HER2 Kinase-Targeted Breast Cancer Therapy: Design, Synthesis, and In Vitro and In Vivo Evaluation of Novel Lapatinib Congeners as Selective and Potent HER2 Inhibitors with Favorable Metabolic Stability

Design, synthesis, and evaluation of new benzimidazole‏ ‏‎thiourea ‎derivatives as antitumor agents

Novel benzimidazole thiourea derivatives were designed and synthesized based on sorafenib as a lead compound. The benzimidazole moiety was traded by the pyridine ring to enhance the hydrophobic interaction and retain hydrogen bonding in the hinge region, while lipophilic moieties with different bulkiness were employed in the deep hydrophobic pocket for better hydrophobic interactions. Thiourea as a urea bioisostere was also utilized. Substantial activity was demonstrated against a leukemia subpanel in an in vitro antitumor screening at the NCI. In the single-dose assay, compounds 7i, 7j, and 7l had a GI%) higher than sorafenib against most leukemia cell lines (GI% = 86.2%-137.1%), while in the five-dose assay, compound 7l outperformed sorafenib against the HL-60(TB) and SR leukemia cell lines in terms of GI50 , TGI, and LC50 . Compound 7l also caused cycle arrest at the G0-G1 and S phases in the HL-60(TB) leukemia cell line and induced apoptosis via elevating the Bax/Bcl-2 ratio and increasing caspases 3, 7, and 9 by 5.1-, 3.2-, and 5.2-fold, respectively. Compounds 7i, 7j, and 7l also inhibited the vascular ‎endothelial growth factor receptor-2 (VEGFR-2), B-Raf(V600E) , and platelet-derived growth factor receptor ‎beta (PDGFR-β) enzymes with an IC50 range of 0.063-0.44 μM. COMPARE analysis and a molecular docking study were also performed to predict the possible mechanism of action and binding mode, respectively.

Quinazolin-4-one/3-cyanopyridin-2-one Hybrids as Dual Inhibitors of EGFR and BRAFV600E: Design, Synthesis, and Antiproliferative Activity

A novel series of hybrid compounds comprising quinazolin-4-one and 3-cyanopyridin-2-one structures has been developed, with dual inhibitory actions on both EGFR and BRAFV600E. These hybrid compounds were tested in vitro against four different cancer cell lines. Compounds 8, 9, 18, and 19 inhibited cell proliferation significantly in the four cancer cells, with GI50 values ranging from 1.20 to 1.80 µM when compared to Doxorubicin (GI50 = 1.10 µM). Within this group of hybrids, compounds 18 and 19 exhibited substantial inhibition of EGFR and BRAFV600E. Molecular docking investigations provided confirmation that compounds 18 and 19 possess the capability to inhibit EGFR and BRAFV600E. Moreover, computational ADMET prediction indicated that most of the newly synthesized hybrids have low toxicity and minimal side effects.

Small-molecule inhibitors of kinases in breast cancer therapy: recent advances, opportunities, and challenges

Breast cancer is the most common malignancy in women worldwide and despite significant advancements in detection, treatment, and management of cancer, it is still the leading cause of malignancy related deaths in women. Understanding the fundamental biology of breast cancer and creating fresh diagnostic and therapeutic strategies have gained renewed focus in recent studies. In the onset and spread of breast cancer, a group of enzymes known as kinases are extremely important. Small-molecule kinase inhibitors have become a promising class of medications for the treatment of breast cancer owing to their capacity to specifically target kinases involved in the growth and progression of cancer. The creation of targeted treatments that block these kinases and the signalling pathways that they activate has completely changed how breast cancer is treated. Many of these targeted treatments have been approved for the treatment of breast cancer as clinical trials have demonstrated their great efficacy. CDK4/6 inhibitors, like palbociclib, abemaciclib, and ribociclib, EGFR inhibitors such as gefitinib and erlotinib and HER2-targeting small-molecule kinases like neratinib and tucatinib are some examples that have shown potential in treating breast cancer. Yet, there are still difficulties in the development of targeted medicines for breast cancer, such as figuring out which patient subgroups may benefit from these therapies and dealing with drug resistance problems. Notwithstanding these difficulties, kinase-targeted treatments for breast cancer still have a lot of potential. The development of tailored medicines will continue to be fuelled by the identification of novel targets and biomarkers for breast cancer as a result of advancements in genomic and proteomic technology.

