Design, synthesis, and biological evaluation of furan-bearing pyrazolo[3,4-b]pyridines as novel inhibitors of CDK2 and P53-MDM2 protein-protein interaction

Development of Benzothiazole-grafted Pyrazolo[1,5-a]pyrimidines as new CDK2 inhibitors and anti-prostate cancer agents

In the current medical era, CDK2 kinase has emerged as a promising target in the global fight against cancer. Recent research reported the overexpression of CDK2 in prostate cancer cells, which highlighted the potential of CDK2 inhibition as a practical therapeutic approach for this disease that stands out as a challenging global health issue. On account of their interesting biological activities, especially anti-cancer properties, the two privileged scaffolds benzothiazole and pyrazolo[1,5-a]pyrimidine were utilized in this study to develop three series of 16 novel small molecules (8a-k, 12a-c, and 14a-b) as potential anti-prostate cancer agents targeting CDK2. The synthesized derivatives were assessed for cytotoxic effects against two prostate cancer cell lines, DU-145 and PC-3. Compounds 8f, 12c, and 14b exhibited the highest anti-cancer activity. Further investigation showed that these molecules inhibit critical cell cycle regulators by arresting DU-145 cells at the G0/G1 phase. Apoptosis induction was verified using Annexin V-FITC/Propidium iodide (PI) assays, which indicated a noteworthy apoptosis level in DU-145 cells. The compounds were validated as CDK2 inhibitors via in-vitro assays, with 8f demonstrating the highest potency, exceeding that of the reference drug Roscovitine. Molecular docking studies revealed substantial binding affinities of compounds 8f, 12c, and 14b to the ATP-binding site of CDK2, supported by essential hydrogen bonding and hydrophobic interactions. Overall, these study's findings indicate the potential of these benzothiazole-grafted pyrazolo[1,5-a]pyrimidines as effective therapeutic agents for prostate cancer.

Design, synthesis and biological evaluation of pyrazolo[3,4-b]pyridine derivatives as dual CDK2/PIM1 inhibitors with potent anti-cancer activity and selectivity

The discovery of novel, selective inhibitors targeting CDK2 and PIM1 kinases, which regulate cell survival, proliferation, and treatment resistance, is crucial for advancing cancer therapy. This study reports the design, synthesis, and biological evaluation of three novel pyrazolo[3,4-b]pyridine derivatives (6a-c), confirmed via spectral analyses. These compounds were assessed for anti-cancer activity against breast, colon, liver, and cervical cancers using the MTT assay. Among the tested compounds, 6b exhibited superior efficacy, with higher selectivity indices for HCT-116 (15.05) and HepG2 (9.88) compared to the reference drug staurosporine. Mechanistic studies revealed that 6b induced apoptosis (63.04-fold increase) and arrested the cell cycle at the G0-G1 phase, highlighting its anti-proliferative effects. In an in-vivo solid Ehrlich carcinoma (SEC) mouse model, compound 6b significantly reduced tumor weight and volume, exceeding the efficacy of doxorubicin. Additionally, 6b potently inhibited CDK2 and PIM1 kinases (IC50: 0.27 and 0.67 µM, respectively) and reduced tumor-promoting TNF-alpha expression, as confirmed by histopathological and immunohistochemical studies. Computational analyses, including molecular docking, molecular dynamics simulations, and DFT calculations, provided insights into the binding stability and interaction mechanisms of 6b with CDK2 and PIM1, while in-silico pharmacokinetic and toxicity evaluations confirmed its favorable drug-like profile and safety. This study highlights compound 6b as a promising dual CDK2/PIM1 inhibitor with potent anti-cancer activity and selectivity, paving the way for its further optimization and development as a lead molecule in cancer therapy.

