Challenges for the Clinical Development of PI3K Inhibitors: Strategies to Improve Their Impact in Solid Tumors

Targeting PI3K in cancer treatment: A comprehensive review with insights from clinical outcomes

The phosphoinositide 3-kinase (PI3K) pathway plays a crucial role in cancer, including cell growth, survival, metabolism, and metastasis. Its major role in tumor growth makes it a key target for cancer therapeutics, offering significant potential to slow tumor progression and enhance patient outcomes. Gain-of-function mutations, gene amplifications, and the loss of regulatory proteins like PTEN are frequently observed in malignancies, contributing to tumor development and resistance to conventional treatments such as chemotherapy and hormone therapy. As a result, PI3K inhibitors have received a lot of interest in cancer research. Several kinds of small-molecule PI3K inhibitors have been developed, including pan-PI3K inhibitors, isoform-specific inhibitors, and dual PI3K/mTOR inhibitors, each targeting a distinct component of the pathway. Some PI3K inhibitors such as idelalisib, copanlisib, duvelisib, alpelisib, and umbralisib have received FDA-approval, and are effective in the treatment of breast cancer and hematologic malignancies. Despite promising results in preclinical and clinical trials, the overall clinical success of PI3K inhibitors has been mixed. While some patients may get substantial advantages, a considerable number of them acquire resistance as a result of feedback activation of alternative pathways, adaptive tumor responses, and treatment-emergent mutations. The resistance mechanisms provide barriers to the sustained efficacy of PI3K-targeted treatments. This study reviews recent advancements in PI3K inhibitors, covering their clinical status, mechanism of action, resistance mechanisms, and strategies to overcome resistance.

Metabolomics integrated genomics approach: Understanding multidrug resistance phenotype in MCF-7 breast cancer cells exposed to doxorubicin and ABCA1/EGFR/PI3k/PTEN crosstalk

Resistance of cancer cells, especially breast cancer, to therapeutic medicines represents a major clinical obstacle that impedes the stages of treatment. Carcinoma cells that acquire resistance to therapeutic drugs can reprogram their own metabolic processes as a way to overcome the effectiveness of treatment and continue their reproduction processes. Despite the recent developments in medical research in the field of drug resistance, which showed some explanations for this phenomenon, the real explanation, along with the ability to precisely predict the possibility of its occurrence in breast cancer cells, still necessitates a deep consideration of the dynamics of the tumor's response to treatment. For this purpose the current study, combined both in vitro metabolomics and in vivo genomics analysis as the most advanced omics technologies that can provide a potential en route for inventing novel strategies to perform prospective, prognostic and diagnostic biomarkers for drug resistance phenomena in mammary cancer. Doxorubicin is the currently available breast cancer chemotherapeutic medication nevertheless; it was demonstrated to cause drug resistance, which impairs patient survival and prognosis by prompting proliferation, cell cycle progression, and preventing apoptosis, interactions between signaling pathways triggered drug resistance. In this research, in vitro metabolomics analysis based on GC-MS coupled with multivariable analysis was performed on MCF-7 and DOX resistant cell lines; MCF-7/adr cultured cells in addition to, further in vivo confirmation via inducing mammary cancer in rats via two doses of 7,12-dimethylbenz(a) anthracene (DMBA) (50 mg/kg and 25 mg/kg) proceeded by doxorubicin (5 mg/kg) treatment for one month. The metabolomics in vitro results pointed out that mannitol, myoinositol, glycine, α-linolenic acid, oleic acid and stearic acid have AUC values: 0.14, 0.5, 0.7, 0.1, 0.02, -0.02 (1, 1) respectively. Glycine and myoinositol metabolites provided the best discriminative power in the wild and resistance MCF-7 phenotypes. Meanwhile, in vivo results revealed a significant crosstalk between the alternation in oxidative stress biomarkers as well as Arginase II tumor biomarker and the molecular assessment of ABCA1 and P53 gene expression that displayed a marked reduction in addition to, the obvious elevation in resistance and apoptotic biomarkers EGFR/PI3k/AKT/PTEN signaling pathway upon DMBA administration. Data revealed a significant alternation in signaling pathways related to resistance upon doxorubicin administration that affect lipid metabolism in breast cancer. In conclusion, Metabolomics integrated genomics analysis may be promising in understanding multidrug resistance phenotype in MCF-7 breast cancer cells exposed to doxorubicin through modulating ABCA1/EGFR/P53/PI3k/PTEN signaling pathway thus metabolic biomarkers in addition to molecular biomarkers elucidate the challenges fronting profitable therapy of mammary cancer and an pioneering approaches that metabolomics compromises to improve recognizing drug resistance in breast carcinoma.

N-(5-(2-morpholino-4-oxo-3,4-dihydroquinazolin-8-yl)pyridin-2-yl)acylamides as novel multi-PI3K/DNA-PK/P-gp inhibitors for efficient chemosensitization and MDR alleviation

PI3K signaling pathway is crucial for a plethora of cellular processes and is extensively linked with tumorigenesis and chemo-/radioresistance. Although a number of small molecule inhibitors have been synthesized to control PI3K-mediated signaling, only a limited clinical success has been reached. Thus, the search for novel promising candidates is still ongoing. Herein, we present a novel series of N-(5-(2-morpholino-4-oxo-3,4-dihydroquinazolin-8-yl)pyridin-2-yl)acylamides designed to simultaneously inhibit PI3K and DNA-PK activity. Compared to a commercial DNA-PK/PI3K inhibitor AZD7648, synthesized compounds generally exhibited markedly lower baseline cytotoxicity in all tested cell lines (MC38, B16F10, 4T1, CT26 and HEK-239). Through an array of biological experiments, we selected two most promising compounds, 2 and 6. While in cell-free conditions, 6 acted as a very efficient pan-PI3K and DNA-PK inhibitor, in physiological conditions, 2 performed better and acted as a potent chemosensitizer able to increase the amount of DNA double strand breaks induced by doxorubicin. This was plausibly due to its improved ability to accumulate in nuclei as evidenced by confocal analyses. Importantly, using P-gp overexpressing CT26 cells, we found that 2 is an efficient inhibitor of multidrug resistance (MDR) able to down-regulate expression of mRNA encoding MDR-driving proteins ABCB1A, ABCB1B and ABCC1. We also demonstrate that 2 can be simply loaded into lipid nanoparticles that retain its chemosensitizing properties. Taken together, the presented study provides a solid basis for a subsequent rational structure optimization towards new generation of multitarget inhibitors able to control crucial signaling pathways involved in tumorigenesis and drug resistance.

Combinatorial screen of targeted agents with the PI3K inhibitors inavolisib, alpelisib, duvelisib, and copanlisib in multi-cell type tumor spheroids

Dysregulation of the phosphatidylinositol 3-kinase (PI3K) pathway is a key contributor to cancer, making PI3K inhibitors a promising approach for targeted therapy. The selectivity of available inhibitors varies across different PI3K isoforms. Alpelisib and inavolisib are selective for the α-isoform, while duvelisib targets the δ- and γ-isoforms, and copanlisib is a pan-PI3K inhibitor, active against all isoforms. This study investigated the activity of these four PI3K inhibitors in combination with other targeted agents using multi-cell type tumor spheroids composed of 60% malignant cells, 25% endothelial cells, and 15% mesenchymal stem cells. Twenty-nine tumor spheroid models were evaluated, including twenty-six patient-derived cancer cell lines from the NCI Patient-Derived Models Repository and three established cell lines from the NCI-60 human tumor cell line panel. Additive and/or synergistic effects were observed with alpelisib or inavolisib or copanlisib in combination with a RAS/MEK/ERK pathway inhibitor, either selumetinib (MEK), ravoxertinib (ERK 1/2), or tovorafenib (DAY101, RAF). Combinations of each of these three PI3K inhibitors with the KRAS mutation specific inhibitors MTRX1133 (KRAS G12D) or sotorasib (KRAS G12C) had selective activity in cell lines harboring the corresponding target. Lastly, combination effects were observed from vertical inhibition of the PI3K/AKT/mTOR pathway with a PI3K inhibitor in combination with either the mTORC1/2 inhibitor sapanisertib or an AKT inhibitor, ipatasertib or afuresertib.

Non-coding RNAs and regulation of the PI3K signaling pathway in lung cancer: Recent insights and potential clinical applications

Lung cancer (LC) is one of the most common causes of cancer-related death worldwide. It has been demonstrated that the prognosis of current drug treatments is affected by a variety of factors, including late stage, tumor recurrence, inaccessibility to appropriate treatments, and, most importantly, chemotherapy resistance. Non-coding RNAs (ncRNAs) contribute to tumor development, with some acting as tumor suppressors and others as oncogenes. The phosphoinositide 3-kinase (PI3Ks)/AKT serine/threonine kinase pathway is one of the most important common targets of ncRNAs in cancer, which is widely applied to modulate the cell cycle and a variety of biological processes, including cell growth, mobility survival, metabolic activity, and protein production. Discovering the biology of ncRNA-PI3K/AKT signaling may lead to advances in cancer diagnosis and treatment. As a result, we investigated the expression and role of PI3K/AKT-related ncRNAs in clinical characteristics of lung cancer, as well as their functions as potential biomarkers in lung cancer diagnosis, prognosis, and treatment.