Design, Synthesis, Antiproliferative Actions, and DFT Studies of New Bis-Pyrazoline Derivatives as Dual EGFR/BRAFV600E Inhibitors

Some new Bis-pyrazoline hybrids 8-17 with dual EGFR and BRAFV600E inhibitors have been developed. The target compounds were synthesized and tested in vitro against four cancer cell lines. Compounds 12, 15, and 17 demonstrated strong antiproliferative activity with GI50 values of 1.05 µM, 1.50 µM, and 1.20 µM, respectively. Hybrids showed dual inhibition of EGFR and BRAFV600E. Compounds 12, 15, and 17 inhibited EGFR-like erlotinib and exhibited promising anticancer activity. Compound 12 is the most potent inhibitor of cancer cell proliferation and BRAFV600E. Compounds 12 and 17 induced apoptosis by increasing caspase 3, 8, and Bax levels, and resulted in the downregulation of the antiapoptotic Bcl2. The molecular docking studies verified that compounds 12, 15, and 17 have the potential to be dual EGFR/BRAFV600E inhibitors. Additionally, in silico ADMET prediction revealed that most synthesized bis-pyrazoline hybrids have low toxicity and adverse effects. DFT studies for the two most active compounds, 12 and 15, were also carried out. The values of the HOMO and LUMO energies, as well as softness and hardness, were computationally investigated using the DFT method. These findings agreed well with those of the in vitro research and molecular docking study.

Discovery of fluorinated 2‑Styryl 4(3H)-quinazolinone as potential therapeutic hit for oral cancer

Oral squamous cell carcinoma (OSCC) is the most common malignant epithelial neoplasm, affects the mouth and throat, and accounts for 90 % of oral cancers. Considering the associated morbidity with neck dissections and the limitation of existing therapeutic agents, the discovery and development of new anticancer drugs/drug candidates for oral cancer treatment are of the utmost need. In this context, reported here is the identification of fluorinated 2‑styryl 4(3H)-quinazolinone as a promising hit for oral cancer. Preliminary studies indicate that the compound blocks the transition of G1 to S phase, thereby leading to arrest in the G1/S phase. Subsequent RNA-seq analysis revealed that the compound induces the activation of molecular pathways involved in apoptosis (such as TNF signalling through NF-κB, p53 pathways) and cell differentiation and suppresses the pathways of cellular growth and development (such as KRAS signaling) in CAL-27 cancer cells. It is noted that identified hit complies with a favorable range of ADME properties as per the computational analysis.

Privileged Scaffolds in Drug Discovery against Human Epidermal Growth Factor Receptor 2 for Cancer Treatment

HER2 is the membrane receptor tyrosine kinase showing overexpression in several human malignancies, particularly breast cancer. HER2 overexpression causes the activation of Ras- MAPK and PI3K/Akt/ NF-κB cellular signal transduction pathways that lead to cancer development and progression. HER2 is, therefore, presumed as one of the key targets for the development of tumor-specific therapies. Several preclinical have been developed that function by inhibiting the HER2 tyrosine kinase activity through the prevention of the dimerization process. Most HER2 inhibitors act as ATP competitors and prevent the process of phosphorylation, and abort the cell cycle progression and proliferation. In this review, the clinical drug candidates and potent pre-clinical newly developed molecules are described, and the core chemical scaffolds typically responsible for anti-HER2 activity are deciphered. In addition, the monoclonal antibodies that are either used in monotherapy or in combination therapy against HER2-positive cancer are briefly described. The identified key moieties in this study could result in the discovery of more effective HER2-targeted anticancer drug molecules and circumvent the development of resistance by HER2-specific chemotherapeutics in the future.

