Synthesis and biological activity of 11-Oxygenated and heterocyclic estrone analogs in pancreatic cancer monolayers and 3D spheroids.

Pancreatic Ductal Adenocarcinoma (PDAC), representing over 90 % of pancreatic cancer diagnoses, is an aggressive disease with survivability among the worst of all cancers due to its difficulty in detection and its high metastatic properties. Current therapies for PDAC show limited success at extending life expectancies, primarily due to cancer resistance and lack of patient-specific targeted therapies. This work highlights the design and evaluation of estrone-derived analogs with both heterocyclic side-chain functionality and 11-oxygenated functionality for use in pancreatic cancer. First-round heterocyclic analogs show preliminary promise in AsPC-1 and Panc-1 cell lines, with IC50 values as low as 10.16 ± 0.83 µM. Their success, coupled with design choices from other studies, led to the synthesis of novel 11-hydroxyl and 11-keto estrone analogs that show potent in-vitro toxicity against various pancreatic cancer models. The three most cytotoxic analogs, KA1, KA2, and KA9 demonstrated low micromolar activities in both MTT and CellTiter assays in three pancreatic cancer cell lines: AsPC-1, Panc-1, and BxPC-3, as well as in a co-culture of Panc-1 and pancreatic stellate cells. IC50 values for KA9 (4.17 ± 0.90, 5.28 ± 1.87, and 5.70 ± 0.65 µM respectively) shows consistency in all cell lines tested. KA9 is also able to cause an increase in caspases 3 and 7 activity, key markers for apoptosis, at non-cytotoxic concentrations. Additional work was performed by generating 3D pancreatic cancer spheroids to better modulate the pancreatic tumor microenvironment, and KA9 continued to show the best IC50 values (21.0 and 24.3 µM) in both cell types tested. KA9 was also able to prevent the growth of spheroids whereas the standard chemotherapy, Gemcitabine, could not, suggesting that it may be a potent analog for future development of treatments. Molecular dynamic simulations were also performed to confirm biological findings and uncovered that KA9's preferential binding location is in the active site pocket of key proteins involved in cytotoxicity.

Synthesis and Antitumor Activity of Brominated-Ormeloxifene (Br-ORM) against Cervical Cancer.

Aberrant regulation of ß-catenin signaling is strongly linked with cancer proliferation, invasion, migration, and metastasis, thus, small molecules that can inhibit this pathway might have great clinical significance. Our molecular modeling studies suggest that ormeloxifene (ORM), a triphenylethylene molecule that docks with ß-catenin, and its brominated analogue (Br-ORM) bind more effectively with relatively less energy (-7.6 kcal/mol) to the active site of ß-catenin as compared to parent ORM. Herein, we report the synthesis and characterization of a Br-ORM by NMR and FTIR, as well as its anticancer activity in cervical cancer models. Br-ORM treatment effectively inhibited tumorigenic features (cell proliferation and colony-forming ability, etc.) and induced apoptotic death, as evident by pronounced PARP cleavage. Furthermore, Br-ORM treatment caused cell cycle arrest at the G1-S phase. Mechanistic investigation revealed that Br-ORM targets the key proteins involved in promoting epithelial-mesenchymal transition (EMT), as demonstrated by upregulation of E-cadherin and repression of N-cadherin, Vimentin, Snail, MMP-2, and MMP-9 expression. Br-ORM also represses the expression and nuclear subcellular localization of ß-catenin. Consequently, Br-ORM treatment effectively inhibited tumor growth in an orthotopic cervical cancer xenograft mouse model along with EMT associated changes as compared to vehicle control-treated mice. Altogether, experimental findings suggest that Br-ORM is a novel, promising ß-catenin inhibitor and therefore can be harnessed as a potent anticancer small molecule for cervical cancer treatment.

Deacetylated Sialic Acid Sensitizes Lung and Colon Cancers to Novel Cucurbitacin-Inspired Estrone Epidermal Growth Factor Receptor (EGFR) Inhibitor Analogs.

