1,2,4-Amino-triazine derivatives as pyruvate dehydrogenase kinase inhibitors: Synthesis and pharmacological evaluation

5-nitro-thiophene-thiosemicarbazone derivative induces cell death, cell cycle arrest, and phospho-kinase shutdown in pancreatic ductal adenocarcinoma cells

INTRODUCTION

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer with limited treatment options. This study explores the potential of novel 5-nitro-thiophene-thiosemicarbazone derivatives as therapeutic agents for PDAC.

METHODS

We evaluated the cytotoxicity of seven derivatives in peripheral blood mononuclear cells (PBMCs) and PDAC cell lines. Promising candidates (PR12 and PR17) were further analyzed for their effects on colony formation, cell cycle progression, and reactive oxygen species (ROS) production. PR17, the most promising derivative, was subjected to additional investigation, including analysis of autophagy-related genes and protein kinase inhibition.

RESULTS

Three derivatives (PR16, PR19, and PR20) displayed cytotoxicity towards PBMCs. PR12 reduced colony formation and G0/G1 cell cycle arrest in PDAC cells. Notably, PR17 exhibited potent activity in MIA PaCa-2 cells, inducing S-phase cell cycle arrest, downregulating autophagy genes, and inhibiting key protein kinases.

CONCLUSION

PR17, a 5-nitro-thiophene-thiosemicarbazone derivative, demonstrates promising antineoplastic activity against PDAC cells by potentially modulating cell cycle progression, autophagy, and protein kinase signaling. Further studies are warranted to elucidate the detailed mechanism of action and explore its efficacy in vivo.

Comparative analysis of leptin and carcinoembryonic antigen-related cell adhesion molecule 1 plasma expression in pancreatic cancer and chronic pancreatitis patients

Compared to the general population, patients with chronic pancreatitis have an up to 12-fold higher risk of developing pancreatic cancer. The aim of our study was the identification of potential proteomic biomarkers to contribute to the detection of pancreatic cancer among patients with chronic pancreatitis. We initially performed a proteomic screening analysis of 105 analytes on plasma pools. To validate this finding, we quantitatively determined leptin concentrations in individual plasma samples using the ELISA technique. Additionally, we explored the plasma expression of CEACAM1, an important regulator of leptin expression in various cancer cells using the same method. The preliminary semi-quantitative proteomic analysis identified leptin as the only protein with substantially higher expression in patients with pancreatic cancer compared to those with chronic pancreatitis. Subsequently, by quantitative ELISA, we determined a higher median leptin concentration in the plasma of patients with pancreatic cancer compared to those with chronic pancreatitis. The statistical significance was maintained regardless of other variables like BMI or gender. Additionally, we explored the plasma expression of CEACAM1, an important regulator of leptin expression in various cancer cells, in order to provide insights into the complex mechanisms underlying pancreatic cancer and chronic pancreatits. CEACAM1 concentrations were higher in the plasma of the patients with pancreatic cancer than in those with chronic pancreatitis. However, we did not find a statistically significant correlation between leptin and CEACAM1 expression variation in the two study groups, with CEACAM1 concentration also dependent on other parameters such as BMI, gender, and serum triglyceride level. In conclusion, leptin seems to be a biomarker that can contribute to differentiate patients with pancreatic cancer from patients with chronic pancreatitis.

Design, synthesis, biological evaluation, and in silico studies of novel pyridopyridine derivatives as anticancer candidates targeting FMS kinase

Design and synthesis of novel 4-carboxamidopyrido[3,2-b]pyridine derivatives as novel rigid analogues of sorafenib are reported herein. The target compounds showed potent antiproliferative activities against a panel of NCI-60 cancer cell lines as well as hepatocellular carcinoma cell line. Compounds 8g and 9f were among the most promising derivatives in terms of effectiveness and safety. Therefore, they were further examined to demonstrate their ability to induce apoptosis and alter cell cycle progression in hepatocellular carcinoma cells. The most potent compounds were tested against a panel of kinases that indicated their selectivity against FMS kinase. Compounds 8g and 8h showed the most potent activities against FMS kinase with IC50 values of 21.5 and 73.9 nM, respectively. The two compounds were also tested in NanoBRET assay to investigate their ability to inhibit FMS kinase in cells (IC50 = 563 nM (8g) and 1347 nM (8h) vs. IC50 = 1654 nM for sorafenib). Furthermore, compounds 8g and 8h possess potent inhibitory activities against macrophages when investigated in bone marrow-derived macrophages (BMDM) assay (IC50 = 56 nM and 167 nM, respectively, 164 nM for sorafenib). The safety and selectivity of these compounds were confirmed when tested against normal cell lines. Their safety profile was further confirmed using hERG assay. In silico studies were carried out to investigate their binding modes in the active site of FMS kinase, and to develop a QSAR model for these new motifs.

