Tumour-associated Isoforms Research Articles

Design, synthesis, and carbonic anhydrase inhibition activities of Schiff bases incorporating benzenesulfonamide scaffold: Molecular docking application

In this study, The inhibitory actions of human carbonic anhydrase (CA, EC 4.2.1.1) (hCA) isoforms I, II, IX, and XII are being examined using recently synthesized substituted hydroxyl Schiff derivatives based on the quinazoline scaffold 4–22. Quinazolines 2, 3, 4, 5, 7, 10, 15, and 18 reduce the activity of hCA I isoform effectively to a Ki of 87.6–692.3 nM, which is nearly equivalent to or more potent than that of the standard drug AAZ (Ki, 250.0 nM). Similarly, quinazolines 2, 3, and 5 and quinazoline 14 effectively decrease the inhibitory activity of the hCA II isoform to a KI of 16.9–29.7 nM, comparable to that of AAZ (Ki, 12.0 nM). The hCA IX isoform activity is substantially diminished by quinazolines 2–12 and 14–21 (Ki, 8.9–88.3 nM against AAZ (Ki, 25.0 nM). Further, the activity of the hCA XII isoform is markedly inhibited by the quinazolines 3, 5, 7, 14, and 16 (Ki, 5.4–19.5 nM). Significant selectivity levels are demonstrated for inhibiting tumour-associated isoforms hCA IX over hCAI, for sulfonamide derivatives 6–15 (SI; 10.68–186.29), and 17–22 (SI; 12.52–57.65) compared to AAZ (SI; 10.0). Sulfonamide derivatives 4–22 (SI; 0.50–20.77) demonstrated a unique selectivity in the concurrent inhibition of hCA IX over hCA II compared to AAZ (SI; 0.48). Simultaneously, benzenesulfonamide derivative 14 revealed excellent selectivity for inhibiting hCA XII over hCA I (SI; 60.35), whereas compounds 5–8, 12–14, 16, and 18–22 demonstrated remarkable selectivity for hCA XII inhibitory activity over hCA II (SI; 2.09–7.27) compared to AAZ (SI; 43.86 and 2.10, respectively). Molecular docking studies additionally support 8 to hCA IX and XII binding, thus indicating its potential as a lead compound for inhibitor development.

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 K Is 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 K Is 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 K Is 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.

Effect of hydrophobic extension of aryl enaminones and pyrazole-linked compounds combined with sulphonamide, sulfaguanidine, or carboxylic acid functionalities on carbonic anhydrase inhibitory potency and selectivity

Design and synthesis of three novel series of aryl enaminones (3a–f and 5a–c) and pyrazole (4a-c) linked compounds with sulphonamides, sulfaguanidine, or carboxylic acid functionalities were reported as carbonic anhydrase inhibitors (CAIs) using the “tail approach” strategy in their design to achieve the most variable amino acids in the middle/outer rims of the hCAs active site. The synthesised compounds were assessed in vitro for their inhibitory activity against the following human (h) isoforms, hCA I, II, IX, and XII using stopped-flow CO2 hydrase assay. Enaminone sulphonamide derivatives (3a–c) potently inhibited the target tumour-associated isoforms hCA IX and hCA XII (KIs 26.2–63.7 nM) and hence compounds 3a and 3c were further screened for their in vitro cytotoxic activity against MCF-7 and MDA-MB-231 cancer cell lines under normoxic and hypoxic conditions. Derivative 3c showed comparable potency against both MCF-7 and MDA-MB-231 cancer cell lines under both normoxic ((IC50 = 4.918 and 12.27 µM, respectively) and hypoxic (IC50 = 1.689 and 5.898 µM, respectively) conditions compared to the reference drug doxorubicin under normoxic (IC50 = 3.386 and 4.269 µM, respectively) and hypoxic conditions (IC50 = 1.368 and 2.62 µM, respectively). Cell cycle analysis and Annexin V-FITC and propidium iodide double staining methods were performed to reinforce the assumption that 3c may act as a cytotoxic agent through the induction of apoptosis in MCF-7 cancer cells.

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.

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.

Design and synthesis of some new benzoylthioureido benzenesulfonamide derivatives and their analogues as carbonic anhydrase inhibitors

The present investigation reports the design and synthesis of three series of benzoylthioureido derivatives bearing either benzenesulfonamide 7a–f, benzoic acid 8a–f or ethylbenzoate 9a–f moieties. The synthesised compounds were screened for their carbonic anhydrase inhibitory activity (CAI) against four isoforms hCA I, II, IX, and XII. Compounds 7a, 7b, 7c, and 7f exhibited a potent inhibitory activity towards hCAI (K is = 58.20, 56.30, 33.00, and 43.00 nM), respectively compared to acetazolamide (AAZ) and SLC-0111 (K is = 250.00 and 5080.00 nM). Compounds 7a, 7b, 7c, 7e, and 7f elicited selectivity over h CA II (K is = 2.50, 2.10, 56.60,39.60 and 39.00 nM) respectively, relative to AAZ and SLC-0111(K is = 12.10 and 960.00 nM). Also, compounds 7c, 7f, and 9e displayed selectivity against the tumour-associated isoform hCA IX (K is = 31.20, 30.00 and 29.00 nM) respectively, compared to AAZ and SLC-0111 (K is = 25.70 and 45.00 nM). Additionally, compounds 8a and 8f revealed a moderate to superior selectivity towards hCAXII (K is = 17.00 and 11.00 nM) relative to AAZ and SLC-0111(K is = 5.70 and 45.00 nM). Molecular docking and ADME prediction studies were performed on the most active compounds to shed light on their interaction with the hot spots of the active site of CA isoforms, in addition to prediction of their pharmacokinetic and physicochemical properties.