Cancers utilize sugar residues such as sialic acids (Sia) to improve their ability to survive. Sia presents a variety of functional group alterations, including O-acetylation on the C6 hydroxylated tail. Previously, sialylation has been reported to suppress EGFR activation and increase cancer cell sensitivity to Tyrosine Kinase Inhibitors (TKIs). In this study, we report on the effect of deacetylated Sia on the activity of three novel EGFR-targeting Cucurbitacin-inspired estrone analogs (CIEAs), MMA 294, MMA 321, and MMA 320, in lung and colon cancer cells. Acetylation was modulated by the removal of Sialate O-Acetyltransferase, also known as CAS1 Domain-containing protein (CASD1) gene via CRISPR-Cas9 gene editing. Using a variety of cell-based approaches including MTT cell viability assay, flow cytometry, immunofluorescence assay and in-cell ELISA we observed that deacetylated Sia-expressing knockout cells (1.24-6.49 µM) were highly sensitive to all CIEAs compared with the control cells (8.82-20.97 µM). Apoptosis and varied stage cell cycle arrest (G0/G1 and G2/M) were elucidated as mechanistic modes of action of the CIEAs. Further studies implicated overexpression of CIEAs' cognate protein target, phosphorylated EGFR, in the chemosensitivity of the deacetylated Sia-expressing knockout cells. This observation correlated with significantly decreased levels of key downstream proteins (phosphorylated ERK and mTOR) of the EGFR pathway in knockout cells compared with controls when treated with CIEAs. Collectively, our findings indicate that Sia deacetylation renders lung and colon cancer cells susceptible to EGFR therapeutics and provide insights for future therapeutic interventions.

Antiproliferation and apoptosis studies of estrone pharmacophores in triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer that shows high metastatic capability and poor prognosis. The aggressive behavior of TNBC may involve amplified EGFR expression. Currently, no targeted therapy has been approved for treating TNBC, which urgently needs novel treatment options. In this study, we report that estrone analogs with novel pharmacophores exhibited high potency toward TNBC cells through multiple mechanisms, inhibition of cell proliferation via EGFR receptor, and induction of mitochondrial apoptosis. Molecular docking studies revealed that hit analogs MMA307 and MMA321 were potent against the EGFR receptor (pdb code: 1M17) in silico and were over 10-fold more potent than sorafenib (positive control) when dosed against MDA-MB-468 cells in vitro. MMA307 and MMA321 induced mitochondrial apoptosis as characterized by condensed nuclei with fragmented chromatin, phosphatidylserine flip and modulated expressions of Apaf1, cytochrome c, and caspases 3 and 9. MMA307 and MMA321 inhibited TNBC proliferation through suppression of EGFR and activated EGFR (Y1068) expressions. Similarly, EGFR signaling pathways, RAF/ERK and AKT/mTOR, were inhibited as pARaf, pERK1/2 (characterizes RAF/ERK pathway) and pAKT, pmTOR, p70S6Kα (characterizes AKT/mTOR pathway) were all suppressed. Moreover, MMA307 and MMA321 inhibited TNBC cell growth through downregulation of cyclin D1 expression and arresting TNBC cells in the G1 phase of cell cycle. This study reports for the first time that estrone congeners with novel pharmacophores may be an effective therapy for TNBC. Findings from this research provide a solid foundation for further preclinical and clinical studies in developing estrone derivatives as novel TNBC therapeutics.

Utilizing Estra-1,3,5,16-Tetraene Scaffold: Design and Synthesis of Nitric Oxide Donors as Chemotherapeutic Resistance Combating Agents in Liver Cancer.

A new series of nitric oxide-releasing estra-1,3,5,16-tetraene analogs (NO-∆-16-CIEAs) was designed and synthesized as dual inhibitors for EGFR and MRP2 based on our previous findings on estra-1,3,5-triene analog NO-CIEA 17 against both HepG2 and HepG2-R cell lines. Among the target compounds, 14a (R-isomer) and 14b (S-isomer) displayed potent anti-proliferative activity against both HepG2 and HepG2-R cell lines in comparison to the reference drug erlotinib. Remarkably, compound 14a resulted in a prominent reduction in EGFR phosphorylation at a concentration of 1.20 µM with slight activity on the phosphorylation of MEK1/2 and ERK1/2. It also inhibits MRP2 expression in a dose-dependent manner with 24% inhibition and arrested the cells in the S phase of the cell cycle. Interestingly, compound 14a (estratetraene core) exhibited a twofold increase in anti-proliferative activity against both HepG2 and HepG2-R in comparison with the lead estratriene analog, demonstrating the significance of the designed ∆-16 unsaturation. The results shed a light on compound 14a and support further investigations to combat multidrug resistance in chemotherapy of hepatocellular carcinoma patients.