Exploring the therapeutic potential of a novel series of imidazothiadiazoles targeting focal adhesion kinase (FAK) for pancreatic cancer treatment: synthesis, mechanistic insights and promising antitumor and safety profile

Focal Adhesion Kinase (FAK) is a non-receptor protein tyrosine kinase that plays a crucial role in various oncogenic processes related to cell adhesion, migration, proliferation, and survival. The strategic targeting of FAK represents a burgeoning approach to address resistant tumours, such as pancreatic ductal adenocarcinoma (PDAC). Herein, we report a new series of twenty imidazo[2,1-b][1, 3, 4]thiadiazole derivatives assayed for their antiproliferative activity against the National Cancer Institute (NCI-60) panel and a wide panel of PDAC models. Lead compound 10l exhibited effective antiproliferative activity against immortalised (SUIT-2, CAPAN-1, PANC-1, PATU-T, BxPC-3), primary (PDAC-3) and gemcitabine-resistant clone (PANC-1-GR) PDAC cells, eliciting IC50 values in the low micromolar range (1.04-3.44 µM), associated with a significant reduction in cell-migration and spheroid shrinkage in vitro. High-throughput kinase arrays revealed a significant inhibition of the FAK signalling network, associated to induction of cell cycle arrest in G2/M phase, suppression of tumour cell invasion and apoptosis induction. The high selectivity index/toxicity prompted studies using PDAC mouse xenografts, demonstrating significant inhibition of tumour growth and safety. In conclusion, compound 10l displayed antitumor activity and safety in both in vitro and in vivo models, emerging as a highly promising lead for the development of FAK inhibitors in PDAC.

Recent advances on anticancer and antimicrobial activities of directly-fluorinated five-membered heterocycles and their benzo-fused systems

Due to the importance of the fluorinated heterocycles as main components of marketed drugs where 20% of the anticancer and antibiotic drugs contain fluorine atoms, this review describes the reported five-membered heterocycles and their benzo-fused systems having directly connected fluorine atom(s). The in vivo and in vitro anticancer and antimicrobial activities of these fluorinated heterocycles are well reported. Some fluorinated heterocycles were found to be lead structures for drug design developments where their activities were almost equal to or exceeded the potency of the reference drugs. In most cases, the fluorine-containing heterocycles showed promising safety index via their reduced cytotoxicity in non-cancerous cell lines. SAR study assigned that fluorinated heterocycles having various electron-donating or electron-withdrawing substituents significantly affected the anticancer and antimicrobial activities.

Dichloroacetate for Cancer Treatment: Some Facts and Many Doubts

Rarely has a chemical elicited as much controversy as dichloroacetate (DCA). DCA was initially considered a dangerous toxic industrial waste product, then a potential treatment for lactic acidosis. However, the main controversies started in 2008 when DCA was found to have anti-cancer effects on experimental animals. These publications showed contradictory results in vivo and in vitro such that a thorough consideration of this compound's in cancer is merited. Despite 50 years of experimentation, DCA's future in therapeutics is uncertain. Without adequate clinical trials and health authorities' approval, DCA has been introduced in off-label cancer treatments in alternative medicine clinics in Canada, Germany, and other European countries. The lack of well-planned clinical trials and its use by people without medical training has discouraged consideration by the scientific community. There are few thorough clinical studies of DCA, and many publications are individual case reports. Case reports of DCA's benefits against cancer have been increasing recently. Furthermore, it has been shown that DCA synergizes with conventional treatments and other repurposable drugs. Beyond the classic DCA target, pyruvate dehydrogenase kinase, new target molecules have also been recently discovered. These findings have renewed interest in DCA. This paper explores whether existing evidence justifies further research on DCA for cancer treatment and it explores the role DCA may play in it.