Class III Phosphatidylinositol-3 Kinase/Vacuolar Protein Sorting 34 in Cardiovascular Health and Disease

Phosphatidylinositol-3 kinases (PI3Ks) play a critical role in maintaining cardiovascular health and the development of cardiovascular diseases (CVDs). Specifically, vacuolar Protein Sorting 34 (VPS34) or PIK3C3, the only member of Class III PI3K, plays an important role in CVD progression. The main function of VPS34 is inducing the production of phosphatidylinositol 3-phosphate, which, together with other essential structural and regulatory proteins in forming VPS34 complexes, further regulates the mammalian target of rapamycin activation, autophagy, and endocytosis. VPS34 is found to have crucial functions in the cardiovascular system, including dictating the proliferation and survival of vascular smooth muscle cells and cardiomyocytes and the formation of thrombosis. This review aims to summarize our current knowledge and recent advances in understanding the function and regulation of VPS34 in cardiovascular health and disease. We also discuss the current development of VPS34 inhibitors and their potential to treat CVDs.

The Effect and Treatment of PIK3CA Mutations in Breast Cancer: Current Understanding and Future Directions

Gene mutations in PIK3CA, the catalytic subunit of phosphoinositide 3-kinases, are significantly associated with prognosis in breast cancer. This association suggests that breast cancer patients with PIK3CA mutations should receive PIK3CA mutant-specific treatment. This review aimed to investigate novel treatments for PIK3CA-mutant breast cancer. This study investigated the effects of PIK3CA mutations in breast cancer with respect to gene ontology and the PI3K/AKT/mTOR pathway. Subsequently, we comprehensively examined all clinical trials that targeted breast cancer patients with PIK3CA mutations. Finally, this review explored the potential of a new treatment for noncoding RNA.

Targeting PI3K Signaling to Overcome Tumor Immunosuppression: Synergistic Strategies to Enhance Cancer Vaccine Efficacy

Phosphoinositide 3-kinases (PI3Ks), members of the lipid kinase family, play a significant role in modulating immune cell functions, including activation, proliferation, and differentiation. Recent studies have identified the PI3K signaling pathway as a key regulator in tumor biology and the immune microenvironment. This pathway enhances the activity of regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs), contributing to an immunosuppressive tumor microenvironment that impairs the effectiveness of cancer vaccines and immunotherapies. The present study explores PI3K isoforms, particularly p110γ and p110δ, and their associated signaling pathways. The therapeutic potential of selective PI3K inhibitors and their capacity to act synergistically with immunization strategies are analyzed. Targeting the PI3K signaling pathway represents a promising approach to counteract tumor-induced immune suppression and improve the efficacy of immune checkpoint inhibitors and vaccines, ultimately leading to better clinical outcomes.

Mechanism of PI3K/Akt‑mediated mitochondrial pathway in obesity‑induced apoptosis (Review)

Obesity is a pervasive global health challenge that substantially reduces the quality of life of millions of individuals and impedes social and economic advancement. Obesity is an independent risk factor that contributes to a range of chronic non-communicable metabolic diseases, significantly affecting energy metabolism, mental health, cancer susceptibility, sleep quality, and other physiological processes. The PI3K/AKT signaling pathway, a significant glucose, lipid, and protein metabolism regulator, is integral to cellular growth, survival, and apoptosis. Apoptosis is a highly regulated form of programmed cell death that is critical for immune cell maturation and tissue repair. The present review examines the association between obesity, the PI3K/AKT pathway, and mitochondrial apoptosis to elucidate the potential mechanisms by which obesity may activate apoptotic pathways. These findings provide a theoretical foundation for mitigating obesity-related complications by targeting these critical pathways.

Advancing Systemic Therapy in Chondrosarcoma: New Horizons

The systemic treatment landscape for advanced and metastatic chondrosarcoma, a malignancy with limited responsiveness to conventional therapies, has always been notoriously challenging. While standard chemotherapy offers minimal benefits, certain subtypes, such as mesenchymal and dedifferentiated chondrosarcomas, have shown some response to systemic therapies initially developed for other sarcomas. Investigational strategies are focusing on molecular targets, including mutations in the isocitrate dehydrogenase gene (IDH), signaling pathways, such as hedgehog and death receptor 5 (DR5) and immune modulation. IDH mutations, notably found in conventional and dedifferentiated chondrosarcomas, have prompted the evaluation of IDH inhibitors, which have demonstrated promising efficacy in preclinical and early clinical trials, despite limited data in chondrosarcoma. Additionally, the hedgehog pathway, implicated in chondrosarcoma progression, has been targeted with inhibitors, although clinical translation has shown mixed results. Immunotherapy, including programmed cell death 1 (PD-1) checkpoint inhibitors and chimeric antigen receptor-T (CAR-T) cells, is also being investigated but faces challenges due to the immunosuppressive tumour microenvironment. Among new approaches, DR5 agonists such as INBRX-109 have shown single-agent efficacy, with minimal toxicity, opening possibilities for use in combination therapies to improve outcomes. Given the heterogenous and treatment-resistant nature of chondrosarcoma, we highlight the need for multi-omics and genetic profiling to guide personalized, combination therapies that target multiple carcinogenic pathways. The integration of multi-targeted approaches could enhance efficacy, address tumour heterogeneity, and overcome resistance, presenting a hopeful direction for systemic therapy in this challenging cancer. The investigation of combination regimens with IDH inhibitors, immunotherapy and DR5 agonists hold promise for transforming the management of advanced chondrosarcoma.

Targeting PI3K signaling in Lung Cancer: advances, challenges and therapeutic opportunities

Lung cancer remains the leading cause of cancer-related mortality globally, necessitating the continual exploration of novel therapeutic targets. The phosphoinositide 3-kinase (PI3K) signaling pathway plays a pivotal role in oncogenic processes, including cell growth, survival, metabolism and immune modulation. This comprehensive review delineates the distinct roles of PI3K subtypes-PI3Kα, PI3Kβ, PI3Kγ and PI3Kδ-in lung cancer pathogenesis and progression. We evaluate the current landscape of PI3K inhibitors, transitioning from non-selective early-generation compounds to isoform-specific agents, highlighting their clinical efficacy, resistance mechanisms and potential combination strategies. Furthermore, the intricate interplay between PI3K signaling and the tumor immune microenvironment is explored, elucidating how PI3K modulation can enhance immunotherapeutic responses. Metabolic reprogramming driven by PI3K signaling is also dissected, revealing vulnerabilities that can be therapeutically exploited. Despite promising advancements, challenges such as therapeutic resistance and adverse effects underscore the need for personalized medicine approaches and the development of next-generation inhibitors. This review underscores the multifaceted role of PI3K in lung cancer and advocates for integrated strategies to harness its full therapeutic potential, paving the way for improved patient outcomes.

Blocking p85β nuclear translocation by importazole enhances Alpelisib efficacy against PIK3CA-helical-domain-mutant tumors

PIK3CA, which encodes protein p110α, is one of the most frequently mutated oncogenes and a promising drug-target for human cancer. Previously, we demonstrate that p85β is released from PI3K complex which contain PIK3CA helical domain mutations and translocates into nucleus to regulate tri-methylation of H3K27, thereby promoting tumorigenicity. Here, we identify DIRAS2 and SOWAHB as target genes of nuclear p85β in PIK3CA-helical-domain-mutant tumors. DIRAS2 and SOWAHB are tumor suppressive genes, whose expression are repressed by nuclear p85β through histone methyltransferase EZH2. More importantly, combination of PI3K inhibitor and importin-β inhibitor effectively inhibits the growth of PIK3CA-helical-domain-mutant tumors by synchronously blocking both AKT signaling and nuclear p85β/DIRAS2 and SOWAHB axis. In this study, we evaluate the combination effect of Alpelisib and Importazole for PIK3CA helical domain mutant tumors and demonstrate its underlying mechanism.

Alpelisib-Induced Hyperglycemia in PIK3CA+ Breast Cancer Patients

Alpelisib is a phosphatidylinositol 3-kinase inhibitor approved by the US Food and Drug Administration for the treatment of hormone receptor-positive metastatic breast cancer with PIK3CA (phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α) mutation. In recent years a number of adverse effects have been observed to be associated with this therapy, the most notable of which is hyperglycemia. A literature search was conducted to include case studies, case series, systematic reviews, and meta-analyses within the last 10 years that evaluated patients with PIK3CA-mutated hormone receptor-positive, human epidermal growth factor receptor 2 negative metastatic breast cancer. Hyperglycemia was a notable adverse effect that was found in the majority of patients without preexisting diabetes mellitus. Patients with hyperglycemia were in the high-risk groups of advanced age, prediabetes mellitus or history of insulin resistance, increased body mass index, increased blood monocyte count, and increased hemoglobin A1c (glycated hemoglobin). Hyperglycemia was manageable with antihyperglycemic agents and dose modification/discontinuation of alpelisib with no severe progression. Other notable adverse effects were rash, stomatitis, diarrhea, pneumonitis, reduced appetite, elevated liver enzymes, nausea, fatigue, and rare reports of diabetic ketoacidosis. This literature review aims to highlight the incidence and risk factors of alpelisib-induced hyperglycemia in greater depth.