Bioactive Fused Pyrazoles Inspired by the Adaptability of 5-Aminopyrazole Derivatives: Recent Review

Heterocyclic compounds, especially those containing the pyrazole moiety, are highly significant in organic chemistry and possess remarkable and diverse biological properties. The 5-aminopyrazole derivatives are key starting materials for the synthesis of numerous bioactive compounds such as pyrazolopyridine, pyrazolopyrimidine, pyrazoloquinazoline, and pyrazolotriazine derivatives. Many compounds inspired by the 5-aminopyrazole derivatives possess a wide spectrum of biological activities and medicinal applications such as antioxidants, anticancer agents, enzyme inhibitors, antimicrobials, and anti-tuberculosis activities. This review summarizes the recently reported synthesis methods and biological activities of fused pyrazole and pyrazole-based derivatives based on 5-aminopyrazole compounds within the last 5 years (2020 to present). One of the important goals of this review is to illustrate future strategies for the design, development, and utilization of pyrazole products as potent drugs.

Molecular docking, DFT and antiproliferative properties of 4-(3,4-dimethoxyphenyl)-3-(4-methoxyphenyl)-1-phenyl-1H-pyrazolo[3,4-b]pyridine as potent anticancer agent with CDK2 and PIM1 inhibition potency

Due to the limited effeteness and safety concerns associated with current cancer treatments, there is a pressing need to develop novel therapeutic agents. 4-(3,4-Dimethoxyphenyl)-3-(4-methoxyphenyl)-1-phenyl-1H-pyrazolo[3,4-b]pyridine (3) was synthesized and Initially screened on 59 cancer cell lines showed promising anticancer activity, so, it was chosen for a 5-dose experiment by the NCI/USA. The GI50 values ranged from 1.04 to 8.02 μM on the entire nine panels (57 cell lines), with a GI50 of 2.70 μM for (MG-MID) panel, indicating an encouraging action. To further explore the molecular attributes of compound 3, we optimized its structure using DFT with the B3LYP/6-31 + + G(d,p) basis set. We have considered vibrational analysis, bond lengths and angles, FMOs, and MEP for the structure. Additionally, pharmacokinetic assessments were conducted using various in-silico platforms to evaluate the compound safety. A molecular modeling study created a kinase profile on 44 different kinases. This allowed us to study our compound's binding affinity to these kinases and compare it to the co-crystallized one. Our findings revealed compound 3 exhibited better binding for half of the tested kinases, suggesting its potential as a multi-kinase inhibitor. To further validate our computational results, we tested compound 3 for its inhibitory effects on CDK2 and PIM1. Compound 3 exhibited an IC50 of 0.30 µM for CDK2 inhibition, making it five times less active than Roscovitine, which has an IC50 of 0.06 µM. However, compound 3 demonstrated slightly better inhibition of PIM1 compared to Staurosporine. These findings suggest that compound 3 is a promising anticancer agent with the potential for further development into a highly active compound.

Molecular docking approach for the design and synthesis of new pyrazolopyrimidine analogs of roscovitine as potential CDK2 inhibitors endowed with pronounced anticancer activity

Cyclin-dependent kinase 2 (CDK2) is a vital protein for controlling cell cycle progression that is critically associated with various malignancies and its inhibition could offer a convenient therapeutic approach in designing anticancer remedies. Consequently, this study aimed to design and synthesize new CDK2 inhibitors featuring roscovitine as a template model. The purine ring of roscovitine was bioisosterically replaced with the pyrazolo[3,4-d]pyrimidine scaffold, in addition to some modifications in the side chains. A preliminary molecular docking study for the target chemotypes in the CDK2 binding domain revealed their ability to accomplish similar binding patterns and interactions to that of the lead compound roscovitine. Afterwards, synthesis of the new derivatives was accomplished. Then, the initial anticancer screening at a single dose by the NCI revealed that compounds 7a, 9c, 11c, 17a and 17b achieved the highest GI% values reaching up to 150 % indicating their remarkable activity. These derivatives were subsequently selected to undertake five-dose testing, where compounds 7a, 9c, 11c and 17a unveiled the most pronounced activity against almost the full panel with GI50 ranges; 1.41-28.2, 0.116-2.39, 0.578-60.6 and 1.75-42.4 µM, respectively and full panel GI50 (MG-MID); 8.24, 0.6, 2.46 and 6.84 µM, respectively. CDK2 inhibition assay presented compounds 7a and 9c as the most potent inhibitors with IC50 values of 0.262 and 0.281 µM, respectively which are nearly 2.4 folds higher than the reference ligand roscovitine (IC50 = 0.641 µM). Besides, flow cytometric analysis on the most susceptible and safe cell lines depicted that 7a caused cell cycle arrest at G1/S phase in renal cancer cell line (RXF393) while 9c led to cell growth arrest at S phase in breast cancer cell line (T-47D) along with pronounced apoptotic induction in the mentioned cell lines. These findings afforded new anticancer pyrazolo[3,4-d]pyrimidine, roscovitine analogs, acting via CDK2 inhibition.