Biological activity and computational analysis of novel acrylonitrile derived benzazoles as potent antiproliferative agents for pancreatic adenocarcinoma with antioxidative properties

Continuing our research into the anticancer properties of acrylonitriles, we present a study involving the design, synthesis, computational analysis, and biological assessment of novel acrylonitriles derived from methoxy, hydroxy, and N-substituted benzazole. Our aim was to examine how varying the number of methoxy and hydroxy groups, as well as the N-substituents on the benzimidazole core, influences their biological activity. The newly synthesized acrylonitriles exhibited strong and selective antiproliferative effects against the Capan-1 pancreatic adenocarcinoma cell line, with IC50 values ranging from 1.2 to 5.3 μM. Consequently, these compounds were further evaluated in three other pancreatic adenocarcinoma cell lines, while their impact on normal PBMC cells was also investigated to determine selectivity. Among these compounds, the monohydroxy-substituted benzimidazole derivative 27 emerged with the most profound and broad-spectrum anticancer antiproliferative activity being emerged as a promising lead candidate. Moreover, a majority of the acrylonitriles in this series exhibited significant antioxidative activity, surpassing that of the reference molecule BHT, as demonstrated by the FRAP assay (ranging from 3200 to 5235 mmolFe2+/mmolC). Computational analysis highlighted the prevalence of electron ionization in conferring antioxidant properties, with computed ionization energies correlating well with observed activities.

Successful Outcome of a Patient with Concomitant Pancreatic and Renal Carcinoma Receiving Secoisolariciresinol Diglucoside Therapy Alone: A Case Report

Introduction

Pancreatic cancer (PC) is among the deadliest malignancies. Kidney cancer (KC) is a common malignancy globally. Chemo- or radio-therapies are not very effective to control PC or KC, and overdoses often cause severe site reactions to the patients. As a result, novel treatment strategies with high efficacy but without toxic side effects are urgently desired. Secoisolariciresinol diglucoside (SDG) belongs to plant lignans with potential anticancer activities, but clinical evidence is not available in PC or KC treatment.

Patient Concerns

We report a rare case of an 83-year-old female patient with pancreatic and kidney occupying lesions that lacked the conditions to receive surgery or chemo- or radiotherapy.

Diagnosis

Pancreatic and kidney cancers.

Interventions

We gave dietary SDG to the patient as the only therapeutics.

Outcomes

SDG effectively halted progression of both PC and KC. All clinical manifestations, including bad insomnia, loss of appetite, stomach symptoms, and skin itching over the whole body, all disappeared. The initial massive macroscopic hematuria became microscopic and infrequent, and other laboratory results also gradually returned to normal. Most of the cancer biomarkers, initially high such as CEA, CA199, CA724, CA125, came down rapidly, among which CA199 changed most radically. This patient has had progression-free survival of one year so far.

Conclusion

These results demonstrate the potent inhibitory effects of SDG on PC and KC of this patient and provide promising novel therapeutics for refractory malignant tumors.

Recent advances in pyruvate dehydrogenase kinase inhibitors: Structures, inhibitory mechanisms and biological activities

Metabolism is reprogrammed in a variety of cancer cells to ensure their rapid proliferation. Cancer cells prefer to utilize glycolysis to produce energy as well as to provide large amounts of precursors for their division. In this process, cancer cells inhibit the activity of pyruvate dehydrogenase complex (PDC) by upregulating the expression of pyruvate dehydrogenase kinases (PDKs). Inhibiting the activity of PDKs in cancer cells can effectively block this metabolic transition in cancer cells, while also activating mitochondrial oxidative metabolism and promoting apoptosis of cancer cells. To this day, the study of PDKs inhibitors has become one of the research hotspots in the field of medicinal chemistry. Novel structures targeting PDKs are constantly being discovered, and some inhibitors have entered the clinical research stage. Here, we reviewed the research progress of PDKs inhibitors in recent years and classified them according to the PDKs binding sites they acted on, aiming to summarize the structural characteristics of inhibitors acting on different binding sites and explore their clinical application value. Finally, the shortcomings of some PDKs inhibitors and the further development direction of PDKs inhibitors are discussed.