Selective inhibition of carbonic anhydrase IX by sulphonylated 1,2,3-triazole incorporated benzenesulphonamides capable of inducing apoptosis

In search of selective carbonic anhydrase (CA) IX inhibitors endowed with apoptotic inducing properties, we designed and synthesised two subsets of 4- and 3-(5-aryl-(4-phenylsulphonyl)-1H-1,2,3-triazol-1-yl)benzenesulphonamides. All compounds were assayed for human carbonic anhydrase (hCA) isoforms I, II, IV, and IX inhibition. Isoforms hCA I and hCA IV were weakly inhibited by most of the synthesised compounds. Many four-substituted benzenesulphonamides displayed low nanomolar inhibition against isoform hCA II, unlike the three-substituted analogues. All target compounds exhibited good inhibition profile with KI values ranging from 16.4 to 66.0 nM against tumour-associated isoform hCA IX. Some selective and potent inhibitors of hCA IX were assayed for in vitro apoptotic induction in goat testicular cells. Compounds 10d and 10h showed interesting apoptotic induction potential. The present study may provide insights into a strategy for the design of novel anticancer agents based on hCA inhibitors endowed with apoptotic interference.

The inhibitory effect of boric acid on hypoxia-regulated tumour-associated carbonic anhydrase IX

Carbonic anhydrases (EC 4.2.1.1) catalyse the reversible hydration of CO2 into bicarbonate and protons. As a hypoxia-sensitive and tumour-associated isoform, isoform CA IX, is significantly overexpressed in various malignancies, being a validated target for new anticancer/antimetastatic drugs. A multitude of studies has shown that CA IX inhibition decreases cancer cell proliferation and metastasis through pHe/pHi modulation and enhancement of ferroptosis among others. Numerous studies demonstrated increased efficacy of cytotoxic drugs combined with CA inhibitors (CAIs) in various cancer types. We tested the inhibitory effect of boric acid (BA), an inorganic Lewis acid, on CA IX as well as other isoforms (CA I, II, and XII). BA acted as a millimolar in vitro CAI, decreased proliferation of two cancer cell lines, although not strong correlations between the in vitro inhibition and in vivo effects were observed. The mechanism of antiproliferative action of BA should be investigated in more detail.

Synthesis, Crystal Structure, Inhibitory Activity and Molecular Docking of Coumarins/Sulfonamides Containing Triazolyl Pyridine Moiety as Potent Selective Carbonic Anhydrase IX and XII Inhibitors

In this work, two classes of Carbonic Anhydrase (CA) inhibitors, sulfonamide and coumarin derivatives linked to pyta moiety (2a-b) and their corresponding rhenium complexes (3a-b), were designed. These compounds were synthesized and fully characterized by classical analytical methods and X-ray diffraction. All the synthesized compounds were evaluated for their inhibitory activity against the hCA isoforms I, II, IX and XII. They exhibited high inhibitory activities in the range of nanomolar for both hCA IX and hCA XII isoforms. The sulfonamide compound 2a showed the strongest inhibition against the tumour-associated hCA IX isoform with a Ki of 11.7 nM. The tumour-associated isoforms hCA IX and hCA XII were selectively inhibited by all the coumarin derivatives, with inhibition constants ranging from 12.7 nM (2b) to 44.5 nM (3b), while the hCA I and II isoforms were slightly inhibited (in the micromolar range), as expected. In terms of selectivity, compared to previously published rhenium complex-based CA inhibitors, complex 3b showed one of the highest selectivities against hCA IX and hCA XII compared to the off-target isoforms hCA I and hCA II, making it a potential anti-cancer drug candidate. Molecular docking calculations were performed to investigate the inhibition profiles of the investigated compounds at the tumour-associated hCA IX active site and to rationalize our results.

Coumarins from Magydaris pastinacea as inhibitors of the tumour-associated carbonic anhydrases IX and XII: isolation, biological studies and in silico evaluation

In an in vitro screening for human carbonic anhydrase (hCA) inhibiting agents from higher plants, the petroleum ether and ethyl acetate extracts of Magydaris pastinacea seeds selectively inhibited hCA IX and hCA XII isoforms. The phytochemical investigation of the extracts led to the isolation of ten linear furocoumarins (1–10), four simple coumarins (12–15) and a new angular dihydrofurocoumarin (11). The structures of the isolated compounds were elucidated based on 1 D and 2 D NMR, MS, and ECD data analysis. All isolated compounds were inactive towards the ubiquitous cytosolic isoform hCA I and II (K i > 10,000 nM) while they were significantly active against the tumour-associated isoforms hCA IX and XII. Umbelliprenin was the most potent coumarin inhibiting hCA XII isoform with a K i of 5.7 nM. The cytotoxicity of the most interesting compounds on HeLa cancer cells was also investigated.