An update on promising and emerging protein kinase B/AKT inhibitors for breast cancer

INTRODUCTION

The PI3K pathway is crucial in breast cancer (BC), influencing cell survival, growth, and metabolism, with AKT playing a central role in treatment resistance. This pathway's involvement in breast carcinogenesis and its link to treatment resistance underscores the significance of targeting it in BC therapy. PI3K-pathway inhibitors offer new therapeutic avenues but bring challenges, especially due to toxicity issues that hinder their development.

AREAS COVERED

This review discusses the PI3K-pathway inhibitors used in BC, highlighting emerging, innovative strategies.

EXPERT OPINION

The introduction of mTOR inhibitors marked a key step in tackling hormone receptor-positive (HR+) BC, targeting endocrine resistance. However, toxicity concerns remain, especially with PIK3CA and AKT inhibitors. Selective PI3K-targeted agents aim to reduce off-target toxicity, enhancing patient adherence and control over the disease. New compounds employing allosteric mechanisms may further limit adverse effects and allow safer combination therapies, previously limited by toxicity. Advancements in dosing strategies focus on patient-centered outcomes, and synergistic agents are essential in advancing AKT-pathway inhibition, paving the way for a new phase in HR+ BC treatment.

Phase II Study of Copanlisib in Patients With PTEN Loss: Results From NCI-MATCH ECOG-ACRIN Trial (EAY131) Subprotocols Z1G and Z1H

PURPOSE

Copanlisib, a pan-class phosphatidylinositol 3-kinase (PI3K) inhibitor with activity predominantly against the PI3K-delta and PI3K-alpha isoforms, has shown promising results in preclinical cancer models with PTEN loss. Herein, we report the activity and safety data from the Z1G and Z1H subprotocols, which included patients with PTEN loss, of the National Cancer Institute Molecular Analysis for Therapy Choice trial.

METHODS

Patients with complete loss of cytoplasmic and nuclear PTEN as determined by immunohistochemistry regardless of PTEN mutation or deletion status were included in subprotocol Z1G, and patients with a deleterious mutation in the PTEN gene and retained expression of PTEN were included in subprotocol Z1H. Copanlisib was given intravenously over 1 hour at a dose of 60 mg on days 1, 8, and 15 in a 21-day-on and 7-day-off schedule in 28-day cycles. Patients continued treatment until disease progression or unacceptable toxicity.

RESULTS

Overall, 49 patients (20 patients in Z1G and 29 in Z1H) were included in the primary efficacy analyses. The objective response rates in both cohorts were 0% (Z1G; 90% CI, 0 to 13.9) and 3.4% (Z1H; 90% CI, 0.2 to 15.3), respectively. The median progression-free and overall survival durations were 1.8 months (90% CI, 1.4 to 3.9 months) and 13.7 months (90% CI, 6.8 to 18.3 months) for the Z1G cohort and 1.8 months (90% CI, 1.8 to 2.1 months) and 9.0 months (90% CI, 5.4 to 13.3 months) for the Z1H cohort, respectively.

CONCLUSION

Our results do not support the antitumor activity of single-agent copanlisib in tumors with PTEN loss regardless of mutation or deletion status or PTEN deleterious mutations with PTEN expression.

Sodium selenite inhibits the growth of cervical cancer cells through the PI3K/AKT pathway

BACKGROUND

Selenium can inhibit cervical cancers, but the specific mechanism of anti-cervical cancer is not fully understood.

METHODS

In this study, we investigated the anti-cervical cancer effect of sodium selenite (SS) in vivo and in vitro to reveal the role of the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway in terms of the mechanism. In vivo experiments, HeLa cell xenografts were constructed in BALB/c female nude mice, and then intraperitoneally injected with 3 mg/kg sodium selenite (SS) for 14 days. In vitro experiments, we detected cell viability by MTT assay and apoptosis by Annexin V-FITC/PI staining. The levels of PI3K, AKT, phosphorylated PI3K (p-PI3K), and phosphorylated Akt (p-AKT) were measured by Western Blot.

RESULTS

HeLa cell xenografts in female nude mice showed delayed tumor growth and no apparent toxicity in the liver or kidney. SS reduced the viability and increased apoptosis of HeLa and SiHa cells. SS did not affect PI3K and AKT levels and decreased p-PI3K and p-AKT levels. In addition, the results also revealed that the SS combined with LY294002, a specific PI3K inhibitor, enhanced the inhibitory effect of SS on the PI3K/AKT signaling pathway, further inhibiting cervical cancer cell viability and increased apoptosis.

CONCLUSIONS

SS exerted its anti-cervical cancer effects by inhibiting cell proliferation, promoting apoptosis, and inhibiting the PI3K/AKT signaling pathway.

Heterogeneous nuclear ribonucleoprotein C promotes non-small cell lung cancer progression by enhancing XB130 mRNA stability and translation

BACKGROUND

XB130, a classical adaptor protein, exerts a critical role in diverse cellular processes. Aberrant expression of XB130 is closely associated with tumorigenesis and aggressiveness. However, the mechanisms governing its expression regulation remain poorly understood. Heterogeneous nuclear ribonucleoprotein C (hnRNPC), as an RNA-binding protein, is known to modulate multiple aspects of RNA metabolism and has been implicated in the pathogenesis of various cancers. We have previously discovered that hnRNPC is one of the candidate proteins that interact with the 3' untranslated region (3'UTR) of XB130 in non-small cell lung cancer (NSCLC). Therefore, this study aims to comprehensively elucidate how hnRNPC regulates the expression of XB130 in NSCLC.

MATERIALS AND METHODS

We evaluated the expression of hnRNPC in cancer and assessed the correlation between hnRNPC expression and prognosis in cancer patients using public databases. Subsequently, several stable cell lines were constructed. The proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of these cells were detected through Real-time cellular analysis, adherent colony formation, wound healing assay, invasion assay, and Western blotting. The specific regulatory manner between hnRNPC and XB130 was investigated by Real-time quantitative PCR, Western blotting, RNA pull‑down assay, dual‑luciferase reporter assay, RNA immunoprecipitation, and Co-Immunoprecipitation.

RESULTS

We identified that hnRNPC expression is significantly elevated in NSCLC and correlates with poor prognosis in patients with lung adenocarcinoma. HnRNPC overexpression in NSCLC cells increased the expression of XB130, subsequently activating the PI3K/Akt signaling pathway and ultimately promoting cell proliferation and EMT. Additionally, overexpressing XB130 in hnRNPC-silenced cells partially restored cell proliferation and EMT. Mechanistically, hnRNPC specifically bound to the 3'UTR segments of XB130 mRNA, enhancing mRNA stability by inhibiting the recruitment of nucleases 5'-3' exoribonuclease 1 (XRN1) and DIS3-like 3'-5' exoribonuclease 2 (DIS3L2). Furthermore, hnRNPC simultaneously interacted with the eukaryotic initiation factor 4E (eIF4E), a component of the eIF4F complex, facilitating the circularization of XB130 mRNA and thereby increasing its translation efficiency.

CONCLUSIONS

HnRNPC overexpression promotes NSCLC progression by enhancing XB130 mRNA stability and translation, suggesting that hnRNPC might be a potential therapeutic and prognostic target for NSCLC.

Synthesis, biological evaluation and mechanism study based on network pharmacology of amino acids esters of 20(S)-protopanaxadiol as novel anticancer agents

As one of the metabolites of ginseng, 20(S)-protopanaxadiol (PPD) is a compound with dammarane-type tetracyclic triterpene, which performs a wide range of anticancer activities. In this study, PPD was used as a lead. A series of compounds were synthesized respectively with 11 amino acids through esterification and were evaluated for their cytotoxicity against several cancer cell lines. One of the synthetic products (PL) exhibited potent inhibitory effect on Huh-7 cells relative to that of PPD in vitro. Subsequently, the Annexin V-FITC /PI staining assay was used to verify that PL induced apoptosis of Huh-7 cells in a dose-dependent manner. A UPLC-Q/TOF-MS analysis method was established and validated for assessing pharmacokinetic properties after the administration of PPD and PL in rats. The results showed that compared with PPD, T1/2of PL in rats was prolonged, and the peak time was delayed, resulting in broader tissue distribution of the compound in the body. In addition, the targets of PL against several cancers were predicted and analyzed via network pharmacology. Molecular docking simulations demonstrated that PL interacted with the active sites of the above targets. In conclusion, this study provided a theoretical basis for the development and clinical application of anti-tumor activity of PPD.

AKT and the Hallmarks of Cancer

Nearly a quarter century ago, Hanahan and Weinberg conceived six unifying principles explaining how normal cells transform into malignant tumors. Their provisional set of biological capabilities acquired during tumor development-cancer hallmarks-would evolve to 14 tenets as knowledge of cancer genomes, molecular mechanisms, and the tumor microenvironment expanded, most recently adding four emerging enabling characteristics: phenotypic plasticity, epigenetic reprogramming, polymorphic microbiomes, and senescent cells. AKT kinases are critical signaling molecules that regulate cellular physiology upon receptor tyrosine kinases and PI3K activation. The complex branching of the AKT signaling network involves several critical downstream nodes that significantly magnify its functional impact, such that nearly every organ system and cell in the body may be affected by AKT activity. Conversely, tumor-intrinsic dysregulation of AKT can have numerous adverse cellular and pathologic ramifications, particularly in oncogenesis, as multiple tumor suppressors and oncogenic proteins regulate AKT signaling. Herein, we review the mounting evidence implicating the AKT pathway in the aggregate of currently recognized hallmarks of cancer underlying the complexities of human malignant diseases. The challenges, recent successes, and likely areas for exciting future advances in targeting this complex pathway are also discussed.

