Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal cancer characterized by late diagnosis, aggressiveness, metabolic plasticity, and resistance to therapy, underscoring the need for new molecular targets. Pyruvate dehydrogenase kinases (PDKs), particularly PDK1 and PDK4, drive metabolic reprogramming and tumor progression, making them attractive therapeutic targets. However, current PDK inhibitors show limited potency and selectivity. Recent 3-amino-1,2,4-triazine derivatives have demonstrated promising PDK1/PDK4 inhibition and antiproliferative activity in PDAC cells, leading to the design of a new library of sixty triazine compounds, here in reported. Several compounds exhibited strong inhibitory activity against PDK1 and PDK4, with IC50 values ranging from 0.06 to 1.1 μM, demonstrating markedly higher potency compared to DCA and pronounced isoform selectivity. Molecular modeling and supervised molecular dynamics simulations supported these findings, revealing stable binding of representative compounds within the nucleotide-binding pocket of PDK1, involving key interactions with Asp318, Arg286, and Lys327. Functionally, the compounds displayed potent antiproliferative activity in both KRAS wild-type and mutant PDAC cell lines, with micromolar IC50 values. In three-dimensional pancreatic cancer spheroid models, the most active derivatives outperformed gemcitabine by approximately threefold and exceeded the activity of DCA-derived PDK inhibitors by ∼1.7-fold. Mechanistically, the novel amino-triazines disrupted the PDK/PDH axis, inducing a metabolic shift toward oxidative phosphorylation, impairing mitochondrial function, and triggering apoptotic cell death in KRAS-mutant PSN-1 cells. Overall, these results identify amino-triazine-based scaffolds as a promising new class of potent and selective PDK inhibitors with significant anticancer potential in pancreatic cancer.

Aim: The current study aims to investigate the critical role of the focal adhesion kinase (FAK) oncogenic signaling pathway in mediating drug resistance to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (EGFR-TKIs) and evaluate the potential of two novel FAK inhibitors, 10k and 10l, as therapeutic strategies for drug resistant non-small cell lung cancer (NSCLC). Methods: EGFR-TKI resistance in NSCLC cells was developed via stepwise drug selection. Kinases/polymerase chain reaction (PCR) arrays identified key resistance determinants, while reverse transcription quantitative polymerase chain reaction (RT-qPCR), enzyme-linked immunosorbent assay (ELISA), and immunohistochemistry evaluated FAK messenger RNA and phosphorylation levels. Antitumor activities were assessed using sulforhodamine-B, clonogenic, wound-healing, and apoptosis assays, spheroids and xenografts. Results: FAK was identified as a key driver of acquired resistance to EGFR-TKIs. High FAK expression predicted poor prognosis in patients treated with EGFR-TKIs. Kinase and PCR profiling confirmed elevated FAK levels as a resistance mechanism. Compounds 10k and 10l reduced phosphorylated FAK and showed strong anti-proliferative, anti-migratory, and pro-apoptotic effects in both EGFR-TKI-sensitive and -resistant cells. Notably, these compounds were shown to resensitize resistant NSCLC cells to EGFR-TKIs, with 10k inhibiting tumor growth and enhancing Osimertinib efficacy in resistant xenografts. Conclusion: These findings not only uncover a pivotal mechanism of EGFR-TKI drug resistance but also highlight innovative, promising therapeutic options for patients with therapy-refractory disease.

Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest malignancies, with limited effective therapeutic options due to late diagnosis, aggressive progression, and rapid development of drug resistance. In pursuit of novel treatments, this study reports the design, synthesis, and biological evaluation of a new series of topsentin derivatives, featuring a 1,2,4-oxadiazole core. The newly synthesized derivatives were screened for antiproliferative activity against multiple PDAC cell lines (SUIT-2, Patu-T, and PANC-1), identifying several compounds with potent growth-inhibitory effects, particularly on SUIT-2 and Patu-T cells. Further studies demonstrated that these compounds also significantly inhibited cell migration and reduced clonogenic potential, with IC50 values in the micromolar range. The results suggest that these marine-inspired 1,2,4-oxadiazole derivatives effectively target key hallmarks of PDAC, including proliferation, migration, and colony formation, supporting their further development as promising candidates for overcoming drug resistance and metastatic progression in pancreatic cancer.

