Design, synthesis, X-ray crystal structures, anticancer, DNA binding, and molecular modelling studies of pyrazole-pyrazoline hybrid derivatives.

We have designed and synthesized three pyrazole analogs (4, 5a, 5b), pyrazole-based chalcones (6a-6d) and (8a-8h), and N-formyl/acetyl 1,3,5-trisubstituted pyrazoline analogs (7a-7d), (9a-9d). FT-IR, 1H, 13C NMR, and mass spectrometry techniques were used to describe the structures of all the synthesized analogs. The single crystal X-ray method was used to identify the molecular structure of derivatives 4 and 5a. All synthesized analogs were screened by MTT assay on two cancer cell lines, the human lung cancer cell line (A549) and cervical cancer cell line (HeLa). Among all compounds, analog 9d demonstrates significant anticancer activity against HeLa (IC50 = 23.6 µM) and A549 (IC50 = 37.59 µM). The non-interactive interaction of active compound (9d) with Calf thymus DNA (Ct-DNA) has been investigated through various methods, such as UV-vis absorption, emission, cyclic voltammetry and circular dichroism. The DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical has been used to measure the antioxidant capacity of the pyrazoline derivative (9d). The outcomes showed that active analog has significant antioxidant activity. In addition, MD simulation of the EGFR tyrosine kinase protein-ligand complex was performed at a time scale of 100 ns. The MMGBSA data of ligand-protein complex are showed stable interactions up to 100 ns.

Unraveling molecular mechanisms of head and neck cancer.

Malignancies that develop from mucosal epithelium of the upper aerodigestive tract are known as head and neck squamous cell carcinomas (HNSCC). Heterogeneity, late stage diagnosis and high recurrence rate are big hurdles in head and neck treatment regimen. Presently, the biomarkers available for diagnosis and prognosis of HNSCC are based on smoking as the major risk habit. This review shed light on the differential environment of HNSCC in smokeless tobacco consuming Indian patients. Frequent mutation in genes involved in DNA repair pathway (p53), cell proliferation (PIK3CA, HRAS) and cell death (CASP8, FADD) are common in western population. On the contrary, the genes involved in metastasis (MMPs, YAP1), lymphocyte proliferation (TNFRSF4, CD80), cell-cell adhesion (DCC, EDNRB), miRNA processing (DROSHA) and inflammatory responses (TLR9, IL-9) are mutated in Indian HNSCC patients. Gene ontology enrichment analysis highlighted that responses to chemical stimulus, immune pathways and stress pathways are highly enriched in Indian patients.

Prochlorperazine enhances radiosensitivity of non-small cell lung carcinoma by stabilizing GDP-bound mutant KRAS conformation.

Lung cancer is considered as leading cancer with the highest mortality. The KRAS-oncogenic mutations are dominant in lung carcinoma leading to poor prognosis and radioresistance, which is a major impediment to radiotherapy. Thus, KRAS mutant inhibitors that synergistically sensitize tumours to radiation are urgently needed. In pursuance of the search for a novel radiosensitizer, high-throughput screening of FDA-approved drugs was performed at active site of K-Ras. Prochlorperazine (PCZ), an antipsychotic drug, showed good binding affinity with KRAS-mutant proteins. PCZ binds to the GTP-binding pocket of KRAS-mutant protein and inhibits its constitutive activation by stabilizing the GDP-bound conformation of K-Ras mutants by 9 kcal/mol compared to WT. PCZ alongwith radiation decreased the clonogenic survival of KRAS-mutant NSCLC but not KRAS-WT cells. The combination treatment activates p-ATM, p53, and p21 proteins, leading to cell cycle arrest. PCZ with increasing radiation caused a linear increase in γH2AX foci, suggesting enhanced DSBs-associated apoptosis in radioresistant A549 cells. Pharmacokinetics study showed Cmax = 526 ng/ml at 30min, 4.6h half-life in plasma, and highest accumulation in tumours. PCZ and 10Gy irradiation synergistically radiosensitize mice xenografts via downregulation of Ras/Raf/MEK/ERK pathway. Our efforts have led to the discovery of PCZ as a lead compound. In preclinical analyses, treatment with PCZ alone and in combination with radiation led to regression of KRAS-G12S tumours.