Rapid, potent, and persistent covalent chemical probes to deconvolute PI3Kα signaling

Chemical probes have gained importance in the elucidation of signal transduction in biology. Insufficient selectivity and potency, lack of cellular activity and inappropriate use of chemical probes has major consequences on interpretation of biological results. The catalytic subunit of phosphoinositide 3-kinase α (PI3Kα) is one of the most frequently mutated genes in cancer, but fast-acting, high-quality probes to define PI3Kα's specific function to clearly separate it from other class I PI3K isoforms, are not available. Here, we present a series of novel covalent PI3Kα-targeting probes with optimized intracellular target access and kinetic parameters. On-target TR-FRET and off-target assays provided relevant kinetic parameters (k chem, k inact and K i) to validate our chemical probes. Additional intracellular nanoBRET tracer displacement measurements showed rapid diffusion across the cell membrane and extremely fast target engagement, while investigations of signaling downstream of PI3Kα via protein kinase B (PKB/Akt) and forkhead box O (FOXO) revealed blunted pathway activity in cancer cell lines with constitutively activated PI3Kα lasting for several days. In contrast, persistent PI3Kα inhibition was rapidly bypassed by other class I PI3K isoforms in cells lacking functional phosphatase and tensin homolog (PTEN). Comparing the rapidly-diffusing, fast target-engaging chemical probe 9 to clinical reversible PI3Kα-selective inhibitors alpelisib, inavolisib and 9r, a reversible analogue of 9, revealed 9's superior potency to inhibit growth (up to 600-fold) associated with sustained suppression of PI3Kα signaling in breast cancer cell lines. Finally, using a simple washout protocol, the utility of the highly-selective covalent PI3Kα probe 9 was demonstrated by the quantification of the coupling of insulin, EGF and CXCL12 receptors to distinct PI3K isoforms for signal transduction in response to ligand-dependent activation. Collectively, these findings along with the novel covalent chemical probes against PI3Kα provide insights into isoform-specific functions in cancer cells and highlight opportunities to achieve improved selectivity and long-lasting efficacy.

Predict the Drug-Drug Interaction of a Novel PI3Kα/δ Inhibitor, TQ-B3525, and Its Two Metabolites Using Physiologically Based Pharmacokinetic Modeling

A novel dual PI3K α/δ inhibitor, TQ-B3525, has been developed for the targeted treatment of lymphoma and solid tumors. TQ-B3525 is primarily metabolized by CYP3A4 and FOM3, while also serving as a substrate for the P-glycoprotein transporter. The aim of this study was to anticipate the drug-drug interaction (DDI) of TQ-B3525 and its two metabolites with CYP3A4 enzyme potent inducer (rifampicin) and CYP3A4/P-gp inhibitor (itraconazole) utilizing a physiologically based pharmacokinetic (PBPK) modeling approach. Clinical data from healthy and cancer patient adults were employed to construct and evaluate the PBPK model for TQ-B3525, M3, and M8-3. Models involving rifampicin combined with midazolam, itraconazole combined with midazolam or digoxin were utilized to showcase the robustness of evaluating DDI effects. The simulated drug exposure of TQ-B3525, M3, and M8-3 in healthy and patient adults were consistent with clinical data, and the mean fold error values were within the acceptable ranges. The simulated results of positive substrates correspond to those reported in the literature. Co-administration with rifampicin reduces Cmax and AUC of TQ-B3525 to 76.1% and 46.0%, while increasing the levels of M3 and M8-3. With itraconazole, Cmax and AUC of TQ-B3525 rise to 131% and 204%, but decrease substantially for M3 and M8-3. PBPK model simulation results showed that the systemic exposure of TQ-B3525 was significantly affected when co-administered with CYP3A4/P-gp inducers and inhibitors. This indicates that the combination with strong inducers and inhibitors should be carefully avoided or adjust the dosage of TQ-B3525 in clinic.

Oxidative Stress and Cancer Therapy: Controlling Cancer Cells Using Reactive Oxygen Species

Cancer is a multifaceted disease influenced by various mechanisms, including the generation of reactive oxygen species (ROS), which have a paradoxical role in both promoting cancer progression and serving as targets for therapeutic interventions. At low concentrations, ROS serve as signaling agents that enhance cancer cell proliferation, migration, and resistance to drugs. However, at elevated levels, ROS induce oxidative stress, causing damage to biomolecules and leading to cell death. Cancer cells have developed mechanisms to manage ROS levels, including activating pathways such as NRF2, NF-κB, and PI3K/Akt. This review explores the relationship between ROS and cancer, focusing on cell death mechanisms like apoptosis, ferroptosis, and autophagy, highlighting the potential therapeutic strategies that exploit ROS to target cancer cells.

Identification of novel inhibitors targeting PI3Kα via ensemble-based virtual screening method, biological evaluation and molecular dynamics simulation

PIK3CA gene encoding PI3K p110α is one of the most frequently mutated and overexpressed in majority of human cancers. Development of potent and selective novel inhibitors targeting PI3Kα was considered as the most promising approaches for cancer treatment. In this investigation, a virtual screening platform for PI3Kα inhibitors was established by employing machine learning methods, pharmacophore modeling, and molecular docking approaches. 28 potential PI3Kα inhibitors with different scaffolds were selected from the databases with 295,024 compounds. Among the 28 hits, hit15 exhibited the best inhibitory effect against PI3Kα with IC50 value less than 1.0 µM. The molecular dynamics simulation indicated that hit15 could stably bind to the active site of PI3Kα, interact with some residues by hydrophobic, electrostatic and hydrogen bonding interactions, and finally induced PI3Kα active pocket substantial conformation changes. Stable H-bond interactions were formed between hit15 and residues of Lys776, Asp810 and Asp933. The binding free energy of PI3Kα-hit15 was - 65.3 kJ/mol. The free energy decomposition indicated that key residues of Asp805, Ile848 and Ile932 contributed stronger energies to the binding free energy. The above results indicated that hit15 with novel scaffold was a potent PI3Kα inhibitor and considered as a promising candidate for further drug development to treat various cancers with PI3Kα over activated.

From lab to clinic: The discovery and optimization journey of PI3K inhibitors

PI3K inhibitors have emerged as promising therapeutic agents due to their critical role in various cellular processes, particularly in cancer, where the PI3K pathway is frequently dysregulated. This review explores the evolutionary path of PI3K inhibitors from laboratory discovery to clinical application. The journey begins with early laboratory investigations into PI3K signaling and inhibitor development, highlighting fundamental discoveries that laid the foundation for subsequent advancements. Optimization strategies, including medicinal chemistry approaches and structural modifications, are scrutinized for their contributions to enhancing inhibitor potency, selectivity, and pharmacokinetic properties. The translation from preclinical studies to clinical trials is examined, emphasizing pivotal trials that evaluated efficacy and safety profiles. Challenges encountered during clinical development are critically assessed. Finally, the review discusses ongoing research directions and prospects for PI3K inhibitors, underscoring these agents' continuous evolution and therapeutic potential.

Ferroptosis as a hero against oral cancer

Cancer is an abnormal condition altering the cells to proliferate out of control simultaneously being susceptible to evolution. The lining which is made up of tissues in the lips, upper throat and mouth can undergo mutations, is recognised as mouth cancer or oral cancer. Substantial number of mouth lesions are identified at a point where it is typically not possible to get effective remedial care. Ferroptosis is a cutting-edge instance of cellular destruction which stands out in distinction to other sorts of cell death. It appears to have distinctive cellular, molecular and gene-level attributes and scavenges on deposits of reactive oxygen species triggered via iron-induced lipid peroxidation. It is said to be involved dichotomously in cancer development. Because the ferroptotic tumour cells put out numerous chemicals that alternatively signal for cancer attenuation or growth. There is increasing proof that researchers are now keenly investigating to stimulate ferroptosis through various inducers and pathways in the intent for oral cancer therapeutics, specifically to kill malignant tumours that refuse to respond well to conventional treatments. Also, it has the ability to reverse chemotherapy and radiotherapy resistance in victims maximising the success rate of the treatments. This review centres on the stimulation of ferroptosis as a stand-alone therapy for oral cancer, or in combination with other medicines, agents and pathways.

ZSTK474 targeting PIK3R3 inhibits the Wilms' tumor through G0 / G1 phase arrest

PURPOSE

Wilms' tumor (WT), also known as nephroblastoma, is the predominant form of primary malignant renal cancer. The unfavorable prognoses linked to anaplastic nephroblastoma and recurrent nephroblastoma emphasize the crucial requirement for the exploration of innovative treatment modalities for WT.

METHODS

Our study conducted one-way Cox regression and Kaplan-Meier analyses using TARGET-WT nephroblastoma data to identify differentially expressed genes in nephroblastoma and evaluate their prognostic relevance. Utilizing the Connectivity Map database, ZSTK474 emerged as a viable therapeutic option for WT. The effect of ZSTK474 on WT and related underlying mechanisms were further investigated through in vitro and in vivo investigations.