INTRODUCTION:Cyclin-dependent kinase 7 (CDK7) is a key regulator of transcription and the cell cycle, with its dysregulation linked to tumorigenesis and chemoresistance. CDK7 serves as an unfavorable prognostic marker in multiple cancers and is significantly overexpressed in patients with poor prognosis, including those with lung and pancreatic cancer. AREAS COVERED:This review explores the role of CDK7 in tumorigenesis, focusing on transcriptional regulation, tumor metabolism, and therapy resistance. The development of CDK7 inhibitors has gained attention as a potential strategy to overcome chemoresistance. Notably, cancer cells exhibit sensitivity to CDK7 inhibitors at doses well tolerated by normal cells, supporting their clinical applicability. This review examines key CDK7 inhibitors, including THZ1, LDC4297, and YKL-5-124, in non-small-cell lung cancer (NSCLC), small-cell lung cancer (SCLC), and pancreatic ductal adenocarcinoma (PDAC), highlighting their mechanisms and therapeutic potential. Resistance mechanisms and combination strategies with chemotherapy, targeted therapies, or immunotherapy are also discussed. EXPERT OPINION:Despite promising preclinical results, challenges remain, including specificity, biomarker identification, and clinical validation. Further research is needed to optimize dosing, address resistance, and translate CDK7 inhibitors into clinical practice. Lastly, ongoing and future clinical trials will be essential to determining their therapeutic potential in PDAC, NSCLC, and SCLC.

Pancreatic ductal adenocarcinoma (PDAC), the most prevalent form of pancreatic tumor, is one of the most aggressive and lethal tumor types. Cyclin-dependent kinase 7 (CDK7) has been recently identified as a promising target in multiple human and mouse PDAC preclinical tumor models, due to significant downregulation of gene transcription and preferential inhibition of the mitotic cell cycle. With the aim of finding new CDK7 inhibitors, new indolyl and 7-aza-indolyl pyrazolo [1,5-a]-1,3,5-triazine derivatives are efficiently synthesized and screened for antiproliferative activity against three immortalized cell lines (SUIT 2.28, PATU-T, PANC-1) of PDAC. 8 out of 33 derivatives show remarkable cytotoxicity with IC50 values ranging from 0.19 to 1.58 µM and remarkable inhibition of cell migration from the earliest time point of 4 h, persisting until 24 h. The two most active compounds are further evaluated in clinically relevant models,including gemcitabine-resistant and primary cells (PATU-T GR, PDAC3), confirming their potent activity. They induce apoptosis, upregulate apoptotic gene expression, and disrupt the cell cycle, significantly reducing the viability of spheroidal PATU-T cultures. Additionally, both compounds effectively inhibit CDK7, as demonstrated by an enzyme-linked immunosorbent assay in cell extracts and by a specific enzymatic activity assay.

The tumor microenvironment (TME) is integral to cancer progression, impacting metastasis and treatment response. It consists of diverse cell types, extracellular matrix components, and signaling molecules that interact to promote tumor growth and therapeutic resistance. Elucidating the intricate interactions between cancer cells and the TME is crucial in understanding cancer progression and therapeutic challenges. A critical process induced by TME signaling is the epithelial-mesenchymal transition (EMT), wherein epithelial cells acquire mesenchymal traits, which enhance their motility and invasiveness and promote metastasis and cancer progression. By targeting various components of the TME, novel investigational strategies aim to disrupt the TME’s contribution to the EMT, thereby improving treatment efficacy, addressing therapeutic resistance, and offering a nuanced approach to cancer therapy. This review scrutinizes the key players in the TME and the TME's contribution to the EMT, emphasizing avenues to therapeutically disrupt the interactions between the various TME components. Moreover, the article discusses the TME’s implications for resistance mechanisms and highlights the current therapeutic strategies toward TME modulation along with potential caveats.

