Novel NO-TZDs and trimethoxychalcone-based DHPMs: design, synthesis, and biological evaluation as potential VEGFR-2 inhibitors.

Novel series of nitric oxide-releasing thiazolidine-2,4-diones (NO-TZD-3a-d,5,6) and 3,4,5-trimethoxychalcone-based multifunctional 1,4-dihydropyrimidines (CDHPM-10a-g) have been designed and synthesised as potent broad-spectrum anticancer agents with potential VEGFR-2 inhibition. The designed analogs were evaluated for their anticancer activities towards a full panel of NCI-60 tumour cell lines and CDHPM-10a-g emerged mean %inhibitions ranging from 76.40 to 147.69%. Among them, CDHPM-10e and CDHPM-10f demonstrated the highest MGI% of 147.69 and 140.24%, respectively. Compounds CDHPM-10a,b,d-f showed higher mean %inhibitory activity than the reference drug sorafenib (MGI% = 105.46%). Superiorly, the hybrid CDHPM-10e displayed the highest potencies towards all the herein tested subpanels of nine types of cancer with MGI50 of 1.83 µM. Also, it revealed potent cytostatic single-digit micromolar activity towards the herein examined cancer cell lines. The designed compounds CDHPM-10a-g were exposed as potent non-selective broad-spectrum anticancer agents over all NCI subpanels with an SI range of 0.66-1.97. In addition, the target analog CDHPM-10e revealed potency towards VEGFR-2 kinase comparable to that of sorafenib with a sub-micromolar IC50 value of 0.11 µM. Also, CDHPM-10e could effectively induce Sub-G1-phase arrest and prompt apoptosis via caspase and p53-dependent mechanisms. Furthermore, CDHPM-10e revealed significant anti-metastatic activity as detected by wound healing assay. The modelling study implies that CDHPM-10e overlaid well with sorafenib and formed a strong H-bond in the DFG binding domain. The ADMET studies hinted out that CDHPM-10e met Pfizer's drug-likeness criteria. The presented novel potent anticancer agent merits further devotion as a new lead product in developing more chalcone-based VEGFR-2 inhibitors.

Novel EGFR-MAPK kinase and ABC transporter inhibitors for HepG2 resistant to Erlotinib.

Hepatocellular carcinoma (HCC) is the third-leading cause of cancer death in the world, with outlook for most patients having a 5-year survivability of less than 5%. In a previous study from our laboratory, novel estrone inspired analogs act as epidermal growth factor receptor (EGFR) inhibitors in HepG2 cells. This study focuses on the effect of these analogs on an HCC cell line resistance to Erlotinib. Lead compounds MMA132 and MMA102 showed 13 and 20 µM IC50 values, respectively against HepG2-R resistant to Erlotinib. These compounds showed cell cycle arrest of the G2 phase up to 54%, and inhibited cell migration of HepG2-R cells up to 48 h. Western blot analysis revealed that MMA132 reduced total EGFR content after 48 h, while MMA102 inhibited MEK kinase by 84% after 48 h. Western blot analysis also revealed that multidrug resistance protein 2 (MRP2) is overexpressed in HepG2-R, suggesting that ABC transporters play a likely cause in drug resistance. MMA102 showed significant inhibition of both P-glycoprotein (83%) and ABCG2 (53%), two additional ABC transporters. Additionally, MMA102 and MMA132 were used in a combination therapy with MK571(MRP1/2 inhibitor) and produced IC50 values of 18 and 10 µM, respectively, better than either MMA102/132 or MK571 alone. To validate our findings, we conducted molecular dynamic simulations with MMA102 and MMA132 in MEK, P-glycoprotein, MRP1, and MRP2. Results coincided with biological findings in which MMA102 orientation is favored in both MEK and P-glycoprotein pockets, whereas MMA132 likely binds with MRP2, as likely suggested by the combinatorial study.

Cucurbitacins inspired organic synthesis: Potential dual inhibitors targeting EGFR - MAPK pathway.

Natural products have been known as a fundamental source for drug discovery leading to the evolution of Biological Oriented Organic Synthesis (BIOS) approach to assemble natural product mimics. Herein, a series of Cucurbitacin inspired estrone analogs was assembled to generate 18 novel synthesized analogs via installation of double bond across C-16/C-17 positions of estrone scaffold and diastereomeric separation of (R) and (S) at C-20. This was followed by biological screening against HEPG-2 cell lines to exhibit anti-proliferative activity ranging from IC50 0.70-32 µM. Two analogs (MMA-102 and MMA-132) were chosen for further biological elucidation to exhibit dual inhibitory mechanism against the phosphorylating pathways of EGFR and MAPK (RAS/RAF/MEK/ERK) pathways. Both of MMA-102 and MMA-132 showed cell cycle arrest with elevated levels of apoptotic parameters. Molecular modeling simulations suggested the potential of MMA-102 and MMA-132 to compete with ATP within the catalytic binding domains of EGFR and MAPK pathway.

Novel series of 6-(2-substitutedacetamido)-4-anilinoquinazolines as EGFR-ERK signal transduction inhibitors in MCF-7 breast cancer cells.

Epidermal growth factor receptor (EGFR) signaling pathway has been previously investigated for its significant role in the progression of different types of malignant tumors, where development of small molecules targeting EGFR is well known strategy for design of antitumor agents. Herein, we report the design and synthesis of two series of 6-(2-substitutedacetamido)-4-anilinoquinazolines (6a-x and 13a-d) as EGFR inhibitors. All the newly synthesized quinazoline derivatives were in vitro evaluated for their anti-proliferative activity towards MCF-7 (Breast Cancer) and HepG2 (Hepatocellular carcinoma) cell lines. In particular, compound 6n showed significant inhibitory activity against MCF-7 and HepG2 cell lines (IC50 = 3 and 16 µM, respectively), compared to that of Erlotinib (IC50 = 20 and 25 µM, respectively). Western blotting of 6n at MCF-7 cell line revealed the dual inhibitory activity of 6n towards diminishing the phosphorylated levels for EGFR and ERK. Also, ELISA assay confirmed the anti-EGFR activity of compound 6n (IC50 = 0.037 µM). Finally, a molecular docking study showed the potential binding mode of 6n within the ATP catalytic binding site of EGFR, exhibiting similar binding mode to EGFR inhibitor Erlotinib.

Design and synthesis of pyrazolo[3,4-d]pyrimidines: Nitric oxide releasing compounds targeting hepatocellular carcinoma.

A new series of pyrazolo[3,4-d]pyrimidines tethered with nitric oxide (NO) producing functionality was designed and synthesized. Sulforhodamine B (SRB) protein assay revealed that NO releasing moiety in the synthesized compounds significantly decreased the cell growth more than the des-NO analogues. Compounds 7C and 7G possessing N-para-substituted phenyl group, released the highest NO concentration of 4.6% and 4.7% respectively. Anti-proliferative activity of synthesized compounds on HepG2 cell line identified compounds 7h, 7p, 14a and 14b as the most cytotoxic compounds in the series of IC50=3, 5, 3 and 5µM, respectively, compared to erlotinib as a reference drug (IC50=25µM). Flow cytometry studies revealed that 7h arrested the cells in G0/G1 phase of cell cycle while 7p arrested the cells in S phase. Moreover, docking study of the synthesized compounds on EGFR (PDB code: 1M17) and cytotoxicity study indicated that N-1 phenyl para substitution, pyrazole C-3 alkyl substitution and tethering the nitrate moiety through butyl group had a significant impact on the activity.