics, drugs, vaccines, and therapies. Cancer associated bioenergetics modulations regulate TME, angiogenesis, immune evasion, generation of resistant niches and tumor progression, and a thorough understanding is crucial to the development of metabolic therapies. However, this remains a missing element in cancer theranostics, necessitating the development of modalities that can be adapted for targetability, diagnostics and therapeutics. In this challenging scenario, nanomaterials are modular platforms for understanding TME and achieving successful theranostics. Several nanoscale particles have been successfully researched in animal models, quite a few have reached clinical trials, and some have achieved clinical success. Nanoparticles exhibit an intrinsic capability to interact with diverse biomolecules and modulate their functions. Furthermore, nanoparticles can be functionalized with receptors, modulators, and drugs to facilitate specific targeting with reduced toxicity. This review discusses the current understanding of different theranostic nanosystems, their synthesis, functionalization, and targetability for therapeutic modulation of bioenergetics, and metabolic reprogramming of the cancer microenvironment. We highlight the potential of nanosystems for enhanced chemotherapeutic success emphasizing the questions that remain unanswered.

Are tumour-associated carbonic anhydrases genuine therapeutic targets for photodynamic therapy?

INTRODUCTION

Photodynamic therapy (PDT) is a reactive oxygen species (ROS)-dependent treatment modality which has emerged as an alternative cancer therapy strategy. However, in solid tumors, the therapeutic efficacy of PDT is strongly reduced by hypoxia, a typical feature of many such tumors. The tumor-associated carbonic anhydrases IX (hCA IX) and XII (hCA XII), which are overexpressed under hypoxia are attractive, validated anticancer drug targets in solid tumors. Current challenges in therapeutic design of effective PDT systems aim to overcome the limitation of hypoxia by developing synergistic CA-targeted therapies combining photosensitizers and hCA IX/XII inhibitors.

AREA COVERED

In this review, the current literature on the use of hCA IX/XII inhibitors (CAi) for targeting photosensitizing chemical systems useful for PDT against hypoxic solid tumors is summarized, along with recent progress, challenges, and future prospects.

EXPERT OPINION

hCA IX/XII-focused photosensitizers have recently provided new generation of compounds of considerable potential. Proof of concept of in vivo efficacy studies suggested enhanced efficacy for CAi-PDT hybrid systems. Further research is needed to deepen our understanding of how hCA IX/hCA XII inhibition can enhance PDT and for obtaining more effective such derivatives.

Selective carbonic anhydrase IX and XII inhibitors based around a functionalized coumarin scaffold

Inhibition of specific carbonic anhydrase (CA) enzymes is a validated strategy for the development of agents to target cancer. The CA isoforms IX and XII are overexpressed in various human solid tumors wherein they play a critical role in regulating extracellular tumor acidification, proliferation, and progression. A series of novel sulfonamides based on the coumarin scaffold were designed, synthesized and characterized as potent and selective CA inhibitors. Selected compounds show significant activity and selectivity over CA I and CA II to target the tumor-associated CA IX and CA XII with high inhibition activity at the single digit nanomolar level. Twelve compounds were identified to be more potent compared with acetazolamide (AAZ) control to inhibit CA IX while one was also more potent than AAZ to inhibit CA XII. Compound 18f (Ki's = 955 nM, 515 nM, 21 nM and 5 nM for CA's I, II, IX, and XII, respectively) is highlighted as a novel CA IX and XII inhibitor for further development.

Hypoxia and Cancer: From Bench to Bedside

This Special Issue of Cancers (two original articles, five reviews), presented by international experts in tumor hypoxia, focuses on the role of hypoxia, or low oxygen levels, in the development and progression of cancer [...].