Aryl derivatives of 3H-1,2-benzoxathiepine 2,2-dioxide as carbonic anhydrase inhibitors

A new series of homosulfocoumarins (3H-1,2-benzoxathiepine 2,2-dioxides) possessing various substitution patterns and moieties in the 7, 8 or 9 position of the heterocylic ring were prepared by original procedures and investigated for the inhibition of four physiologically relevant carbonic anhydrase (CA, EC 4.2.1.1) isoforms, the human (h) hCA I, II, IX and XII. The 8-substituted homosulfocoumarins were the most effective hCA IX/XII inhibitors followed by the 7-substituted derivatives, whereas the substitution pattern in position 9 led to less effective binders for the transmembrane, tumour-associated isoforms IX/XII. The cytosolic isoforms hCA I and II were not inhibited by these compounds, similar to the sulfocoumarins/coumarins investigated earlier. As hCA IX and XII are validated anti-tumour targets, with one sulphonamide (SLC-0111) in Phase Ib/II clinical trials, finding derivatives with better selectivity for inhibiting the tumour-associated isoforms over the cytosolic ones, as the homosulfocoumarins reported here, is of crucial importance.

Discovery of novel 1,3-diaryltriazene sulfonamides as carbonic anhydrase I, II, VII, and IX inhibitors

A series of new 1,3-diaryltriazene sulfonamides was synthesised by reaction of diazonium salt of metanilamide (3-aminobenzene sulfonamide) with substituted aromatic amines. The obtained new compounds were assayed as inhibitors of four physiologically and pharmacologically relevant human (h) isoforms of carbonic anhydrases (CA, EC 4.2.1.1), specifically, hCA I, hCA II, and hCA VII (cytosolic isoforms), as well as the tumour-associated membrane-bound isoform hCA IX. All isoforms investigated here were inhibited by the newly synthesised 1,3-diaryltriazene sulfonamide derivatives from the micromolar to the nanomolar range. The cytosolic isoforms were inhibited with Kis in the range of 92.3–8371.1 nM (hCA I), 4.3–9194.0 nM (hCA II), and 15.6–9477.8 nM (hCA VII), respectively. For the membrane-bound tumour-associated isoform hCA IX, the KI-s ranged between 50.8 and 9268.5 nM. The structure–activity relationship (SAR) with these newly synthesised metanilamide derivatives are discussed in detail.

Synthesis, biological activity and multiscale molecular modeling studies for coumaryl-carboxamide derivatives as selective carbonic anhydrase IX inhibitors

New coumaryl-carboxamide derivatives with the thiourea moiety as a linker between the alkyl chains and/or the heterocycle nucleus were synthesized and their inhibitory activity against the human carbonic anhydrase (hCA) isoforms hCA I, II, VII and IX were evaluated. While the hCA I, II and VII isoforms were not inhibited by the investigated compounds, the tumour-associated isoform hCA IX was inhibited in the high nanomolar range. 2-Oxo-N-((2-(pyrrolidin-1-yl)ethyl)carbamothioyl)-2H-chromene-3-carboxamide (e11) exhibited a selective inhibitory action against hCA IX with the Ki of 107.9 nM. In order to better understand the inhibitory profiles of studied molecules, multiscale molecular modeling approaches were used. Different molecular docking algorithms were used to investigate binding poses and predicted binding energies of studied compounds at the active sites of the CA I, II, VII and IX isoforms.

Significant elevation of tumour-associated isoforms of soluble CD44 in serum of normal individuals caused by cigarette smoking.

While performing a prospective study on sCD44 variant isoforms as tumour markers in certain malignancies, we detected relevant differences in the control group between non-smokers and smokers. For a detailed evaluation of these findings, serum levels of sCD44 variant proteins, including sequences encoded by exon v5 and exon v6, respectively, were adjusted to sex, age and smoking habit. We were able to demonstrate a significant elevation of serum levels of sCD44v5 and sCD44v6 in normal individuals due to cigarette smoking (non-smokers to smokers: sCD44v5: 33 +/- 11 microg/l to 62 +/- 30 microg/l; sCD44v6: 142 +/- 34 microg/l to 232 +/- 86 microg/l). Stepwise multiple linear regression analysis of the concentrations of sCD44v5 and sCD44v6 on the possible influence factors sex, age and smoking habit revealed cigarette smoking as the only factor influencing these isoforms (both p << 0.001). Further investigations have to elucidate a possible clinical importance of these findings in smokers. However, in patients with suspected or proven malignancy the diagnostic specifity of sCD44v5 and sCD44v6 is diminished due to this observation.