Exploring new quinazolin-4(3H)-one derivatives as CDK2 inhibitors: Design, synthesis, and anticancer evaluation

In the present work, five series of new 2,3-disubstituted quinazolin-4(3H)-ones 4a-c, 5a-d, 6a-g, 7a,b, and 9a-c were designed, synthesized, and screened in vitro for their cytotoxic activity against 60 cancer cell lines by the National Cancer Institute, USA. Five candidates 4c, 6a, 6b, 6d, and 6g revealed promising cytotoxicity with significant percentage growth inhibition in the range of 81.98%-96.45% against the central nervous system (CNS) (SNB-19), melanoma (MDA-MB-435), and non-small cell lung cancer (HOP-62) cell lines. The in vitro cytotoxic half maximal inhibitory concentration (IC50 ) values for the most active compounds 4c, 6a, 6b, 6d, and 6g against the most sensitive cell lines were evaluated. Additionally, screening their cyclin-dependent kinase 2 (CDK2) inhibitory activity was performed. Ortho-chloro-benzylideneamino derivative 6b emerged as the most potent compound with IC50  = 0.67 µM compared to Roscovitine (IC50  = 0.64 µM). The most active candidates arrested the cell cycle at G1, S phases, or both, leading to cell death and inducing apoptosis against CNS (SNB-19), melanoma (MDA-MB-435), and non-small cell lung cancer (HOP-62) cell lines. The molecular docking study verified the resulting outcomes for the most active candidates in the CDK2-binding pocket. Finally, physicochemical, and pharmacokinetic properties deduced that compounds 4c, 6a, 6b, 6d, and 6g displayed significant drug-likeness properties. According to the obtained results, the newly targeted compounds are regarded as promising scaffolds for the continued development of novel CDK2 inhibitors.

Design, synthesis, and biological evaluation of N-(pyridin-3-yl)pyrimidin-4-amine analogues as novel cyclin-dependent kinase 2 inhibitors for cancer therapy

The discovery and development of CDK2 inhibitors has currently been validated as a hot topic in cancer therapy. Herein, a series of novel N-(pyridin-3-yl)pyrimidin-4-amine derivatives were designed and synthesized as potent CDK2 inhibitors. Among them, the most promising compound 7l presented a broad antiproliferative efficacy toward diverse cancer cells MV4-11, HT-29, MCF-7, and HeLa with IC50 values of 0.83, 2.12, 3.12, and 8.61 μM, respectively, which were comparable to that of Palbociclib and AZD5438. Interestingly, these compounds were less toxic on normal embryonic kidney cells HEK293 with high selectivity index. Further mechanistic studies indicated 7l caused cell cycle arrest and apoptosis on HeLa cells in a concentration-dependent manner. Moreover, 7l manifested potent and similar CDK2/cyclin A2 nhibitory activity to AZD5438 with an IC50 of 64.42 nM. These findings revealed that 7l could serve as ahighly promisingscaffoldfor CDK2 inhibitors as potential anticancer agents and functional probes.