RESULTS

The in vivo experiment results indicated that ZSTK474 effectively inhibited subcutaneous tumor growth in WT mice. CCK-8 assays revealed two nephroblastoma cell lines exhibited half-inhibitory concentrations of 2μM and 2.51μM for ZSTK474, respectively. ZSTK474 was shown to inhibit the migration and invasion capabilities of WT cells in both Transwell and wound healing assays. Flow cytometry apoptosis and TUNEL assays demonstrated that ZSTK474 induced apoptosis in WT cells. Cell cycle analysis revealed that ZSTK474 led to the induction of G0/G1 phase arrest. Sequencing of ZSTK474-treated WiT49 cells suggested that the impact of ZSTK474 on WT might be mediated by the PI3K/Akt pathway, specifically by inhibiting PIK3R3. Knock-down of PIK3R3 confirmed that ZSTK474 downregulated PIK3R3, reducing Akt phosphorylation, cyclin D and CDK4 levels and elevating P21 expression in nephroblastoma cells. However, current research has limitations, including a lack of understanding of the long-term effects and potential resistance mechanisms of new therapies.

CONCLUSION

This research provides insight into the potential of ZSTK474 and other PI3K inhibitors for treating nephroblastoma.

Functional Assessments of Gynecologic Cancer Models Highlight Differences Between Single-Node Inhibitors of the PI3K/AKT/mTOR Pathway and a Pan-PI3K/mTOR Inhibitor, Gedatolisib

Background/Objectives: The PI3K/AKT/mTOR (PAM) pathway is frequently activated in gynecological cancers. Many PAM inhibitors selectively target single PAM pathway nodes, which can lead to reduced efficacy and increased drug resistance. To address these limitations, multiple PAM pathway nodes may need to be inhibited. Gedatolisib, a well-tolerated panPI3K/mTOR inhibitor targeting all Class I PI3K isoforms, mTORC1 and mTORC2, could represent an effective treatment option for patients with gynecologic cancers. Methods: Gedatolisib and other PAM inhibitors (e.g., alpelisib, capivasertib, and everolimus) were tested in endometrial, ovarian, and cervical cancer cell lines by using cell viability, cell proliferation, and flow cytometry assays. Xenograft studies evaluated gedatolisib in combination with a CDK4/6 inhibitor (palbociclib) or an anti-estrogen (fulvestrant). A pseudo-temporal transcriptomic trajectory of endometrial cancer clinical progression was computationally modeled employing data from 554 patients to correlate non-clinical studies with a potential patient group. Results: Gedatolisib induced a substantial decrease in PAM pathway activity in association with the inhibition of cell cycle progression and the decreased cell viability in vitro. Compared to single-node PAM inhibitors, gedatolisib exhibited greater growth-inhibitory effects in almost all cell lines, regardless of the PAM pathway mutations. Gedatolisib combined with either fulvestrant or palbociclib inhibited tumor growth in endometrial and ovarian cancer xenograft models. Conclusions: Gedatolisib in combination with other therapies has shown an acceptable safety profile and promising preliminary efficacy in clinical studies with various solid tumor types. The non-clinical data presented here support the development of gedatolisib combined with CDK4/6 inhibitors and/or hormonal therapy for gynecologic cancer treatment.

Characterization of stem cell landscape and assessing the stemness degree to aid clinical therapeutics in hematologic malignancies

Hematological malignancies are a group of cancers that affect the blood, bone marrow, and lymphatic system. Cancer stem cells (CSCs) are believed to be responsible for the initiation, progression, and relapse of hematological malignancies. However, identifying and targeting CSCs presents many challenges. We aimed to develop a stemness index (HSCsi) to identify and guide the therapy targeting CSCs in hematological malignancies. We developed a novel one-class logistic regression (OCLR) algorithm to identify transcriptomic feature sets related to stemness in hematologic malignancies. We used the HSCsi to measure the stemness degree of leukemia stem cells (LSCs) and correlate it with clinical outcomes.We analyze the correlation of HSCsi with genes and pathways involved in drug resistance and immune microenvironment of acute myeloid leukemia (AML). HSCsi revealed stemness-related biological mechanisms in hematologic malignancies and effectively identify LSCs. The index also predicted survival and relapse rates of various hematologic malignancies. We also identified potential drugs and interventions targeting cancer stem cells (CSCs) of hematologic malignancies by the index. Moreover, we found a correlation between stemness and bone marrow immune microenvironment in AML. Our study provides a novel method and tool to assess the stemness degree of hematologic malignancies and its implications for clinical outcomes and therapeutic strategies. Our HSC stemness index can facilitate the precise stratification of hematologic malignancies, suggest possible targeted and immunotherapy options, and guide the selection of patients.

Preclinical assessment of the PI3Kα selective inhibitor inavolisib and prediction of its pharmacokinetics and efficacious dose in human

1. Small molecule inhibitors of the PI3K pathway have been extensively investigated as potential anticancer agents. Among the effectors in this pathway, PI3Kα is the kinase most frequently associated with the development of tumours, through mutations and amplifications of the PIK3CA gene encoding the p110α catalytic subunit.2. Inavolisib (GDC-0077) is a potent and PI3Kα-selective inhibitor that also specifically triggers the degradation of the mutant p110α protein.3. We characterised inavolisib ADME properties in preclinical in vitro and in vivo studies, assessed its efficacy in the PIK3CA mutant KPL-4 breast cancer xenograft model, and predicted its pharmacokinetics and efficacious dose in humans.4. Inavolisib had a moderate permeability (1.9•10-6 cm/s) in MDCK cells and was a P-gp and Bcrp1 substrate. It appeared metabolically stable in hepatocytes incubations from human and preclinical species. The systemic clearance was low in mouse, monkey and dog and high in rat. Oral bioavailability ranged from 57.5% to 100%. Inavolisib was efficacious in the KPL-4 sub-cutaneous xenograft model.5. The PK/PD model parameters estimated from the efficacy study, combined with PBPK model-predicted human PK profiles, projected that a dose of 3 mg could lead to clinical response. Inavolisib is currently being tested in phase 3 trials.

Targeting Cholesterol Biosynthesis with Statins Synergizes with AKT Inhibitors in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is responsible for a disproportionate number of breast cancer patient deaths due to extensive molecular heterogeneity, high recurrence rates, and lack of targeted therapies. Dysregulation of the phosphoinositide 3-kinase (PI3K)/AKT pathway occurs in approximately 50% of TNBC patients. Here, we performed a genome-wide CRISPR/Cas9 screen with PI3Kα and AKT inhibitors to find targetable synthetic lethalities in TNBC. Cholesterol homeostasis was identified as a collateral vulnerability with AKT inhibition. Disruption of cholesterol homeostasis with pitavastatin synergized with AKT inhibition to induce TNBC cytotoxicity in vitro in mouse TNBC xenografts and in patient-derived estrogen receptor (ER)-negative breast cancer organoids. Neither ER-positive breast cancer cell lines nor ER-positive organoids were sensitive to combined AKT inhibitor and pitavastatin. Mechanistically, TNBC cells showed impaired sterol regulatory element-binding protein 2 (SREBP-2) activation in response to single-agent or combination treatment with AKT inhibitor and pitavastatin, which was rescued by inhibition of the cholesterol-trafficking protein Niemann-Pick C1 (NPC1). NPC1 loss caused lysosomal cholesterol accumulation, decreased endoplasmic reticulum cholesterol levels, and promoted SREBP-2 activation. Taken together, these data identify a TNBC-specific vulnerability to the combination of AKT inhibitors and pitavastatin mediated by dysregulated cholesterol trafficking. These findings support combining AKT inhibitors with pitavastatin as a therapeutic modality in TNBC. Significance: Two FDA-approved compounds, AKT inhibitors and pitavastatin, synergize to induce cell death in triple-negative breast cancer, motivating evaluation of the efficacy of this combination in clinical trials.

Quantitative Assessment of Drug Efficacy and Emergence of Resistance in Patients with Metastatic Renal Cell Carcinoma Using a Longitudinal Exposure-Tumor Growth Inhibition Model: Apitolisib (Dual PI3K/mTORC1/2 Inhibitor) Versus Everolimus (mTORC1 Inhibitor)

Cancer remains a significant global health challenge, and despite remarkable advancements in therapeutic strategies, poor tolerability of drugs (causing dose reduction/interruptions) and/or the emergence of drug resistance are major obstacles to successful treatment outcomes. Metastatic renal cell carcinoma (mRCC) accounts for 2% of global cancer diagnoses and deaths. Despite the initial success of targeted therapies in mRCC, challenges remain to overcome drug resistance that limits the long-term efficacy of these treatments. Our analysis aim was to develop a semi-mechanistic longitudinal exposure-tumor growth inhibition model for patients with mRCC to characterize and compare everolimus (mTORC1) and apitolisib's (dual PI3K/mTORC1/2) ability to inhibit tumor growth, and quantitate each drug's efficacy decay caused by emergence of tumor resistance over time. Model-estimated on-treatment tumor growth rate constant was 1.7-fold higher for apitolisib compared to everolimus. Estimated half-life for loss of treatment effect over time for everolimus was 16.1 weeks compared to 7.72 weeks for apitolisib, suggesting a faster rate of tumor re-growth for apitolisib patients likely due to the emergence of resistance. Goodness-of-fit plots including visual predictive check indicated a good model fit and the model was able to capture individual tumor size-time profiles. Based on our knowledge, this is the first clinical report to quantitatively assess everolimus (mTORC1) and apitolisib (PI3K/mTORC1/2) efficacy decay in patients with mRCC. These results highlight the difference in overall efficacy of 2 drugs due to the quantified efficacy decay caused by emergence of resistance, and emphasize the importance of model-informed drug development for targeted cancer therapy.