PET radiotracers and fluorescent probes for imaging human carbonic anhydrase IX and XII in hypoxic tumors

Positron emission tomography (PET) and fluorescent imaging play a pivotal role in medical diagnosis, biomedical oncologic research, and drug development process, which include identification of target location, target engagement, but also prove on mechanism of action or pharmacokinetics of new drug candidates. PET estimates physiological changes at the molecular level using specific radiotracers containing a short-lived positron emitting radionuclide such as fluorine-18 or carbon-11, whereas fluorescent imaging techniques use fluorescent probes labeled with suitable drug candidates for detection at the molecular level. The human carbonic anhydrase (hCA) isoforms IX and XII are overexpressed in hypoxic cancer cells, promoting tumor growth by regulating extra/intracellular pH, ferroptosis, and metabolism, being recognized as promising targets for anticancer theranostic agents. In this review, we have focused on PET radiotracers as well as fluorescent probes for diagnosis and treatment of tumors expressing hCA IX and hCA XII.

Inhibition Studies on Carbonic Anhydrase Isoforms I, II, IX, and XII with a Series of Sulfaguanidines

Two novel sulfaguanidine series, six N-(N,N'-dialkyl/dibenzyl-carbamimidoyl) benzenesulfonamide derivatives and nine N-(N-alkyl/benzyl-carbamimidoyl) benzenesulfonamide derivatives, were obtained by desulfidative amination of easily accessible dimethyl arylsulfonylcarbonimidodithioates under catalyst- and base-free conditions. The newly synthesized compounds were tested for the inhibition of four different isozymes of human carbonic anhydrase (hCA I, II, IX and XII, EC 4.2.1.1). Both series reported here were inactive against the off-target isozymes hCA I and II (K_i >100 μM). Interestingly, all investigated compounds inhibited both target isozymes hCA IX and XII in the submicromolar to micromolar ranges in which K_i values spanned from 0.168 to 0.921 μM against hCA IX and from 0.335 to 1.451 μM against hCA XII. The results indicated that N-(N-alkyl/benzyl-carbamimidoyl) benzenesulfonamides were slightly more potent inhibitors than N-(N,N'-dialkyl/dibenzyl-carbamimidoyl) benzenesulfonamides. Among the evaluated compounds, N-n-octyl-substituted N-carbamimidoylbenzenesulfonamide showed the most significant activity with a K_i value of 0.168 μM against hCA IX, which was four-fold more selective toward this isozyme versus hCA XII. Again, another derivative from N-(N-alkyl/benzyl-carbamimidoyl) benzenesulfonamide series, N-p-methylbenzyl-substituted N-carbamimidoylbenzenesulfonamide, demonstrated superior inhibitory activity against hCA XII with a K_i value of 0.335 μM.

Cu(ii)-BODIPY photosensitizer for CAIX overexpressed cancer stem cell therapy

Chemoresistance originating from cancer stem cells (CSCs) is a major cause of cancer treatment failure and highlights the need to develop CSC-targeting therapies. Although enormous progress in both photodynamic therapy (PDT) and chemodynamic therapy (CDT) has been made in recent decades, the efficacy of these modalities against CSC remains limited. Here, we report a new generation photosensitizer, CA9-BPS-Cu(ii), a system that combines three subunits within a single molecule, namely a copper catalyst for CDT, a boron dipyrromethene photosensitizer for PDT, and acetazolamide for CSC targeting via carbonic anhydrase-9 (CA9) binding. A therapeutic effect in MDA-MB-231 cells was observed that is ascribed to elevated oxidative stress mediated by a combined CDT/PDT effect, as well as through copper-catalysed glutathione oxidation. The CSC targeting ability of CA9-BPS-Cu(ii) was evident from the enhanced affinity of CA9-BPS-Cu(ii) towards CD133-positive MDA-MB-231 cells where CA9 is overexpressed vs. CD133-negative cells. Moreover, the efficacy of CA9-BPS-Cu(ii) was successfully demonstrated in a xenograft mouse tumour model.