Estrone analogs as potential inhibitors targeting EGFR-MAPK pathway in non-small-cell lung cancer.

Lung cancer is the deadliest human cancer globally, with non-small-cell lung cancer (NSCLC) being the most frequent type. Epidermal growth factor receptor (EGFR), a central regulator of tumor progression is frequently overexpressed in NSCLC and is a key drug target along with its downstream pathways. Here, we describe the biological evaluation of previously synthesized estrone analogs as potent inhibitors of NCI-H226 cells. Two of the analogs, MMA307 and MM320, significantly inhibited the proliferation of NCI-H226 cells with IC50 doses of 2.88 ± 0.21 and 9.68 ± 0.24 µM, respectively, compared with the positive control and chemotherapy, sorafenib, IC50 of 20.62 ± 1.32 µM. Exposing NCI-H226 cells to IC50 concentration of MMA307 and MMA320 resulted in the downregulation of EGFR and phospho-EGFR expression levels, and suppression of activated MAPK-ERK1/2 signaling proteins; phospho-B-Raf, phospho-MEK1/2 , and phospho-ERK1/2 . Furthermore, the downregulation of cyclin D1 and concomitant upregulation of phospho-cyclin D1 and p21waf1/cip1 were observed after the compounds' addition to NCI-H226 cells resulting in G1 phase cell cycle arrest. MMA320 but not MMA307 downregulated the expression levels of Dyrk1B, a checkpoint kinase at the G1 -S phase transition of the cell cycle. Additionally, molecular dynamic simulations were performed and found that MMA307 and MMA320 have higher binding affinities than sorafenib in MEK, BRAF, cyclin D1 , and Dyrk1B (dual-specificity tyrosine phosphorylation-regulated kinase 1B). To conclude, the present study is the first to report on the antiproliferative potential of novel estrone analogs and provide evidence that MMA307 and MMA320 are promising novel lead candidates for the development of antilung cancer drugs.

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.

Synthesis of novel pyridine and pyrimidine thioglycoside phosphoramidates for the treatment of COVID-19 and influenza A viruses.

A novel series of pyridine, cytosine, and uracil thioglycoside analogs (4a-i, 9a,b, and 13a,b, respectively) and their corresponding phosphoramidates (6a-I, 10a,b, and 14a,b, respectively) were synthesized and assessed for their antiviral inhibitory activities in a dual-pathogen screening protocol against SARS-CoV-2 and influenza A virus (IAV). MTT cytotoxicity (TC50) and plaque reduction assays were used to explore inhibition and cytotoxicity percentage values for H5N1 influenza virus strain and the half-maximal cytotoxic concentration (CC50) and inhibitory concentration (IC50) for SARS-CoV-2 virus. Most of the tested compounds demonstrated dose-dependent inhibition behavior. Both cytosine thioglycoside phosphoramidates 10a and 10b exhibited the most potent profiles with 83% and 86% inhibition at 0.25 µM concentration against H5N1 and IC50 values of 12.16 µM, 14.9 µM against SARS-CoV-2, respectively. Moreover, compounds 10a and 10b have been shown to have the highest selectivity index (SI) among all the tested compounds against SARS-CoV-2 with 28.2 and 26.9 values, respectively.

Triazole-estradiol analogs: A potential cancer therapeutic targeting ovarian and colorectal cancer.