Cancer is a systemic manifestation of aberrant cell cycle activity and dysregulated cell growth. Genetic mutations can determine tumor onset by either augmenting cell division rates or restraining normal controls such as cell cycle arrest or apoptosis. As a result, tumor cells not only undergo uncontrolled cell division but also become compromised in their ability to exit the cell cycle accurately. Regulation of cell cycle progression is enabled by specific surveillance mechanisms known as cell cycle checkpoints, and aberrations in these signaling pathways often culminate in cancer. For instance, DNA damage checkpoints, which preclude the generation and augmentation of DNA damage in the G1, S, and G2 cell cycle phases, are often defective in cancer cells, allowing cell division in spite of the accumulation of genetic errors. Notably, tumors have evolved to become dependent on checkpoints for their survival. For example, checkpoint pathways such as the DNA replication stress checkpoint and the mitotic checkpoint rarely undergo mutations and remain intact because any aberrant activity could result in irreparable damage or catastrophic chromosomal missegregation leading to cell death. In this review, we initially focus on cell cycle control pathways and specific functions of checkpoint signaling involved in normal and cancer cells and then proceed to examine how cell cycle control and checkpoint mechanisms can provide new therapeutic windows that can be exploited for cancer therapy. SIGNIFICANCE STATEMENT: DNA damage checkpoints are often defective in cancer cells, allowing cell division in spite of the accumulation of genetic errors. Conversely, DNA replication stress and mitotic checkpoints rarely undergo mutations because any aberrant activity could result in irreparable damage or catastrophic chromosomal missegregation, leading to cancer cell death. This review focuses on the checkpoint signaling mechanisms involved in cancer cells and how an emerging understanding of these pathways can provide new therapeutic opportunities for cancer therapy.

The PI3K/Akt pathway is crucial in numerous cellular functions such as cell growth, survival proliferation and movement in both normal and cancer cells. It plays also a key role in epithelial-mesenchymal transitions and angiogenesis during the tumorigenesis processes. Since many transformative events in cancer are driven by increased PI3K/Akt pathway signaling, Akt is considered a valuable target for developing new therapies against various tumor types, including pancreatic cancer. This is because the PI3K/AKT/mTOR pathway is a key downstream effector of RAS, and RAS activation is the most prominent genetic alteration in pancreatic cancer. Herein we report the synthesis and the biological evaluation of a new series of azole urea compounds that exhibited promising antiproliferative and antimigratory activities against pancreatic cancer cells through an Akt inhibition mechanism. These effects were demonstrated using a variety of assays, including Sulforhodamine B, cell-cycle, wound-healing, and kinase activity, apotposis and ELISA assays. Additionally, the anticancer properties of the most active compound in the series were confirmed in the 3D spheroid model of PATU-T cells.

Extracellular vesicles (EVs) appear to play an important role in intercellular communication in various physiological processes and pathological conditions such as cancer. Like enveloped viruses, EVs can transport their contents into the nucleus of recipient cells, and a new intracellular pathway has been described to explain the nuclear shuttling of EV cargoes. It involves a tripartite protein complex consisting of vesicle-associated membrane protein-associated protein A (VAP-A), oxysterol-binding protein (OSBP)-related protein-3 (ORP3) and late endosome-associated Rab7 allowing late endosome entry into the nucleoplasmic reticulum. Rab7 binding to ORP3-VAP-A complex can be blocked by the FDA-approved antifungal drug itraconazole. Here, we design a new series of smaller triazole derivatives, which lack the dioxolane moiety responsible for the antifungal function, acting on the hydrophobic sterol-binding pocket of ORP3 and evaluate their structure-activity relationship through inhibition of VOR interactions and nuclear transfer of EV and HIV-1 cargoes. Our investigation reveals that the most effective compounds that prevent nuclear transfer of EV cargo and productive infection by VSV-Gpseudotyped HIV-1 are those with a side chain between 1 and 4 carbons, linear or branched (methyl) on the triazolone region. These potent chemical drugs could find clinical applications either for nuclear transfer of cancer-derived EVs that impact metastasis or viral infection.