Schiff bases as linker in the development of quinoline-sulfonamide hybrids as selective cancer-associated carbonic anhydrase isoforms IX/XII inhibitors: A new regioisomerism tactic

A novel set of quinoline tailored with the sulfonamide as zinc-binding group (ZBG) has been rationalized and synthesized as carbonic anhydrase (CA, EC 4.2.1.1) inhibitors. Such hybrids were decorated by a novel elongated imine linker with/without ethylene spacer with variable hydrophobic and lipophilic pockets. Therefore, a regioisomeric tactic has been established, most of which act as efficient inhibitors of the tumor-associated CA isoforms IX and XII. Interestingly, one hybrid 10b displayed an appreciable activity in MCF-7 cell line under normoxic condition (IC₅₀ of 8.42 µM) in comparison to the standard staurosporine (IC₅₀ = 5.34 µM) and excellent activity under hypoxic conditions (IC₅₀ = 1.56 µM) in comparison to staurosporine (IC₅₀ = 4.45 µM). Furthermore, hybrids 8a and 10b encouraged MCF-7 and MDA-MB-231 cell apoptosis alongside promising Bax/Bcl expression ratio change. Docking studies were also, performed and agreed with the biological results. Our SAR study suggested that our regiosiomerization tactic for the quinoline based-sulfonamide molecules led to effective inhibition of tumuor-relevant hCAs IX/XII.

Phytochemical Characterization of Pterocephalus frutescens with In-Silico Evaluation as Chemotherapeutic Medicine and Oral Pharmacokinetics Prediction Study

Virtual screening of the potential lead chemotherapeutic phytochemicals from medicinal plants has useful application in the field of in-silico modelling and computer-based drug design by orienting and scoring ligands in the active binding site of a target protein. The phytochemical investigation of the Pterocephalus frutescens extract in n-butanol resulted in the isolation and structure elucidation of three iridoids and four flavonoids which were identified as Geniposide (1), Geniposidic acid (2), Nepetanudoside C (3), Isovitexin (4), Luteolin-7-O-glucoside (5) Isoorientin (6) and Orientin (7), respectively. Molecular docking studies were used to compare the binding energies of the isolated phytochemicals at four biological cancer-relevant targets; namely, aromatase, carbonic anhydrase IX, fatty acid synthase, and topoisomerase II-DNA complex. The docking study concluded that the isolated compounds have promising cytotoxic activities, in particular, Luteolin-7-O-glucoside (5) and Orientin (7) which exhibited high binding affinities among the isolated compounds at the active sites of the target enzymes; Aromatase (−8.73 Kcal/mol), and Carbonic anhydrase IX (−8.92 Kcal/mol), respectively, surpassing the corresponding binding scores of the co-crystallized ligands and the reference drugs at these target enzymes. Additionally, among the isolated compounds, Luteolin-7-O-glucoside (5) showed the most outstanding binding affinities at the active sites of the target enzymes; Fatty acid synthase, and Topisomerase II-DNA complex with binding scores of −6.82, and −7.99 Kcal/mol, respectively. Finally, the SwissADME online web tool predicted that most of these compounds possessed acceptable oral bioavailability and drug likeness characteristics.

SLC-0111, an inhibitor of carbonic anhydrase IX, attenuates hepatoblastoma cell viability and migration

Background

In response to hypoxia, tumor cells undergo transcriptional reprogramming including upregulation of carbonic anhydrase (CA) IX, a metalloenzyme that maintains acid-base balance. CAIX overexpression has been shown to correlate with poor prognosis in various cancers, but the role of this CA isoform in hepatoblastoma (HB) has not been examined.

Methods

We surveyed the expression of CAIX in HB specimens and assessed the impact of SLC-0111, a CAIX inhibitor, on cultured HB cells in normoxic and hypoxic conditions.

Results

CAIX immunoreactivity was detected in 15 out of 21 archival pathology HB specimens. The CAIX-positive cells clustered in the middle of viable tumor tissue or next to necrotic areas. Tissue expression of CAIX mRNA was associated with metastasis and poor clinical outcome of HB. Hypoxia induced a striking upregulation of CAIX mRNA and protein in three HB cell models: the immortalized human HB cell line HUH6 and patient xenograft-derived lines HB-295 and HB-303. Administration of SLC-0111 abrogated the hypoxia-induced upregulation of CAIX and decreased HB cell viability, both in monolayer and spheroid cultures. In addition, SLC-0111 reduced HB cell motility in a wound healing assay. Transcriptomic changes triggered by SLC-0111 administration differed under normoxic vs. hypoxic conditions, although SLC-0111 elicited upregulation of several tumor suppressor genes under both conditions.