1,2,3-triazoles have continuously shown effectiveness as biologically active systems towards various cancers, and when used in combination with steroid skeletons as a carrier, which can act as a drug delivery system, allows for a creation of a novel set of analogs that may be useful as a pharmacophore leading to a potential treatment option for cancer. A common molecular target for cancer inhibition is that of the Epidermal Growth Factor Receptor/Mitogen Activated Protein Kinase pathways, as inhibition of these proteins is associated with a decrease in cell viability. Estradiol-Triazole analogs were thus designed using a molecular modeling approach. Thirteen of the high scoring analogs were then synthesized and tested in-vitro on an ovarian cancer cell line (A2780) and colorectal cancer cell line (HT-29). The most active compound, Fz25, shows low micromolar activity in both the ovarian (15.29 ± 2.19 µM) and colorectal lines (15.98 ± 0.39 µM). Mechanism of action studies proved that Fz25 moderately arrests cells in the G1 phase of the cell cycle, specifically inhibiting STAT3 in both cell lines. Additionally, Fz57 shows activity in the colorectal line (24.19 ± 1.37 µM). Inhibition studies in both cell lines show inhibition against various proteins in the EGFR pathway, namely EGFR, STAT3, ERK, and mTOR. To further study their effects as therapeutics, Fz25 and Fz57 were studied against drug efflux proteins, which are associated with drug resistance, and were found to inhibit the ABC transporter P-glycoprotein. We can conclude that these estradiol-triazole analogs provide a key for future studies targeting protein inhibition and drug resistance in cancer.

Sofosbuvir Thio-analogues: Synthesis and Antiviral Evaluation of the First Novel Pyridine- and Pyrimidine-Based Thioglycoside Phosphoramidates.

The synthesis and antiviral screening of the first reported series of pyridine- and pyrimidine-based thioglycoside phosphoramidates are herein reported. They were prepared through two synthetic steps: The first step is via coupling of mercapto-derivatized heterocyclic bases with the appropriate α-bromo per-acetylated sugars. The second one is the hydrolysis of the acetate esters under basic conditions that were consequently conjugated with the phosphoramidating reagent to afford the desired thioglycoside protides. Eight compounds were evaluated for their antiviral activities against different viral cell lines, namely, adenovirus 7, HAV (hepatitis A) HM175, Coxsackievirus B4, and HSV-1 (herpes simplex virus type 1), in addition to the antiviral bioassay against ED-43/SG-Feo (VYG) replicon of HCV (hepatitis C virus) genotype 4a. Both compounds 5b and 11 showed notable antiviral activity against Coxsackie virus B4, reflected from the CC50 values of 17 and 20 µg/100 µL and IC50 values of 4.5 and 6.0 µg/100 µL, respectively. Same two compounds elicited remarkable activities toward herpes simplex virus type 1, represented by CC50 values of 17 and 16 µg/100 µL and IC50 values of 6.3 and 6.6 µg/100 µL, respectively. Combination of 11 with acyclovir elicited a notable synergistic activity in comparison with acyclovir alone, as inferred from herpes simplex polymerase enzyme inhibitory assay values of 2.64 and 4.78 µg/100 mL, respectively. Only compound 11 elicited a remarkable activity against HCV. Potential promising activities of compound 11 have been shown with respect to CC50, IC50, and enzyme assay inhibitory activities.

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.

Cucurbitacin D Reprograms Glucose Metabolic Network in Prostate Cancer.

Prostate cancer (PrCa) metastasis is the major cause of mortality and morbidity among men. Metastatic PrCa cells are typically adopted for aberrant glucose metabolism. Thus, chemophores that reprogram altered glucose metabolic machinery in cancer cells can be useful agent for the repression of PrCa metastasis. Herein, we report that cucurbitacin D (Cuc D) effectively inhibits glucose uptake and lactate production in metastatic PrCa cells via modulating glucose metabolism. This metabolic shift by Cuc D was correlated with decreased expression of GLUT1 by its direct binding as suggested by its proficient molecular docking (binding energy -8.5 kcal/mol). Cuc D treatment also altered the expression of key oncogenic proteins and miR-132 that are known to be involved in glucose metabolism. Cuc D (0.1 to 1 µM) treatment inhibited tumorigenic and metastatic potential of human PrCa cells via inducing apoptosis and cell cycle arrest in G2/M phase. Cuc D treatment also showed inhibition of tumor growth in PrCa xenograft mouse model with concomitant decrease in the expression of GLUT1, PCNA and restoration of miR-132. These results suggest that Cuc D is a novel modulator of glucose metabolism and could be a promising therapeutic modality for the attenuation of PrCa metastasis.