A deep learning-based theoretical protocol to identify potentially isoform-selective PI3Kα inhibitors

Phosphoinositide 3-kinase alpha (PI3Kα) is one of the most frequently dysregulated kinases known for their pivotal role in many oncogenic diseases. While the side effects linked to existing drugs against PI3Kα-induced cancers provide an avenue for further research, the significant structural conservation among PI3Ks makes it extremely difficult to develop new isoform-selective PI3Kα inhibitors. Embracing this challenge, we herein designed a hybrid protocol by integrating machine learning (ML) with in silico drug-designing strategies. A deep learning classification model was developed and trained on the physicochemical descriptors data of known PI3Kα inhibitors and used as a screening filter for a database of small molecules. This approach led us to the prediction of 662 compounds showcasing appropriate features to be considered as PI3Kα inhibitors. Subsequently, a multiphase molecular docking was applied to further characterize the predicted hits in terms of their binding affinities and binding modes in the targeted cavity of the PI3Kα. As a result, a total of 12 compounds were identified whereas the best poses highlighted the efficiency of these ligands in maintaining interactions with the crucial residues of the protein to be targeted for the inhibition of associated activity. Notably, potential activity of compound 12 in counteracting PI3Kα function was found in a previous in vitro study. Following the drug-likeness and pharmacokinetic characterizations, six compounds (compounds 1, 2, 3, 6, 7, and 11) with suitable ADME-T profiles and promising bioavailability were selected. The mechanistic studies in dynamic mode further endorsed the potential of identified hits in blocking the ATP-binding site of the receptor with higher binding affinities than the native inhibitor, alpelisib (BYL-719), particularly the compounds 1, 2, and 11. These outcomes support the reliability of the developed classification model and the devised computational strategy for identifying new isoform-selective drug candidates for PI3Kα inhibition.

A susceptibility gene signature for ERBB2-driven mammary tumour development and metastasis in collaborative cross mice

BACKGROUND

Deeper insights into ERBB2-driven cancers are essential to develop new treatment approaches for ERBB2+ breast cancers (BCs). We employed the Collaborative Cross (CC) mouse model to unearth genetic factors underpinning Erbb2-driven mammary tumour development and metastasis.

METHODS

732 F1 hybrid female mice between FVB/N MMTV-Erbb2 and 30 CC strains were monitored for mammary tumour phenotypes. GWAS pinpointed SNPs that influence various tumour phenotypes. Multivariate analyses and models were used to construct the polygenic score and to develop a mouse tumour susceptibility gene signature (mTSGS), where the corresponding human ortholog was identified and designated as hTSGS. The importance and clinical value of hTSGS in human BC was evaluated using public datasets, encompassing TCGA, METABRIC, GSE96058, and I-SPY2 cohorts. The predictive power of mTSGS for response to chemotherapy was validated in vivo using genetically diverse MMTV-Erbb2 mice.

FINDINGS

Distinct variances in tumour onset, multiplicity, and metastatic patterns were observed in F1-hybrid female mice between FVB/N MMTV-Erbb2 and 30 CC strains. Besides lung metastasis, liver and kidney metastases emerged in specific CC strains. GWAS identified specific SNPs significantly associated with tumour onset, multiplicity, lung metastasis, and liver metastasis. Multivariate analyses flagged SNPs in 20 genes (Stx6, Ramp1, Traf3ip1, Nckap5, Pfkfb2, Trmt1l, Rprd1b, Rer1, Sepsecs, Rhobtb1, Tsen15, Abcc3, Arid5b, Tnr, Dock2, Tti1, Fam81a, Oxr1, Plxna2, and Tbc1d31) independently tied to various tumour characteristics, designated as a mTSGS. hTSGS scores (hTSGSS) based on their transcriptional level showed prognostic values, superseding clinical factors and PAM50 subtype across multiple human BC cohorts, and predicted pathological complete response independent of and superior to MammaPrint score in I-SPY2 study. The power of mTSGS score for predicting chemotherapy response was further validated in an in vivo mouse MMTV-Erbb2 model, showing that, like findings in human patients, mouse tumours with low mTSGS scores were most likely to respond to treatment.

INTERPRETATION

Our investigation has unveiled many new genes predisposing individuals to ERBB2-driven cancer. Translational findings indicate that hTSGS holds promise as a biomarker for refining treatment strategies for patients with BC.

FUNDING

The U.S. Department of Defense (DoD) Breast Cancer Research Program (BCRP) (BC190820), United States; MCIN/AEI/10.13039/501100011039 (PID2020-118527RB-I00, PDC2021-121735-I00), the "European Union Next Generation EU/PRTR," the Regional Government of Castile and León (CSI144P20), European Union.

Navigating the complexity of PI3K/AKT pathway in HER-2 negative breast cancer: biomarkers and beyond

The results of the SOLAR-1 and CAPItello-291, highlight the benefit of the ɑ-selective phosphoinositide 3-Kinase Pathway inhibitor (PI3Ki) alpelisib and the AKT inhibitor (AKTi) capivasertib in patients with hormone receptor-positive (HR+)/Human Epidermal Growth Factor Receptor 2 (HER2)- negative metastatic breast cancer (mBC) that have PIK3CA/AKT1/PTEN tumour alterations. Although effective, these drugs are associated with significant toxicities, which often limit their use, particularly in frail patients. Following the recent incorporation of these agents into clinical practice, and with many others currently in development, significant challenges have emerged, particularly those regarding biomarkers for patient selection. This review will discuss biomarkers of response and their resistance to PI3K/AKT inhibitors (PI3K/AKTis) in HR+/HER- BC in early and advanced settings to ascertain which populations will most benefit from these drugs. Of the biomarkers that were analysed, such as PIK3CA, AKT, PTEN mutations, insulin levels, 18 F-FDG-PET/TC, only the PIK3CA-mutations (PIK3CA-mut) and the AKT pathway alterations seem to have a predictive value for treatments with alpelisib and capivasertib. However, due to the retrospective and exploratory nature of the study, the data did not provide conclusive results. In addition, the different methods used to detect PIK3CA/AKT1/PTEN alterations underline the fact that the optimal diagnostic companion has yet to be established. We have summarised the clinical data on the approved and discontinued agents targeting this pathway and have assessed the drugs development, successes, and failures. Finally, because of tumour heterogeneity, we emphasise the importance of reassessing the mutational status of PI3KCA in both metastatic tissue and blood at the time of disease progression to better tailor treatment for patients.

Cryo-EM structures reveal two allosteric inhibition modes of PI3KαH1047R involving a re-shaping of the activation loop

PI3Kα is a lipid kinase that phosphorylates PIP2 and generates PIP3. The hyperactive PI3Kα mutation, H1047R, accounts for about 14% of breast cancer, making it a highly attractive target for drug discovery. Here, we report the cryo-EM structures of PI3KαH1047R bound to two different allosteric inhibitors QR-7909 and QR-8557 at a global resolution of 2.7 Å and 3.0 Å, respectively. The structures reveal two distinct binding pockets on the opposite sides of the activation loop. Structural and MD simulation analyses show that the allosteric binding of QR-7909 and QR-8557 inhibit PI3KαH1047R hyper-activity by reducing the fluctuation and mobility of the activation loop. Our work provides a strong rational basis for a further optimization and development of highly selective drug candidates to treat PI3KαH1047R-driven cancers.

Selective PI3Kδ inhibitor TYM-3-98 suppresses AKT/mTOR/SREBP1-mediated lipogenesis and promotes ferroptosis in KRAS-mutant colorectal cancer

Colorectal cancer (CRC) is one of the most common tumors of the digestive system worldwide. KRAS mutations limit the use of anti-EGFR antibodies in combination with chemotherapy for the treatment of CRC. Therefore, novel targeted therapies are needed to overcome the KRAS-induced oncogenesis. Recent evidence suggests that inhibition of PI3K led to ferroptosis, a nonapoptotic cell death closely related to KRAS-mutant cells. Here, we showed that a selective PI3Kδ inhibitor TYM-3-98 can suppress the AKT/mTOR signaling and activate the ferroptosis pathway in KRAS-mutant CRC cells in a concentration-dependent manner. This was evidenced by the lipid peroxidation, iron accumulation, and depletion of GSH. Moreover, the overexpression of the sterol regulatory element-binding protein 1 (SREBP1), a downstream transcription factor regulating lipid metabolism, conferred CRC cells greater resistance to ferroptosis induced by TYM-3-98. In addition, the effect of TYM-3-98 was confirmed in a xenograft mouse model, which demonstrated significant tumor suppression without obvious hepatoxicity or renal toxicity. Taken together, our work demonstrated that the induction of ferroptosis contributed to the PI3Kδ inhibitor-induced cell death via the suppression of AKT/mTOR/SREBP1-mediated lipogenesis, thus displaying a promising therapeutic effect of TYM-3-98 in CRC treatment.