Design and synthesis of some new 6-bromo-2-(pyridin-3-yl)-4-substituted quinazolines as multi tyrosine kinase inhibitors

The present study involves design and synthesis of five series of 6-bromo-2-(pyridin-3-yl)-4-substituted quinazolines 9a-l, 11a-e, 13a-c, 14a-f and 15a-e. Candidates 9a-l and 11a-e were evaluated for their EGFR and HER2 inhibitory activity compared to Lapatinib. Compounds 9b, 9d, 9f, 11b and 11c were further screened for their in vitro cytotoxicity against two human breast cancer cell lines: AU-565 and MDA-MB-231 in addition to normal breast cell line MCF10A. Compound 9d revealed a remarkable cytotoxic efficacy against AU-565 cell line (IC₅₀ = 1.54 µM) relative to Lapatinib (IC₅₀ = 0.48 µM), whereas compounds 9d and 11c showed a superior cytotoxicity towards MDA-MB-231 (IC₅₀ = 2.67 and 1.75 µM, respectively) in comparison to Lapatinib (IC₅₀ = 9.29 µM). Moreover, compounds 13a-c, 13a-c, 14a-f and 15a-e were tested for their VEGFR-2 inhibitory activity compared to Sorafenib. Compounds 13a, 14c and 14e exhibited remarkable inhibition (IC₅₀ = 79.80, 50.22 and 78.02 nM, respectively) relative to Sorafenib (IC₅₀ = 51.87 nM). In vitro cytotoxicity of these compounds against HepG2, HCT-116 and normal cell (WISH) revealed a superior cytotoxicity against HepG2, HCT-116 especially 13a (IC₅₀ = 17.51 and 5.56 µM, respectively) and 14c (IC₅₀ = 10.40 and 3.37 µM, respectively) compared to Sorafenib (IC₅₀ = 19.33 and 6.82 µM, respectively). Compounds 9d, 11c and 14c were subjected to cell cycle analysis and apoptotic assay. Molecular docking and ADME prediction studies were fulfilled to illustrate the interaction of the potent derivatives with the hot spots of the active site of EGFR, HER2 and VEGFR-2 along with prediction of their pharmacokinetic and physicochemical properties.

Discovery of SPH5030, a Selective, Potent, and Irreversible Tyrosine Kinase Inhibitor for HER2-Amplified and HER2-Mutant Cancer Treatment

Small-molecule irreversible tyrosine kinase inhibitors as high potent agents have led to improvements in disease-free and overall survival in patients with HER2-amplified cancer. The approved irreversible HER2 inhibitors, neratinib and pyrotinib, both lack HER2 selectivity, leading to off-target adverse events in patients. The development of HER2 mutation during treatment also hampers the progress of the treatment. We used a molecular hybridization strategy for structural optimizations, in conjunction with in vitro and in vivo drug-like property screening, to obtain a clinical candidate SPH5030. Overall, SPH5030 showed excellent activities against four frequent kinds of HER2 mutants and high relative HER2 selectivity compared with neratinib and pyrotinib, good pharmacokinetic characteristics with desirable bioavailabilities, and significant in vivo antitumor efficacy in xenograft mouse models, especially in a HER2 mutation A775_G776insYVMA xenograft mouse model with its potency much higher than those of neratinib and pyrotinib.