Pancreatic ductal adenocarcinoma (PDAC) poses significant challenges in terms of prognosis and treatment. Recent research has identified splicing deregulation as a new cancer hallmark. Herein, we investigated the largely uncharacterized alternative splicing profile and the key splicing factor SF3B1 in PDAC pancreatic cells and tissues as a potential discovery source of plausible drug targets and new predictive biomarkers of clinical outcome. The research involved a transcriptome-wide analysis, comparing profiles of splicing profiles in PDAC primary cells with normal ductal cells. This revealed more than 400 significant differential splicing events in genes involved in regulation of gene expression, primarily related to mRNA splicing, and metabolism of nucleic acids. PDAC cultures were highly sensitive to the SF3B1 modulators, E7107 and Pladienolide-B, showing IC50s in the low nanomolar range. These compounds induced apoptosis, associated to induction of the MCL-1/S splice variant. and reduced cell migration, associated to RON mis-splicing. In an orthotopic mouse model, E7107 showed promising results. Furthermore, we evaluated SF3B1 expression in specimens from 87 patients and found a significant association of SF3B1 expression with progression-free and overall survival. In conclusion, SF3B1 emerges as both a potential prognostic factor and therapeutic target in PDAC, impacting cell proliferation, migration, and apoptosis. These findings warrant future studies on this new therapeutic strategy against PDAC.

Biofilm-associated infections pose significant challenges in healthcare settings due to their resistance to conventional antimicrobial therapies. In the last decade, the marine environment has been a precious source of bioactive molecules, including numerous derivatives with antibiofilm activity. In this study, we reported the synthesis and the biological evaluation of a new series of twenty-two thiadiazopyrimidinone derivatives obtained by using a hybridization approach combining relevant chemical features of two important classes of marine compounds: nortopsentin analogues and Essramycin derivatives. The synthesized compounds were in vitro tested for their ability to inhibit biofilm formation and to disrupt mature biofilm in various bacterial strains. Among the tested compounds, derivative 8j exhibited remarkable dispersal activity against preformed biofilms of relevant Gram-positive and Gram-negative pathogens, as well as towards the fungus Candida albicans, showing BIC50 values ranging from 17 to 40 µg/mL. Furthermore, compound 8j was in vivo assayed for its toxicity and the anti-infective effect in a Galleria mellonella model. The results revealed a promising combination of anti-infective properties and a favorable toxicity profile for the treatment of severe chronic biofilm-mediated infections.

Pancreatic ductal adenocarcinoma (PDAC) is among the leading causes of cancer-related deaths worldwide. Focal adhesion kinase (FAK) is a nonreceptor tyrosine kinase often overexpressed in PDAC. FAK has been linked to cell migration, survival, proliferation, angiogenesis and adhesion. This review first highlights the chemoresistant nature of PDAC. Second, the role of FAK in PDAC cancer progression and resistance is carefully described. Additionally, it discusses recent developments of FAK inhibitors as valuable drugs in the treatment of PDAC, with a focus on diamine-substituted-2,4-pyrimidine-based compounds, which represent the most potent class of FAK inhibitors in clinical trials for the treatment of PDAC disease. To conclude, relevant computational studies performed on FAK inhibitors are reported to highlight the key structural features required for interaction with the protein, with the aim of optimizing this novel targeted therapy.

ABSTRACTFocal 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 tumors, 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 compound10lexhibited effective antiproliferative activity against immortalized (SUIT-2, CAPAN-1, PANC-1, PATU-T, BxPC-3), primary (PDAC-3) and gemcitabine-resistant clone (PANC-1-GR) PDAC cells, eliciting IC50values in the low micromolar range (1.04-3.44 µM), associated with a significant reduction in cell-migration and spheroid shrinkagein 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 tumor cell invasion and apoptosis induction. The low selectivity index/toxicity prompted studies using PDAC mouse xenografts, demonstrating significant inhibition of tumor growth and safety. In conclusion, compound10ldisplayed antitumor activity and safety in bothin vitroandin vivomodels, emerging as a highly promising lead for the development of FAK inhibitors in PDAC.