Targeting the pyruvate dehydrogenase complex/pyruvate dehydrogenase kinase (PDC/PDK) axis to discover potent PDK inhibitors through structure-based virtual screening and pharmacological evaluation

Proliferating cancer cells are characterized by the Warburg effect, a metabolic alteration in which ATP is generated from cytoplasmic glycolysis instead of oxidative phosphorylation. The pyruvate dehydrogenase complex/pyruvate dehydrogenase kinase (PDC/PDK) axis plays a crucial role in this effect and has been identified as a potential target for anticancer drug development. Herein, we present the discovery and pharmacological evaluation of potent PDK inhibitors targeting the PDK/PDC axis. We successfully identified 6 compounds from a small molecule library through a structure-based virtual screening campaign and evaluated their enzymatic inhibitory potencies for PDK1-4. Our results indicated that compound 1 exhibited submicromolar inhibitory activities against PDK1-3 (IC50 = 109.3, 135.8, and 458.7 nM, respectively), but is insensitive to PDK4 (IC50 = 8.67 μM). Furthermore, compound 1 inhibited the proliferation of A549 cells with an EC50 value of 10.7 μM. In addition, compound 1 induced cell apoptosis, arrested the cell cycle at the S phase, and reduced cell invasion and migration, while showing low in vivo toxicity at a high dose. Based on these observations, it can be concluded that compound 1 is a promising anti-PDK1-3 lead that merits further investigation.

An insight into the structure-activity relationship studies of anticancer medicinal attributes of 7-azaindole derivatives: a review

In the current portfolio, there is a lot of interest in the 7-azaindole building block for drug discovery. The creation of synthetic, sophisticated methods for the modification of 7-azaindoles is a promising area of research. This review covers the structure-activity relationship of 7-azaindole analogs, which have been shown to be effective anticancer agents in the literature of the past two decades. Positions 1, 3 and 5 of the 7-azaindole ring are the most active sites. Disubstitution is used for the synthesis of a new analog of the 7-azaindole moiety. All positions are used to create novel molecules that are effective anticancer agents. The alkyl, aryl carboxamide group and heterocyclic ring are the most successful types of substitution.

An Exploration of the Inhibitory Mechanism of Rationally Screened Benzofuran-1,3,4-Oxadiazoles and-1,2,4-Triazoles as Inhibitors of NS5B RdRp Hepatitis C Virus through Pharmacoinformatic Approaches

Benzofuran, 1,3,4-oxadiazole, and 1,2,4-triazole are privileged heterocyclic moieties that display the most promising and wide spectrum of biological activities against a wide variety of diseases. In the current study, benzofuran-1,3,4-oxadiazole BF1-BF7 and benzofuran-1,2,4-triazole compounds BF8-BF15 were tested against HCV NS5B RNA-dependent RNA polymerase (RdRp) utilizing structure-based screening via a computer-aided drug design (CADD) approach. A molecular docking approach was applied to evaluate the binding potential of benzofuran-appended 1,3,4-oxadiazole and 1,2,4-triazole BF1-BF15 molecules. Benzofuran-1,3,4-oxadiazole scaffolds BF1-BF7 showed lesser binding affinities (-12.63 to -14.04 Kcal/mol) than benzofuran-1,2,4-triazole scaffolds BF8-BF15 (-14.11 to -16.09 Kcal/mol) against the HCV NS5B enzyme. Molecular docking studies revealed the excellent binding affinity scores exhibited by benzofuran-1,2,4-triazole structural motifs BF-9 (-16.09 Kcal/mol), BF-12 (-15.75 Kcal/mol), and BF-13 (-15.82 Kcal/mol), respectively, which were comparatively better than benzofuran-based HCV NS5B inhibitors' standard reference drug Nesbuvir (-15.42 Kcal/mol). A molecular dynamics simulation assay was also conducted to obtain valuable insights about the enzyme-compounds interaction profile and structural stability, which indicated the strong intermolecular energies of the BF-9+NS5B complex and the BF-12+NS5B complex as per the MM-PBSA method, while the BF-12+NS5B complex was the most stable system as per the MM-GBSA calculation. The drug-likeness and ADMET studies of all the benzofuran-1,2,4-triazole derivatives BF8-BF15 revealed that these compounds possessed good medicinal chemistry profiles in agreement with all the evaluated parameters for being drugs. The molecular docking affinity scores, MM-PBSA/MM-GBSA and MD-simulation stability analysis, drug-likeness profiling, and ADMET study assessment indicated that N-4-fluorophenyl-S-linked benzofuran-1,2,4-triazole BF-12 could be a future promising anti-HCV NS5B RdRp inhibitor therapeutic drug candidate that has a structural agreement with the Nesbuvir standard reference drug.