Conclusion

Hypoxia induces CAIX expression in HB cells, and the CAIX inhibitor SLC-0111 has in vitro activity against these malignant cells.

Design, synthesis, biological evaluation and crystal structure determination of dual modulators of carbonic anhydrases and estrogen receptors

Multi-target compounds have become increasingly important for the development of safer and more effective drug candidates. In this work, we devised a combined ligand-based and structure-based multi-target repurposing strategy and applied it to a series of hexahydrocyclopenta[c]quinoline compounds synthesized previously. The in silico analyses identified human Carbonic Anhydrases (hCA) and Estrogen Receptors (ER) as top scoring candidates for dual modulation. hCA isoforms IX and XII, and ER subtypes ER⍺ and/or ERβ are co-expressed in various cancer cell types, including breast and prostate cancer cells. ER⍺ is the primary target of anti-estrogen therapy in breast cancer, and the hCA IX isoform is a therapeutic target in triple-negative breast cancer. ER⍺-mediated transcriptional programs and hCA activity in cancer cells promote favorable microenvironments for cell proliferation. Interestingly, several lines of evidence indicate that the combined modulation of these two targets may provide significant therapeutic benefits. Moving from these first results, two additional hexahydrocyclopenta[c]quinoline derivatives bearing a sulfonamide zinc binding group (hCA) and a phenolic hydroxyl (ER) pharmacophoric group placed at the appropriate locations were designed and synthesized. Interestingly, these compounds were able to directly modulate the activities of both hCA and ER targets. In cell-based assays, they inhibited proliferation of breast and prostate cancer cells with micromolar potency and cell type-selective efficacy. The compounds inhibited hCA activity with nanomolar potency and isoform-selectivity. In transactivation assays, they reduced estrogen-driven ER activity with micro-molar potency. Finally, crystal structures of the synthesized ligands in complex with the two targets revealed that the compounds bind directly to the hCA active site, as well as to the ER ligand-binding domain, providing structural explanation to the observed activity and a rationale for optimization of their dual activity. To the best of our knowledge, this work describes the design, synthesis and biological characterization of the first dual modulators of hCA and ER, laying the ground for the structure-based optimization of their multi-target activity.

Inhibition of Bone Marrow-Mesenchymal Stem Cell-Induced Carbonic Anhydrase IX Potentiates Chemotherapy Efficacy in Triple-Negative Breast Cancer Cells

Conventional chemotherapy represents the main systemic treatment used for triple-negative breast cancer (TNBC) patients, although many of them develop drug resistance. The hypoxic TME is the crucial driver in the onset of insensitivity to chemotherapy. In this research, we elucidated the role played by bone marrow-derived mesenchymal stem cells (BM-MSCs) in reducing cisplatin effects in TNBC. BT-549 and MDA-MB-231 cells, grown under hypoxic conditions in the presence of conditioned medium obtained from BM-MSCs (CM-MSCs), showed a strong cisplatin insensitivity and increased expression levels of carbonic anhydrase IX (CA IX). Therefore, we inhibited CM-MSC-induced CA IX by SLC-0111 to potentiate chemotherapy efficacy in TNBC cells. Our results showed that CM-MSCs under hypoxic conditions caused an increase in the ability of TNBC cells to form vascular structures, migrate and invade Matrigel. Cell treatment with cisplatin plus SLC-0111 was able to block these mechanisms, as well as the signaling pathways underlying them, such as p-AKT, p-ERK, CD44, MMP-2, vimentin, β-catenin, and N-cadherin, more effectively than treatment with single agents. In addition, a significant enhancement of apoptosis assessed by annexin V, caspase-3 expression and activity was also shown. Taken together, our results demonstrated the possibility, through CA IX inhibition, of returning TNBC cells to a more chemosensitive state.