Cell cycle dysregulation is a hallmark of cancer that promotes eccessive cell division. Cyclin-dependent kinase 4 (CDK4) and cyclin-dependent kinase 6 (CDK6) are key molecules in the G1-to-S phase cell cycle transition and are crucial for the onset, survival, and progression of breast cancer (BC). Small-molecule CDK4/CDK6 inhibitors (CDK4/6i) block phosphorylation of tumor suppressor Rb and thus restrain susceptible BC cells in G1 phase. Three CDK4/6i are approved for the first-line treatment of patients with advanced/metastatic hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) BC in combination with endocrine therapy (ET). Though this has improved the clinical outcomes for survival of BC patients, there is no established standard next-line treatment to tackle drug resistance. Recent studies suggest that CDK4/6i can modulate other distinct effects in both BC and breast stromal compartments, which may provide new insights into aspects of their clinical activity. This review describes the biochemistry of the CDK4/6-Rb-E2F pathway in HR+ BC, then discusses how CDK4/6i can trigger other effects in BC/breast stromal compartments, and finally outlines the mechanisms of CDK4/6i resistance that have emerged in recent preclinical studies and clinical cohorts, emphasizing the impact of these findings on novel therapeutic opportunities in BC.

Pyruvate dehydrogenase kinases (PDKs) are serine/threonine kinases, that are directly involved in altered cancer cell metabolism, resulting in cancer aggressiveness and resistance. Dichloroacetic acid (DCA) is the first PDK inhibitor that has entered phase II clinical; however, several side effects associated with weak anticancer activity and excessive drug dose (100 mg/kg) have led to its limitation in clinical application. Building upon a molecular hybridization approach, a small library of 3-amino-1,2,4-triazine derivatives has been designed, synthesized, and characterized for their PDK inhibitory activity using in silico, in vitro, and in vivo assays. Biochemical screenings showed that all synthesized compounds are potent and subtype-selective inhibitors of PDK. Accordingly, molecular modeling studies revealed that a lot of ligands can be properly placed inside the ATP-binding site of PDK1. Interestingly, 2D and 3D cell studies revealed their ability to induce cancer cell death at low micromolar doses, being extremely effective against human pancreatic KRAS mutated cancer cells. Cellular mechanistic studies confirm their ability to hamper the PDK/PDH axis, thus leading to metabolic/redox cellular impairment, and to ultimately trigger apoptotic cancer cell death. Remarkably, preliminary in vivo studies performed on a highly aggressive and metastatic Kras-mutant solid tumor model confirm the ability of the most representative compound 5i to target the PDH/PDK axis in vivo and highlighted its equal efficacy and better tolerability profile with respect to those elicited by the reference FDA approved drugs, cisplatin and gemcitabine. Collectively, the data highlights the promising anticancer potential of these novel PDK-targeting derivatives toward obtaining clinical candidates for combatting highly aggressive KRAS-mutant pancreatic ductal adenocarcinomas.

We here investigated the anti-inflammatory activity of a polymethoxylated flavone-containing fraction (PMFF) from Citrus sinensis and of a prenylflavonoid-containing one (PFF) from Humulus lupulus, either alone or in combination (MIX). To this end, an in vitro model of inflammatory bowel disease (IBD), consisting of differentiated, interleukin (IL)-1β-stimulated Caco-2 cells, was employed. We demonstrated that non-cytotoxic concentrations of either PMFF or PFF or MIX reduced nitric oxide (NO) production while PFF and MIX, but not PMFF, also inhibited prostaglandin E2 release. Coherently, MIX suppressed both inducible NO synthase and cyclooxygenase-2 over-expression besides NF-κB activation. Moreover, MIX increased nuclear factor erythroid 2–related factor 2 (Nrf2) activation, heme oxygenase-1 expression, restoring GSH and reactive oxygen and nitrogen species (RONs) levels. Remarkably, these effects with MIX were stronger than those produced by PMFF or PFF alone. Noteworthy, nobiletin (NOB) and xanthohumol (XTM), two of the most represented phytochemicals in PMFF and PFF, respectively, synergistically inhibited RONs production. Overall, our results demonstrate that MIX enhances the anti-inflammatory and anti-oxidative effects of the individual fractions in a model of IBD, via a mechanism involving modulation of NF-κB and Nrf2 signalling. Synergistic interactions between NOB and XTM emerge as a relevant aspect underlying this evidence.

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.