Reprogramming Energy Metabolism with Synthesized PDK Inhibitors Based on Dichloroacetate Derivatives and Targeted Delivery Systems for Enhanced Cancer Therapy

In many types of cancers, pyruvate dehydrogenase kinase (PDK) is abnormally overexpressed and has become a promising target for cancer therapy. However, few highly effective inhibitors of PDK have been reported to date. Herein, we designed and synthesized a series of PDK inhibitors based on dichloroacetate (DCA) and arsenicals. Of the 27 compounds, 1f demonstrated PDK inhibition with high efficiency at a cellular level (IC50 = 2.0 μM) and an enzyme level (EC50 = 68 nM), far more effective than that of DCA. In silico, in vitro, and in vivo studies demonstrated that 1f inhibited PDK, shifted the energy metabolism from aerobic glycolysis to oxidative phosphorylation, and induced cell apoptosis. Moreover, new 1f-loaded nanoparticles were developed, and the administration of high-drug-loading nanoparticles (0.15 mg/kg) caused up to 90% tumor shrinkage without any apparent toxicity. Hence, this study provided a novel metabolic therapy for cancer treatment.

Colon Metastasis from Pancreatic Cancer: A Case Report

Pancreatic cancer commonly metastasizes to the liver, lung or adrenal glands, but rarely spreads to the colon. We describe a case of a 65-year-old man with operation history of endoscopic submucosal dissection for rectal adenoma, who visited our department with a lesion in the sigmoid colon. A biopsy of the sigmoid pathologic lesion found heterologous cells in the muscularis mucosa, which indicated that this lesion did not originate in the colon. Abdominal enhanced CT results revealed a soft tissue mass in pancreatic tail and several masses in the liver and rectovesical pouch. 18-FDG PET-scan results showed pancreatic neoplastic mass. Biopsy result of pancreatic pathologic area was positive for ductal pancreatic adenocarcinoma. Immunohistochemical staining confirmed that the sigmoid lesion was a metastasis from a primary pancreatic adenocarcinoma-an unusual pattern of spread. The patient accepted chemotherapy after an oncologic evaluation. To our knowledge, there were only nine reported cases of metastatic pancreatic cancer spreading to the colon. This was a rare route of metastasis for pancreatic cancer. It is important to keep this possibility in mind when patients present with a colon lesion. Furthermore, our case highlights the importance of considering metastases when a colon mass is found in patients with a history of colon cancer, although primary colon cancer is still more likely.

Nortopsentins as Leads from Marine Organisms for Anticancer and Anti-Inflammatory Agent Development

The marine environment is an excellent source of molecules that have a wide structural diversity and a variety of biological activities. Many marine natural products (MNPs) have been established as leads for anticancer drug discovery. Most of these compounds are alkaloids, including several chemical subclasses. In this review, we focus on the bis-indolyl alkaloid Nortopsentins and their derivatives with antiproliferative properties. Nortopsentins A-C were found to exhibit in vitro cytotoxicity against the P388 murine leukaemia cell line. Their structural manipulation provided a wide range of derivatives with significant anti-tumour activity against human cell lines derived from different cancer types (bladder, colon, gastric, CNS, liver, lung, breast, melanoma, ovarian, pancreatic, prostate, pleural mesothelioma, renal, sarcoma, and uterus). In vivo assays on animal models also proved that Nortopsentins and related bis-indolyl compounds have potent anti-inflammatory activity. These remarks set the foundation for future investigations into the development of new Nortopsentin derivatives as new anticancer and anti-inflammatory agents.