Characterizing multi-PIK3CA mutations across cancer types: Toward precision oncology

BACKGROUND

PIK3CA mutations are implicated in various cancers, but the implications of multiple concurrent mutations and their orientations within the gene have not been fully explored.

METHODS

In this study, we analyzed multi-PIK3CA mutations across a diverse pan-cancer cohort comprising 3564 tumors.

RESULTS

Multi-PIK3CA mutations were present in 10.3% of all PIK3CA-mutant tumors, predominantly occurring in breast and gynecological cancers. Notably, mutations within the helical domain (E542:E545) exclusively occurred in the trans-orientation, contrasting with mutations in the kinase ABD and C2 domains, which mainly appeared in the cis orientation.

CONCLUSIONS

The distinct pattern of mutation orientations in PIK3CA suggests variable oncogenic potential, with helical domain mutations in the trans-orientation potentially being less oncogenic. These findings highlight the importance of mutation orientation in the PIK3CA gene as potential biomarkers for targeted therapy. This understanding is crucial for designing clinical trials that leverage PI3K inhibitors, aiming for more effective and precise cancer treatment.

The PI3K signaling pathway; from normal lymphopoiesis to lymphoid malignancies

INTRODUCTION

As a vital mechanism of survival, lymphopoiesis requires the collaboration of different signaling molecules to orchestrate each step of cell development and maturation. The PI3K pathway is considerably involved in the maturation of lymphatic cells and therefore, its dysregulation can immensely affect human well-being and cause some of the most prevalent malignancies. As a result, studies that investigate this pathway could pave the way for a better understanding of the lymphopoiesis mechanisms, the undesired changes that lead to cancer progression, and how to design drugs to solve this issue.

AREAS COVERED

The present review addresses the aforementioned aspects of the PI3K pathway and helps pave the way for future therapeutic approaches. In order to access the articles, databases such as Medicine Medline/PubMed, Scopus, Google Scholar, and Science Direct were utilized. The search formula was established by identifying main keywords including PI3K/Akt/mTOR pathway, Lymphopoiesis, Lymphoid malignancies, and inhibitors.

EXPERT OPINION

The PI3K pathway is crucial for lymphocyte development and differentiation, making it a potential target for therapeutic intervention in lymphoid cancers. Studies are focused on developing PI3K inhibitors to impede the progression of hematologic malignancies, highlighting the pathway's significance in lymphoma and lymphoid leukemia.

Beyond Anti-PD-1/PD-L1: Improving Immune Checkpoint Inhibitor Responses in Triple-Negative Breast Cancer

The introduction of anti-programmed cell death protein-1 (anti-PD-1) to the clinical management of triple-negative breast cancer (TNBC) represents a breakthrough for a disease whose treatment has long relied on the standards of chemotherapy and surgery. Nevertheless, few TNBC patients achieve a durable remission in response to anti-PD-1, and there is a need to develop strategies to maximize the potential benefit of immune checkpoint inhibition (ICI) for TNBC patients. In the present review, we discuss three conceptual strategies to improve ICI response rates in TNBC patients. The first effort involves improving patient selection. We discuss proposed biomarkers of response and resistance to anti-PD-1, concluding that an optimal biomarker will likely be multifaceted. The second effort involves identifying existing targeted therapies or chemotherapies that may synergize with ICI. In particular, we describe recent efforts to use inhibitors of the PI3K/AKT or RAS/MAPK/ERK pathways in combination with ICI. Third, considering the possibility that targeting the PD-1 axis is not the most promising strategy for TNBC treatment, we describe ongoing efforts to identify novel immunotherapy strategies.

Gedatolisib shows superior potency and efficacy versus single-node PI3K/AKT/mTOR inhibitors in breast cancer models

The PI3K, AKT, and mTOR (PAM) pathway is frequently dysregulated in breast cancer (BC) to accommodate high catabolic and anabolic activities driving tumor growth. Current therapeutic options for patients with hormone receptor (HR) + / HER2- advanced BC (ABC) include PAM inhibitors that selectively inhibit only one PAM pathway node, which can lead to drug resistance as cells rapidly adapt to maintain viability. We hypothesized that gedatolisib, which potently inhibits all Class I PI3K isoforms, as well as mTORC1 and mTORC2, may be more effective in BC cells than single-node PAM inhibitors by limiting adaptive resistances. By using multiple functional assays, a panel of BC cell lines was evaluated for their sensitivity to four different PAM inhibitors: gedatolisib (pan-PI3K/mTOR inhibitor), alpelisib (PI3Kα inhibitor), capivasertib (AKT inhibitor), and everolimus (mTORC1 inhibitor). Gedatolisib exhibited more potent and efficacious anti-proliferative and cytotoxic effects regardless of the PAM pathway mutational status of the cell lines compared to the single-node PAM inhibitors. The higher efficacy of gedatolisib was confirmed in three-dimensional culture and in BC PDX models. Mechanistically, gedatolisib decreased cell survival, DNA replication, cell migration and invasion, protein synthesis, glucose consumption, lactate production, and oxygen consumption more effectively than the other PAM inhibitors tested. These results indicate that inhibition of multiple PAM pathway nodes by a pan-PI3K/mTOR inhibitor like gedatolisib may be more effective at inducing anti-tumor activity than single-node PAM inhibitors. A global Phase 3 study is currently evaluating gedatolisib plus fulvestrant with and without palbociclib in patients with HR+/HER2- ABC.

Targeting PI3K/AKT/mTOR signaling to overcome drug resistance in cancer

This review comprehensively explores the challenge of drug resistance in cancer by focusing on the pivotal PI3K/AKT/mTOR pathway, elucidating its role in oncogenesis and resistance mechanisms across various cancer types. It meticulously examines the diverse mechanisms underlying resistance, including genetic mutations, feedback loops, and microenvironmental factors, while also discussing the associated resistance patterns. Evaluating current therapeutic strategies targeting this pathway, the article highlights the hurdles encountered in drug development and clinical trials. Innovative approaches to overcome resistance, such as combination therapies and precision medicine, are critically analyzed, alongside discussions on emerging therapies like immunotherapy and molecularly targeted agents. Overall, this comprehensive review not only sheds light on the complexities of resistance in cancer but also provides a roadmap for advancing cancer treatment.

Landscape of Endometrial Cancer: Molecular Mechanisms, Biomarkers, and Target Therapy

Endometrial cancer is one the most prevalent gynecological cancers and, unfortunately, has a poor prognosis due to low response rates to traditional treatments. However, the progress in molecular biology and understanding the genetic mechanisms involved in tumor processes offers valuable information that has led to the current classification that describes four molecular subtypes of endometrial cancer. This review focuses on the molecular mechanisms involved in the pathogenesis of endometrial cancers, such as genetic mutations, defects in the DNA mismatch repair pathway, epigenetic changes, or dysregulation in angiogenic or hormonal signaling pathways. The preclinical genomic and molecular investigations presented allowed for the identification of some molecules that could be used as biomarkers to diagnose, predict, and monitor the progression of endometrial cancer. Besides the therapies known in clinical practice, targeted therapy is described as a new cancer treatment that involves identifying specific molecular targets in tumor cells. By selectively inhibiting these targets, key signaling pathways involved in cancer progression can be disrupted while normal cells are protected. The connection between molecular biomarkers and targeted therapy is vital in the fight against cancer. Ongoing research and clinical trials are exploring the use of standard therapy agents in combination with other treatment strategies like immunotherapy and anti-angiogenesis therapy to improve outcomes and personalize treatment for patients with endometrial cancer. This approach has the potential to transform the management of cancer patients. In conclusion, enhancing molecular tools is essential for stratifying the risk and guiding surgery, adjuvant therapy, and cancer treatment for women with endometrial cancer. In addition, the information from this review may have an essential value in the personalized therapy approach for endometrial cancer to improve the patient's life.

Hydroxychloroquine interaction with phosphoinositide 3-kinase modulates prostate cancer growth in bone microenvironment: In vitro and molecular dynamics based approach

Patients with advanced prostate cancer (PCa) are more likely to develop bone metastases. Tumor cells thrive in the bone microenvironment, interacting with osteoblasts and osteoclasts. Given the PI3K/AKT pathway's metastatic potential and signal integration's ability to modulate cell fates in PCa development, drugs targeting this system have great therapeutic promise. Hydroxychloroquine (HCQ) is an anti-malarial medication commonly used to treat clinical conditions such as rheumatology and infectious disorders. We explored the anti-neoplastic effect of HCQ on PC3 and C4-2B cell lines in the bone microenvironment. Interestingly, HCQ treatment substantially decreases the viability, proliferation, and migration potential of PCa cells in the bone microenvironment. HCQ induces apoptosis and cell cycle arrest, even in the presence of osteoblast-secreted factors. Mechanistically, HCQ inhibited the activity of the PI3K/AKT signaling pathway, which ultimately regulates the proliferation and migration of PCa cells in the bone. The binding energy for docking HCQ with PI3K was -6.7 kcal/mol, and the complex was stabilized by hydrogen bonds, hydrophobic forces, and van der Waals forces. Molecular simulations further validated the structural integrity of the HCQ-PI3K complex without altering PI3K's secondary structure. Our findings underscore the efficacy of HCQ as a potential therapeutic agent in treating PCa.