Design, synthesis and biological study of hybrid drug candidates of nitric oxide releasing cucurbitacin-inspired estrone analogs for treatment of hepatocellular carcinoma.

Development of hybrid drug candidates is well known strategy for designing antitumor agents. Herein, a novel class of nitric oxide donating cucurbitacin inspired estrone analogs (NO-CIEAs) were designed and synthesized as multitarget agents. Synthesized analogs were initially evaluated for their anti-hepatocellular carcinoma activities. Among the tested analogs, NO-CIEAs 17 and 20a exhibited more potent activity against HepG2 cells (IC50 = 4.69 and 12.5 µM, respectively) than the reference drug Erlotinib (IC50 = 25 µM). Interestingly, NO-CIEA 17 exerted also a high potent activity against Erlotinib-resistant HepG2 cell line (HepG2-R) (IC50 = 8.21 µM) giving insight about its importance in drug resistance therapy. Intracellular measurements of NO revealed that NO-CIEAs 17 and 20a showed a significant increase in NO production in tumor cells after 1 h of incubation comparable to the reference prodrug JS-K. Flow cytometric analysis showed that both NO-CIEAs 17 and 20a mainly arrested the HepG2 cells in the G0/G1 phase. Also, In-Cell Based ELISA screening showed that NO-CIEA 17 resulted in a potential inhibitory activity towards the EGFR and MAPK (25% and 29% inhibition compared to untreated control cells, respectively). This data suggests the binding ability of NO-CIEA 17 to the EGFR and ERK to be well correlated along with the docking and cellular studies. Also, treatment of HepG2-R cells with NO-CIEA 17 showed a potential reduction of MRP2 expression in a dose dependent manner providing a significant impact on the chemotherapeutic resistance. Overall, the current study provides a potential new approach for the discovery of a novel antitumor agent against HCC.

Novel Mechanistic Insight into the Anticancer Activity of Cucurbitacin D against Pancreatic Cancer (Cuc D Attenuates Pancreatic Cancer).

Pancreatic cancer (PanCa) is one of the leading causes of death from cancer in the United States. The current standard treatment for pancreatic cancer is gemcitabine, but its success is poor due to the emergence of drug resistance. Natural products have been widely investigated as potential candidates in cancer therapies, and cucurbitacin D (Cuc D) has shown excellent anticancer properties in various models. However, there is no report on the therapeutic effect of Cuc D in PanCa. In the present study, we investigated the effects of the Cuc D on PanCa cells in vitro and in vivo. Cuc D inhibited the viability of PanCa cells in a dose and time dependent manner, as evident by MTS assays. Furthermore, Cuc D treatment suppressed the colony formation, arrest cell cycle, and decreased the invasion and migration of PanCa cells. Notably, our findings suggest that mucin 13 (MUC13) is down-regulated upon Cuc D treatment, as demonstrated by Western blot and qPCR analyses. Furthermore, we report that the treatment with Cuc D restores miR-145 expression in PanCa cells/tissues. Cuc D treatment suppresses the proliferation of gemcitabine resistant PanCa cells and inhibits RRM1/2 expression. Treatment with Cuc D effectively inhibited the growth of xenograft tumors. Taken together, Cuc D could be utilized as a novel therapeutic agents for the treatment/sensitization of PanCa.

Isolation of anticancer constituents from Cucumis prophetarum var. prophetarum through bioassay-guided fractionation.