Quinoxaline 1,4-Dioxides: Advances in Chemistry and Chemotherapeutic Drug Development

N-Oxides of heterocyclic compounds are the focus of medical chemistry due to their diverse biological properties. The high reactivity and tendency to undergo various rearrangements have piqued the interest of synthetic chemists in heterocycles with N-oxide fragments. Quinoxaline 1,4-dioxides are an example of an important class of heterocyclic N-oxides, whose wide range of biological activity determines the prospects of their practical use in the development of drugs of various pharmaceutical groups. Derivatives from this series have found application in the clinic as antibacterial drugs and are used in agriculture. Quinoxaline 1,4-dioxides present a promising class for the development of new drugs targeting bacterial infections, oncological diseases, malaria, trypanosomiasis, leishmaniasis, and amoebiasis. The review considers the most important methods for the synthesis and key directions in the chemical modification of quinoxaline 1,4-dioxide derivatives, analyzes their biological properties, and evaluates the prospects for the practical application of the most interesting compounds.

Design, Synthesis, and Biological Evaluation of New Potential Unusual Modified Anticancer Immunomodulators for Possible Non-Teratogenic Quinazoline-Based Thalidomide Analogs

Sixteen new thalidomide analogs were synthesized. The new candidates showed potent in vitro antiproliferative activities against three human cancer cell lines, namely hepatocellular carcinoma (HepG-2), prostate cancer (PC3), and breast cancer (MCF-7). It was found that compounds XII, XIIIa, XIIIb, XIIIc, XIIId, XIVa, XIVb, and XIVc showed IC50 values ranging from 2.03 to 13.39 µg/mL, exhibiting higher activities than thalidomide against all tested cancer cell lines. Compound XIIIa was the most potent candidate, with an IC50 of 2.03 ± 0.11, 2.51 ± 0.2, and 0.82 ± 0.02 µg/mL compared to 11.26 ± 0.54, 14.58 ± 0.57, and 16.87 ± 0.7 µg/mL for thalidomide against HepG-2, PC3, and MCF-7 cells, respectively. Furthermore, compound XIVc reduced the expression of NFκB P65 levels in HepG-2 cells from 278.1 pg/mL to 63.1 pg/mL compared to 110.5 pg/mL for thalidomide. Moreover, compound XIVc induced an eightfold increase in caspase-8 levels with a simultaneous decrease in TNF-α and VEGF levels in HepG-2 cells. Additionally, compound XIVc induced apoptosis and cell cycle arrest. Our results reveal that the new candidates are potential anticancer candidates, particularly XIIIa and XIVc. Consequently, they should be considered for further evaluation for the development of new anticancer drugs.

1,3,4-Oxadiazole and 1,3,4-Thiadiazole Nortopsentin Derivatives against Pancreatic Ductal Adenocarcinoma: Synthesis, Cytotoxic Activity, and Inhibition of CDK1

A new series of nortopsentin analogs, in which the central imidazole ring of the natural lead was replaced by a 1,3,4-oxadiazole or 1,3,4-thiadiazole moiety, was efficiently synthesized. The antiproliferative activity of all synthesized derivatives was evaluated against five pancreatic ductal adenocarcinoma (PDAC) cell lines, a primary culture and a gemcitabine-resistant variant. The five more potent compounds elicited EC₅₀ values in the submicromolar-micromolar range, associated with a significant reduction in cell migration. Moreover, flow cytometric analysis after propidium iodide staining revealed an increase in the G2-M and a decrease in G1-phase, indicating cell cycle arrest, while a specific ELISA demonstrated the inhibition of CDK1 activity, a crucial regulator of cell cycle progression and cancer cell proliferation.

Azaindole derivatives as potential kinase inhibitors and their SARs elucidation

Currently, heterocycles have occupied an important position in the fields of drug design. Among them, azaindole moiety is regarded as one privileged scaffold to develop therapeutic agents. Since two nitrogen atoms of azaindole increase the possibility to form hydrogen bonds in the adenosine triphosphate (ATP)-binding site, azaindole derivatives are important sources of kinase inhibitors. Moreover, some of them have been on the market or in clinical trials for the treatment of some kinase-related diseases (e.g., vemurafenib, pexidartinib, decernotinib). In this review, we focused on the recent development of azaindole derivatives as potential kinase inhibitors based on kinase targets, such as adaptor-associated kinase 1 (AAK1), anaplastic lymphoma kinase (ALK), AXL, cell division cycle 7 (Cdc7), cyclin-dependent kinases (CDKs), dual-specificity tyrosine (Y)-phosphorylation regulated kinase 1A (DYRK1A), fibroblast growth factor receptor 4 (FGFR4), phosphatidylinositol 3-kinase (PI3K) and proviral insertion site in moloney murine leukemia virus (PIM) kinases. Meanwhile, the structure-activity relationships (SARs) of most azaindole derivatives were also elucidated. In addition, the binding modes of some azaindoles complexed with kinases were also investigated during the SARs elucidation. This review may offer an insight for medicinal chemists to rationally design more potent kinase inhibitors bearing the azaindole scaffold.

