Pancreatic cancer is lethal due to poor prognosis with 5-year survival rate lesser than 5 %. Gemcitabine is currently used to treat pancreatic cancer and development of chemoresistance is a major ...obstacle to overcome pancreatic cancer. Nicotine is a known inducer of drug resistance in pancreatic tumor micro-environment. Present study evaluates chemoresistance triggered by nicotine while treating with gemcitabine and chemosensitization using Embelin. Embelin is a naturally occurring benzoquinone from Embelia ribes possessing therapeutic potency. To develop nicotine-induced chemo-resistance, pancreatic cancer cells PANC-1 and MIA PaCa-2 were continuously treated with nicotine followed by exposure to gemcitabine. Gemcitabine sensitivity assay and immunoblotting was performed to assess the chemo-resistance. Antiproliferative assays such as migration assay, clonogenic assay, Mitochondrial Membrane Potential (MMP) assay, dual staining assay, comet assay, Reactive Oxygen Species (ROS) assay, cell cycle analysis and immunoblotting assays were performed to witness the protein expression involved in chemoresistance and chemosensitization. Epithelial to mesenchymal transition was observed in nicotine induced chemoresistant cells. Gemcitabine sensitivity assay revealed that relative resistance was increased to 6.26 (p < 0.0001) and 6.45 (p < 0.0001) folds in resistant PANC-1 and MIA PaCa-2 compared to parental cells. Protein expression studies confirmed resistance markers like hENT1 and dCK were downregulated with subsequent increase in RRM1 expression in resistant cells. Embelin considerably decreased the cell viability with an IC50 value of 4.03 ± 0.08 μM in resistant PANC-1 and 2.11 ± 0.04 μM in resistant MIA PaCa-2. Cell cycle analysis showed Embelin treatment caused cell cycle arrest at S phase in resistant PANC-1 cells; in resistant MIA PaCa-2 cells there was an escalation in the Sub G1. Embelin upregulated Bax, γH2AX, p53, ERK1/2 and hENT1 expression with concomitant down regulation of Bcl-2 and RRM1. Bioactive molecule embelin, its combination with gemcitabine could provide new vistas to overcome chemo resistance in pancreatic cancer.
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•The study deciphers effects of Nicotine treatment on gemcitabine resistance in pancreatic cancer.•Chemoresistant pancreatic cancer cells showed modulation of gemcitabine resistant markers.•Embelin sensitizes the resistant cells through hENT1/RRM1 signalling.
•The 3-methoxyphenyl nicotinamide scaffolds were synthesised via Suzuki Miyaura coupling reaction.•The synthesised compounds were purified by chromatographically and their confirmation has been ...identified via spectroscopic techniques (1H NMR, 13C NMR and HRMS).•2-picolylamine and 2‑chloro-4-methylbenzene based 5d and 5f were revealed to be potent against MIA PaCa-2 cell line with IC50 values of 26.28±1.21µM and 18.61±0.20µM, respectively.•Compounds 5d and 5f exhibited reduced cytotoxic activity against the normal cell line (HEK 293), with IC50 values of 82.6µM and 138.07µM.
Pancreatic cancer is one of the most fatal malignancies with low survival rate and spreads asymptomatically due to the intensive involvement and expression of PARP1 protein. Nicotinamide is recognised as an efficient ring system in the treatment of pancreatic cancer because of its uses in both cellular and biological processes. In this investigation, 3-methoxyphenyl nicotinamide derivatives were synthesised utilizing a palladium-catalysed Suzuki-Miyaura coupling, and their confirmation has been identified by spectroscopic techniques (HRMS, 1H NMR & 13C NMR). The confirmed compounds (5a-f) were introduced to in-vitro cytotoxic studies using the MTT assay, which demonstrated that 5d and 5f were potent against MIA PaCa-2 cell line with IC50 values of 26±1.21µM and 18.61±0.20µM. The compounds 5d and 5f were also examined against HEK 293 cells, which exhibited a diminished antiproliferative effect with an IC50 values of 82.6µM and 138.07µM, respectively. Consequently, 5d and 5f were found to be safer with reduced antiproliferative effect. The MTT assay results were validated by the molecular docking and ADMET studies, which revealed the binding affinities of compounds 5d and 5f are -9.1 and -9.4 Kcal/mol. Overall, the designed and synthesised conjugates 5d and 5f demonstrated a viable lead for the investigation of new chemotherapeutic drugs against pancreatic cancer in this study.
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•The thieophine-3-carbonitrile based compounds were designed and synthesized.•N-methyl piperazine based 5b was the most potent compound with micromolar IC50 value on Mia PaCa-2 cell ...line.•5b signifies that, it’s less noxious than positive control when treated against a normal cell line L-929.•5b improved Gefitinib's anti-growth impact against Mia PaCa-2 cell line with 2.04 time’s greater selectivity.•In-vitro enzyme inhibition studies were carried.
A series of new thiophene analogues with acarbonitrile-basedmoiety were designed and synthesized via structural optimization. The conjugates were assessed for their in-vitro cytotoxic activity against a human pancreatic cancer cell line (Mia PaCa-2) and among them compound 5b showed IC50 value of 13.37 ± 2.37 μM. The compounds 5b (20 µM & 25 µM) and 7c (30 & 35 µM) also showed reduced clonogenicity, enhanced ROS and decreased mitochondrial membrane potential in Mia PaCa-2 cells. Treatment with these compounds also increased apoptotic population as evident with the double staining assay. Among the evaluated series, compounds 5b, 5g, 7c, and 9a attained a greater inhibitory potency than first generation’s reversible EGFR inhibitor, Gefitinib. EGFR2 enzyme inhibitory studies revealed that 5b efficiently and arbitrarily suppressed the development of EGFR2 dependent cells and inhibited the enzymatic activity with an IC50 value of 0.68 µM; interestingly, the most effective molecule 5b with N-methyl piperazine substitution, has 1.29-fold greater potency than well-known EGFR inhibitor Gefitinib and increased Gefitinib's anti-growth impact with 2.04 folds greater against Mia PaCa-2. The in-vitro studies were validated with in-silico docking studies wherein compounds 5b and 7c exhibited binding energies of −8.2 and −7.4 Kcal/mol respectively. The present study reveals that tetrahydrobenzothiophene based analogues could be a promising lead for the evolution of potent chemo preventives over pancreatic cancer.