Integrated mutational landscape analysis of poorly differentiated high-grade neuroendocrine carcinoma of the uterine cervix

High-grade neuroendocrine cervical cancers (NETc) are exceedingly rare, highly aggressive tumors. We analyzed 64 NETc tumor samples by whole-exome sequencing (WES). Human papillomavirus DNA was detected in 65.6% (42/64) of the tumors. Recurrent mutations were identified in PIK3CA, KMT2D/MLL2, K-RAS, ARID1A, NOTCH2, and RPL10. The top mutated genes included RB1, ARID1A, PTEN, KMT2D/MLL2, and WDFY3, a gene not yet implicated in NETc. Somatic CNV analysis identified two copy number gains (3q27.1 and 19q13.12) and five copy number losses (1p36.21/5q31.3/6p22.2/9q21.11/11p15.5). Also, gene fusions affecting the ACLY-CRHR1 and PVT1-MYC genes were identified in one of the eight samples subjected to RNA sequencing. To resolve evolutionary history, multiregion WES in NETc admixed with adenocarcinoma cells was performed (i.e., mixed-NETc). Phylogenetic analysis of mixed-NETc demonstrated that adenocarcinoma and neuroendocrine elements derive from a common precursor with mutations typical of adenocarcinomas. Over one-third (22/64) of NETc demonstrated a mutator phenotype of C > T at CpG consistent with deficiencies in MBD4, a member of the base excision repair (BER) pathway. Mutations in the PI3K/AMPK pathways were identified in 49/64 samples. We used two patient-derived-xenografts (PDX) (i.e., NET19 and NET21) to evaluate the activity of pan-HER (afatinib), PIK3CA (copanlisib), and ATR (elimusertib) inhibitors, alone and in combination. PDXs harboring alterations in the ERBB2/PI3K/AKT/mTOR/ATR pathway were sensitive to afatinib, copanlisib, and elimusertib (P < 0.001 vs. controls). However, combinations of copanlisib/afatinib and copanlisib/elimusertib were significantly more effective in controlling NETc tumor growth. These findings define the genetic landscape of NETc and suggest that a large subset of these highly lethal malignancies might benefit from existing targeted therapies.

The Role of Curcumin in Cancer: A Focus on the PI3K/Akt Pathway

Cancer is a life-threatening disease and one of the leading causes of death worldwide. Despite significant advancements in therapeutic options, most available anti-cancer agents have limited efficacy. In this context, natural compounds with diverse chemical structures have been investigated for their multimodal anti-cancer properties. Curcumin is a polyphenol isolated from the rhizomes of Curcuma longa and has been widely studied for its anti-inflammatory, anti-oxidant, and anti-cancer effects. Curcumin acts on the regulation of different aspects of cancer development, including initiation, metastasis, angiogenesis, and progression. The phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT) pathway is a key target in cancer therapy, since it is implicated in initiation, proliferation, and cancer cell survival. Curcumin has been found to inhibit the PI3K/Akt pathway in tumor cells, primarily via the regulation of different key mediators, including growth factors, protein kinases, and cytokines. This review presents the therapeutic potential of curcumin in different malignancies, such as glioblastoma, prostate and breast cancer, and head and neck cancers, through the targeting of the PI3K/Akt signaling pathway.

Unraveling molecular signatures in rare bone tumors and navigating the cancer pathway landscapes for targeted therapeutics

Rare cancers (RCs), which account for over 20% of cancer cases, face significant research and treatment challenges due to their limited prevalence. This results in suboptimal outcomes compared to more common malignancies. Rare bone tumors (RBTs) constitute 5-10% of rare cancer cases and pose unique diagnostic complexities. The therapeutic potential of anti-cancer drugs for RBTs remains largely unexplored. Identifying molecular alterations in cancer-related genes and their associated pathways is essential for precision medicine in RBTs. Small molecule inhibitors and monoclonal antibodies targeting specific RBT-associated proteins show promise. Ongoing clinical trials aim to define RBT biomarkers, subtypes, and optimal treatment contexts, including combination therapies and immunotherapeutic agents. This review addresses the challenges in diagnosing, treating, and studying RBTs, shedding light on the current state of RBT biomarkers, potential therapeutic targets, and promising inhibitors. Rare cancers demand attention and innovative solutions to improve clinical outcomes.

A novel pan-PI3K inhibitor KTC1101 synergizes with anti-PD-1 therapy by targeting tumor suppression and immune activation

BACKGROUND

Phosphoinositide 3-kinases (PI3Ks) are critical regulators of diverse cellular functions and have emerged as promising targets in cancer therapy. Despite significant progress, existing PI3K inhibitors encounter various challenges such as suboptimal bioavailability, potential off-target effects, restricted therapeutic indices, and cancer-acquired resistance. Hence, novel inhibitors that overcome some of these challenges are needed. Here, we describe the characterization of KTC1101, a novel pan-PI3K inhibitor that simultaneously targets tumor cell proliferation and the tumor microenvironment. Our studies demonstrate that KTC1101 significantly increases the anti-PD-1 efficacy in multiple pre-clinical mouse models.

METHODS

KTC1101 was synthesized and characterized employing chemical synthesis, molecular modeling, Nuclear Magnetic Resonance (NMR), and mass spectrometry. Its target specificity was confirmed through the kinase assay, JFCR39 COMPARE analysis, and RNA-Seq analysis. Metabolic stability was verified via liver microsome and plasma assays, pharmacokinetics determined by LC-MS/MS, and safety profile established through acute toxicity assays to determine the LD50. The antiproliferative effects of KTC1101 were evaluated in a panel of cancer cell lines and further validated in diverse BALB/c nude mouse xenograft, NSG mouse xenograft and syngeneic mouse models. The KTC1101 treatment effect on the immune response was assessed through comprehensive RNA-Seq, flow cytometry, and immunohistochemistry, with molecular pathways investigated via Western blot, ELISA, and qRT-PCR.

RESULTS

KTC1101 demonstrated strong inhibition of cancer cell growth in vitro and significantly impeded tumor progression in vivo. It effectively modulated the Tumor Microenvironment (TME), characterized by increased infiltration of CD8+ T cells and innate immune cells. An intermittent dosing regimen of KTC1101 enhanced these effects. Notably, KTC1101 synergized with anti-PD-1 therapy, significantly boosting antitumor immunity and extending survival in preclinical models.

CONCLUSION

KTC1101's dual mechanism of action-directly inhibiting tumor cell growth and dynamically enhancing the immune response- represents a significant advancement in cancer treatment strategies. These findings support incorporating KTC1101 into future oncologic regimens to improve the efficacy of immunotherapy combinations.

The application of nanoparticles-based ferroptosis, pyroptosis and autophagy in cancer immunotherapy

Immune checkpoint blockers (ICBs) have been applied for cancer therapy and achieved great success in the field of cancer immunotherapy. Nevertheless, the broad application of ICBs is limited by the low response rate. To address this issue, increasing studies have found that the induction of immunogenic cell death (ICD) in tumor cells is becoming an emerging therapeutic strategy in cancer treatment, not only straightly killing tumor cells but also enhancing dying cells immunogenicity and activating antitumor immunity. ICD is a generic term representing different cell death modes containing ferroptosis, pyroptosis, autophagy and apoptosis. Traditional chemotherapeutic agents usually inhibit tumor growth based on the apoptotic ICD, but most tumor cells are resistant to the apoptosis. Thus, the induction of non-apoptotic ICD is considered to be a more efficient approach for cancer therapy. In addition, due to the ineffective localization of ICD inducers, various types of nanomaterials have been being developed to achieve targeted delivery of therapeutic agents and improved immunotherapeutic efficiency. In this review, we briefly outline molecular mechanisms of ferroptosis, pyroptosis and autophagy, as well as their reciprocal interactions with antitumor immunity, and then summarize the current progress of ICD-induced nanoparticles based on different strategies and illustrate their applications in the cancer therapy.

NF-κB in biology and targeted therapy: new insights and translational implications

NF-κB signaling has been discovered for nearly 40 years. Initially, NF-κB signaling was identified as a pivotal pathway in mediating inflammatory responses. However, with extensive and in-depth investigations, researchers have discovered that its role can be expanded to a variety of signaling mechanisms, biological processes, human diseases, and treatment options. In this review, we first scrutinize the research process of NF-κB signaling, and summarize the composition, activation, and regulatory mechanism of NF-κB signaling. We investigate the interaction of NF-κB signaling with other important pathways, including PI3K/AKT, MAPK, JAK-STAT, TGF-β, Wnt, Notch, Hedgehog, and TLR signaling. The physiological and pathological states of NF-κB signaling, as well as its intricate involvement in inflammation, immune regulation, and tumor microenvironment, are also explicated. Additionally, we illustrate how NF-κB signaling is involved in a variety of human diseases, including cancers, inflammatory and autoimmune diseases, cardiovascular diseases, metabolic diseases, neurological diseases, and COVID-19. Further, we discuss the therapeutic approaches targeting NF-κB signaling, including IKK inhibitors, monoclonal antibodies, proteasome inhibitors, nuclear translocation inhibitors, DNA binding inhibitors, TKIs, non-coding RNAs, immunotherapy, and CAR-T. Finally, we provide an outlook for research in the field of NF-κB signaling. We hope to present a stereoscopic, comprehensive NF-κB signaling that will inform future research and clinical practice.