Past, Present, and Future Perspectives on Computer-Aided Drug Design Methodologies

The application of computational approaches in drug discovery has been consolidated in the last decades. These families of techniques are usually grouped under the common name of "computer-aided drug design" (CADD), and they now constitute one of the pillars in the pharmaceutical discovery pipelines in many academic and industrial environments. Their implementation has been demonstrated to tremendously improve the speed of the early discovery steps, allowing for the proficient and rational choice of proper compounds for a desired therapeutic need among the extreme vastness of the drug-like chemical space. Moreover, the application of CADD approaches allows the rationalization of biochemical and interactive processes of pharmaceutical interest at the molecular level. Because of this, computational tools are now extensively used also in the field of rational 3D design and optimization of chemical entities starting from the structural information of the targets, which can be experimentally resolved or can also be obtained with other computer-based techniques. In this work, we revised the state-of-the-art computer-aided drug design methods, focusing on their application in different scenarios of pharmaceutical and biological interest, not only highlighting their great potential and their benefits, but also discussing their actual limitations and eventual weaknesses. This work can be considered a brief overview of computational methods for drug discovery.

Structural Manipulations of Marine Natural Products Inspire a New Library of 3-Amino-1,2,4-Triazine PDK Inhibitors Endowed with Antitumor Activity in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the main aggressive types of cancer, characterized by late prognosis and drug resistance. Among the main factors sustaining PDAC progression, the alteration of cell metabolism has emerged to have a key role in PDAC cell proliferation, invasion, and resistance to standard chemotherapeutic agents. Taking into account all these factors and the urgency in evaluating novel options to treat PDAC, in the present work we reported the synthesis of a new series of indolyl-7-azaindolyl triazine compounds inspired by marine bis-indolyl alkaloids. We first assessed the ability of the new triazine compounds to inhibit the enzymatic activity of pyruvate dehydrogenase kinases (PDKs). The results showed that most of derivatives totally inhibit PDK1 and PDK4. Molecular docking analysis was executed to predict the possible binding mode of these derivatives using ligand-based homology modeling technique. Evaluation of the capability of new triazines to inhibit the cell growth in 2D and 3D KRAS-wild-type (BxPC-3) and KRAS-mutant (PSN-1) PDAC cell line, was carried out. The results showed the capacity of the new derivatives to reduce cell growth with a major selectivity against KRAS-mutant PDAC PSN-1 on both cell models. These data demonstrated that the new triazine derivatives target PDK1 enzymatic activity and exhibit cytotoxic effects on 2D and 3D PDAC cell models, thus encouraging further structure manipulation for analogs development against PDAC.

Mutant K-Ras in Pancreatic Cancer: An Insight on the Role of Wild-Type N-Ras and K-Ras-Dependent Cell Cycle Regulation

The development of K-Ras independence may explain the failure of targeted therapy for pancreatic cancer (PC). In this paper, active N as well as K-Ras was shown in all human cell lines tested. In a cell line dependent on mutant K-Ras, it was shown that depleting K-Ras reduced total Ras activity, while cell lines described as independent had no significant decline in total Ras activity. The knockdown of N-Ras showed it had an important role in controlling the relative level of oxidative metabolism, but only K-Ras depletion caused a decrease in G2 cyclins. Proteasome inhibition reversed this, and other targets of APC/c were also decreased by K-Ras depletion. K-Ras depletion did not cause an increase in ubiquitinated G2 cyclins but instead caused exit from the G2 phase to slow relative to completion of the S-phase, suggesting that the mutant K-Ras may inhibit APC/c prior to anaphase and stabilise G2 cyclins independently of this. We propose that, during tumorigenesis, cancer cells expressing wild-type N-Ras protein are selected because the protein protects cancer cells from the deleterious effects of the cell cycle-independent induction of cyclins by mutant K-Ras. Mutation independence results when N-Ras activity becomes adequate to drive cell division, even in cells where K-Ras is inhibited.