BACKGROUND: Cucumis prophetarum var. prophetarum is used in Saudi folk medicine for treating liver disorders and grows widely between Abha and Khamis Mushait City, Saudi Arabia. METHODS: Bioassay-guided fractionation and purification were used to isolate the main active constituents of Cucumis prophetarum var. prophetarum fruits. These compounds were structurally elucidated using NMR spectroscopy, mass spectral analyses and x-ray crystallography. All fractions, sub-fractions and pure compounds were screened for their anticancer activity against six cancer cell lines. RESULTS: The greatest cytotoxic activity was found to be in the ethyl acetate fraction, resulting in the isolation of five cucurbitacin compounds [E, B, D, F-25 acetate and Hexanorcucurbitacin D]. Among the cucurbitacins that were isolated and tested cucurbitacin B and E showed potent cytotoxicity activities against all six human cancer cell lines. CONCLUSION: Human breast cancer cell lines were found to be the most sensitive to cucurbitacins. Preliminary structure activity relationship (SAR) for cytotoxic activity of Cucurbitacins against human breast cancer cell line MDA-MB-231 has been reported.

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.

Ormeloxifene Suppresses Prostate Tumor Growth and Metastatic Phenotypes via Inhibition of Oncogenic ß-catenin Signaling and EMT Progression.

Ormeloxifene is a clinically approved selective estrogen receptor modulator, which has also shown excellent anticancer activity, thus it can be an ideal repurposing pharmacophore. Herein, we report therapeutic effects of ormeloxifene on prostate cancer and elucidate a novel molecular mechanism of its anticancer activity. Ormeloxifene treatment inhibited epithelial-to-mesenchymal transition (EMT) process as evident by repression of N-cadherin, Slug, Snail, vimentin, MMPs (MMP2 and MMP3), ß-catenin/TCF-4 transcriptional activity, and induced the expression of pGSK3ß. In molecular docking analysis, ormeloxifene showed proficient docking with ß-catenin and GSK3ß. In addition, ormeloxifene induced apoptosis, inhibited growth and metastatic potential of prostate cancer cells and arrested cell cycle in G0-G1 phase via modulation of cell-cycle regulatory proteins (inhibition of Mcl-1, cyclin D1, and CDK4 and induction of p21 and p27). In functional assays, ormeloxifene remarkably reduced tumorigenic, migratory, and invasive potential of prostate cancer cells. In addition, ormeloxifene treatment significantly (P < 0.01) regressed the prostate tumor growth in the xenograft mouse model while administered through intraperitoneal route (250 µg/mouse, three times a week). These molecular effects of ormeloxifene were also observed in excised tumor tissues as shown by immunohistochemistry analysis. Our results, for the first time, demonstrate repurposing potential of ormeloxifene as an anticancer drug for the treatment of advanced stage metastatic prostate cancer through a novel molecular mechanism involving ß-catenin and EMT pathway. Mol Cancer Ther; 16(10); 2267-80. ©2017 AACR.

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.

Biological screening of cucurbitacin inspired estrone analogs targeting mitogen-activated protein kinase (MAPK) pathway.

Assembly of cucurbitacin inspired estrone analogs has been previously synthesized and screened against melanoma cell lines. Further synthetic optimization was executed via installation of Azide polar functional moiety across 23, 24 α, ß-unsaturated ketone side chain using Michael addition reaction. This was followed by biological screening against melanoma cell lines employing MTT assay, in-cell-based ELISA assay, and Western blot analysis to monitor the potential of the synthesized analogs to inhibit the phosphorylated ERK levels. This resulted in evolution of MH-4 possessing IC50 of 3.59 µm with significant decrease in the p-ERK and targeting MAPK pathway.

Design, synthesis, and biological evaluation of steroidal analogs as estrogenic/anti-estrogenic agents.

Series of estrone based analogs were synthetically investigated at positions C-9, C-11, C-16, and C-17 positions, to be biologically evaluated via assessment of cell proliferation, cytotoxicity, and estrogenic/anti-estrogenic activity. LA-7 and LA-10 revealed their potential to exhibit inhibitory estrogenic profile. This was further validated by Estrogen Receptor-α (ER-α) and Estrogen Receptor-ß (ER-ß) competitive binding assays to reveal the high selective affinity of LA-7 towards ER-α at 5.49µM, while LA-10 did not show any binding affinity towards neither ER-α nor ER-ß; suggesting another mechanism for inhibition. This was validated by in silico molecular docking simulations of LA-7 to reveal the optimum binding affinity of LA-7 towards ER-α.