Effect of tumor microenvironment on ferroptosis: inhibition or promotion

Ferroptosis is a type of lipid peroxidation-induced, iron-dependent programmed cell death. Emerging evidence suggests that ferroptosis is intimately connected to tumorigenesis, development, treatment and plays a major role in tumor immune regulation. This study focused on the connection between ferroptosis and immune regulation, which may offer a theoretical basis for targeting ferroptosis and tumor immunotherapy.

Design and synthesis of benzothiazole-based SLC-0111 analogues as new inhibitors for the cancer-associated carbonic anhydrase isoforms IX and XII

In this work, different series of benzothiazole-based sulphonamides 8a-c, 10, 12, 16a-b and carboxylic acids 14a-c were developed as novel SLC-0111 analogues with the goal of generating potent carbonic anhydrase (CA) inhibitors. The adopted strategy involved replacing the 4-fluorophenyl tail in SLC-0111 with a benzothiazole motif that attached to the ureido linker to produce compounds 8c and its regioisomers 8a-b. In addition, the ureido spacer was elongated by methylene or ethylene groups to afford the counterparts 10 and 12. In turn, the primary sulfamoyl zinc binding group (ZBG) was either substituted or replaced by carboxylic acid functionality in order to provide the secondary sulphonamide-based SLC-0111 analogues 16a-b, and the carboxylic acid derivatives 14a-c, respectively. All compounds (8a-c, 10, 12, 14a-c and 16a-b) were tested for their ability to inhibit CA isoforms CA I, II, IX and XII. Additionally, the in vitro anticancer properties of the developed CAIs were evaluated.

Indoline-5-Sulfonamides: A Role of the Core in Inhibition of Cancer-Related Carbonic Anhydrases, Antiproliferative Activity and Circumventing of Multidrug Resistance

The overexpression and activity of carbonic anhydrase (CA, EC 4.2.1.1) isoforms CA IX and CA XII promote the accumulation of exceeding protons and acidosis in the extracellular tumor environment. Sulfonamides are effective inhibitors of most families of CAs. In this study, using scaffold-hopping, indoline-5-sulfonamide analogs 4a-u of the CA IX-selective inhibitor 3 were designed and synthesized to evaluate their biological properties. 1-Acylated indoline-5-sulfonamides demonstrated inhibitory activity against tumor-associated CA IX and XII with K_I values up to 132.8 nM and 41.3 nM. Compound 4f, as one of the most potent inhibitors of CA IX and XII, exhibits hypoxic selectivity, suppressing the growth of MCF7 cells at 12.9 µM, and causes partial inhibition of hypoxia-induced CA IX expression in A431 skin cancer cells. 4e and 4f reverse chemoresistance to doxorubicin of K562/4 with overexpression of P-gp.

Design, Synthesis and Biological Assessment of Rhodanine-Linked Benzenesulfonamide Derivatives as Selective and Potent Human Carbonic Anhydrase Inhibitors

A novel series of twenty-five rhodamine-linked benzenesulfonamide derivatives (7a-u and 9a-d) were synthesized and screened for their inhibitory action against four physiologically relevant human (h) carbonic anhydrase (CA) isoforms, namely hCA I, hCA II, hCA IX, and hCA XII. All the synthesized molecules showed good to excellent inhibition against all the tested isoforms in the nanomolar range due to the presence of the sulfonamide as a zinc binding group. The target compounds were developed from indol-3-ylchalcone-linked benzenesulfonamide where the indol-3-ylchalcone moiety was replaced with rhodanine-linked aldehydes or isatins to improve the inhibition. Interestingly, the molecules were slightly more selective towards hCA IX and XII compared to hCA I and II. The most potent and efficient ones against hCA I were 7h (K_I 22.4 nM) and 9d (K_I 35.8 nM) compared to the standard drug AAZ (K_I 250.0 nM), whereas in case of hCA II inhibition, the derivatives containing the isatin nucleus as a tail were preferred. Collectively, all compounds were endowed with better inhibition against hCA IX compared to AAZ (K_I 25.8 nM) as well as strong potency against hCA XII. Finally, these newly synthesized molecules could be taken as potential leads for the development of isoform selective hCA IX and XII inhibitors.