Synthesis and Evaluation of Novel 1,2,6-Thiadiazinone Kinase Inhibitors as Potent Inhibitors of Solid Tumors

A focused series of substituted 4H-1,2,6-thiadiazin-4-ones was designed and synthesized to probe the anti-cancer properties of this scaffold. Insights from previous kinase inhibitor programs were used to carefully select several different substitution patterns. Compounds were tested on bladder, prostate, pancreatic, breast, chordoma, and lung cancer cell lines with an additional skin fibroblast cell line as a toxicity control. This resulted in the identification of several low single digit micro molar compounds with promising therapeutic windows, particularly for bladder and prostate cancer. A number of key structural features of the 4H-1,2,6-thiadiazin-4-one scaffold are discussed that show promising scope for future improvement.

Conjugates Derived from Lapatinib Derivatives with Cancer Cell Stemness Inhibitors Effectively Reversed Drug Resistance in Triple-Negative Breast Cancer

Increasing evidence indicates that the cancer stem cell (CSC) subpopulation contributes to the therapeutic resistance and metastasis of tumors, leading to patient recurrence and death. Herein, we designed and synthesized several compounds by conjugating lapatinib derivatives with different CSC inhibitors to treat with lapatinib-induced MDA-MB-231 drug-resistant cells. In vitro biological studies indicated that 3a showed strong cytotoxicity and EGFR enzyme inhibitory activity and effectively reversed lapatinib-mediated resistance of MDA-MB-231 cells via inhibiting triple-negative breast cancer (TNBC) cell stemness and the AKT/ERK signaling pathway. In addition, 3a was capable of strongly suppressing the invasion and migration of TNBC cells by inhibiting the Wnt/β-catenin signaling pathway and MMP-2 and MMP-9 protein expression. In vivo tumorigenicity tests showed that 3a could inhibit the occurrence of TNBC by inhibiting BCSCs, proving 3a is a potential EGFR and CSC dual inhibitor for TNBC treatment.

Discovery of penipanoid C-inspired 2-(3,4,5-trimethoxybenzoyl)quinazolin-4(3H)-one derivatives as potential anticancer agents by inhibiting cell proliferation and inducing apoptosis in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is the most common form of liver cancer and the fourth leading cause of cancer-related death worldwide. First-line drugs such as sorafenib provide only a modest benefit to HCC patients. In this study, the gram-scale synthesis of 2-benzoylquinazolin-4(3H)-one skeleton was achieved successfully via the I₂/DMSO catalytic system. A series of penipanoid C-inspired 2-(3,4,5-trimethoxybenzoyl)quinazolin-4(3H)-one derivatives was synthesized and evaluated for their cytotoxic activities against four cancer cell lines, HepG2, Bel-7402, A549, and U251. Among these compounds, 4a was the most effective one with IC₅₀ values of 1.22 μM and 1.71 μM against HepG2 and Bel-7402 cells, respectively. Mechanistic studies showed that 4a inhibited hepatocellular carcinoma cell proliferation via arresting cell cycle. Additionally, 4a induced HepG2 cells apoptosis by inducing reactive oxygen species production and elevating the expression of apoptosis-related proteins. More importantly, 4a displayed significant in vivo anticancer effects in the HepG2 xenograft models. This suggests that 4a is a promising lead compound with the potential to be developed as a chemotherapy agent for hepatocellular carcinoma.

Design and evaluation of 1,2,3-dithiazoles and fused 1,2,4-dithiazines as anti-cancer agents

Heteroatom rich 1,2,3-dithiazoles are relatively underexplored in medicinal chemistry. We now report screening data on a series of structurally diverse 1,2,3-dithiazoles and electronically related 1,2,4-dithiazines with the aim of identifying interesting starting points for potential future optimisation. The 1,2,3-dithiazoles, were obtained via a number of different syntheses and screened on a series of cancer cell lines. These included breast, bladder, prostate, pancreatic, chordoma and lung cancer cell lines with an additional skin fibroblast cell line as a toxicity control. Several low single digit micromolar compounds with promising therapeutic windows were identified for breast, bladder and prostate cancer. Furthermore, key structural features of 1,2,3-dithiazoles are discussed, that show encouraging scope for future refinement.