Cellular function of phosphoinositide 3-kinases: implications for development, homeostasis, and cancer

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.

Sepsis and high-density lipoproteins: Pathophysiology and potential new therapeutic targets

In 2020, sepsis has been defined a worldwide health major issue (World Health Organization). Lung, urinary tract and abdominal cavity are the preferred sites of sepsis-linked infection. Research has highlighted that the advancement of sepsis is not only related to the presence of inflammation or microbial or host pattern recognition. Clinicians and researchers now recognized that a severe immunosuppression is also a common feature found in patients with sepsis, increasing the susceptibility to secondary infections. Lipopolysaccharides (LPS) are expressed on the cell surface of Gram-negative, whereas Gram-positive bacteria express peptidoglycan (PGN) and lipoteichoic acid (LTA). The main mechanism by which LPS trigger host innate immune responses is binding to TLR4-MD2 (toll-like receptor4-myeloid differentiation factor 2), whereas, PGN and LTA are exogenous ligands of TLR2. Nucleotide-binding oligomerization domain (NOD)-like receptors are the most well-characterized cytosolic pattern recognition receptors, which bind microbial molecules, endogenous by-products and environmental triggers. It has been demonstrated that high-density lipoproteins (HDL), besides their major role in promoting cholesterol efflux, possess diverse pleiotropic properties, ranging from a modulation of the immune system to anti-inflammatory, anti-apoptotic, and anti-oxidant functions. In addition, HDL are able at i) binding LPS, preventing the activating of TLR4, and ii) inducing the expression of ATF3 (Activating transcription factor 3), a negative regulator of the TLR signalling pathways, contributing at justifying their capacity to hamper infection-based illnesses. Therefore, reconstituted HDL (rHDL), constituted by apolipoprotein A-I/apolipoprotein A-IMilano complexed with phospholipids, may be considered as a new therapeutic tool for the management of sepsis.

Exploring a kinase inhibitor targeting PI3KCA mutant cancer cells

The PI3K/mTOR signaling pathway is often disrupted in human cancers, with PI3Kα being one of the most mutated kinases. There has been considerable interest in developing small-molecule inhibitors aimed at blocking the mutant PI3Kα-driven phosphatidylinositol 3-kinase (PI3K) signaling pathway as a potential treatment for cancer. In this study, we describe our effort to identify a compound, phenylacetamide-1H-imidazol-5-one (KIM-161), from our in-house oncogenic kinase-targeting inhibitors. KIM-161 showed excellent anti-proliferative activities at sub-nanomolar concentrations, primarily against mutant PI3Kα breast cancer cell lines, when compared with wild-type PI3Kα breast cancer cell lines, producing both dose- and time-dependent effects with an IC50 range of 1.42 - 0.064 µM. Next, we observed that KIM-161 was able to induce ROS production by modulating breast cancer metabolism, suggesting its broad effects on mutant PI3Kα regulated downstream pathways. We also computationally analyzed the binding interactions between KIM-161 and PI3K-alpha (PDB ID: 8EXL). Molecular docking showed that KIM-161 had a docking score of -7.44 Kcal/mol, compared to the reference compound, which had a docking score of -7.67 Kcal/mol. Moreover, molecular dynamics simulation studies demonstrated that the PI3Ka-KIM-161 complex remained stable throughout the 100 ns simulation, when compared to the PI3Ka complex with the co-crystallized inhibitor. These findings present KIM-161 as a promising lead, providing valuable insights into treatment approaches and resistance mechanisms associated with PI3K inhibitors in specific PIK3CA-mutant cancer subtypes.

Ubiquitous expression of an activating mutation in the Pik3ca gene reprograms glucose and lipid metabolism in mice

Mutations in PIK3CA, the gene encoding the p110α catalytic subunit of PI3K, are among the most common mutations in human cancers and overgrowth syndromes. The ubiquitous expression of the activating Pik3caH1047R mutation results in reduced survival, organomegaly, hypoglycaemia and hypoinsulinemia in mice. Here we demonstrate that in vivo expression of Pik3caH1047R attenuates the rise in blood glucose in response to oral glucose administration, stimulates glucose uptake in peripheral tissues, inhibits hepatic gluconeogenesis and pancreatic insulin secretion, and increases adipose lipolysis and white adipose tissue browning. Together, our data reveal that the systemic activation of the PI3K pathway in mice disrupts glucose homeostasis through the regulation of hepatic gluconeogenesis, and leads to increased lipolysis of adipose tissue.

Regulatory Effect of Atorvastatin combined with Berberine on PI3K/Akt/FoxO1 Signaling Pathway in Rats with Hyperlipidemia

1.Atorvastatin Calcium (AC) is the first line lipid-lowering drug in clinical. Nowadays, the combination of AC and BBR is often used to treat hyperlipidemia in clinical. In order to determine the mechanism, we investigate the regulatory of atorvastatin combined with berberine on PI3K/Akt/FoxO1 signaling pathway in rats with hyperlipidemia.2.The hyperlipidemia rat model was constructed. Meanwhile, lipid-lowering and liver protective effects were determined by oil red O and H&E method. The expression of PI3K, Akt and FoxO1 was examined by IHC, WB and RT-pCR. The level of CK and LDH in serum was examined by ELISA.3.The results showed that the expression of PI3K, AKT increased and FoxO1 decreased in MC group compared with NC group (P < 0.01). The expression of PI3K, AKT decreased and FoxO1 increased compared with MC group (P < 0.05). The expression of FoxO1 in combination group is lower than AC group. The levels of CK and LDH in AC group increased compared with NC group (P < 0.01), but decreased significantly in AC + BBR group compared with AC group(P < 0.01).4.The combination of AC and BBR could regulate the lipid level by mediating PI3K/Akt/FoxO1, which providing a new references for the treatment of hyperlipidemia.

Role of the Wnt signaling pathway in the complex microenvironment of breast cancer and prospects for therapeutic potential (Review)

The focus on breast cancer treatment has shifted from the cytotoxic effects of single drugs on tumor cells to multidimensional multi‑pathway synergistic intervention strategies targeting the tumor microenvironment (TME). The activation of the Wnt signaling pathway in the TME of breast cancer cells serves a key regulatory role in tissue homeostasis and is a key driver of the carcinogenic process. Modulating the crosstalk between the Wnt pathway and TME of breast cancer is key for understanding the biological behavior of breast cancer and advancing the development of novel antitumor drugs. The present review aimed to summarize the complex mechanisms of the Wnt signaling pathway in the breast cancer TME, interactions between the Wnt signaling pathway and components of the breast cancer TME and breast cancer‑associated genes, as well as the interactions between the Wnt signaling pathway and other signaling cascades at the molecular level. Furthermore, the present review aimed to highlight the unique advantages of the Wnt signaling pathway in the macro‑regulation of the TME and the current therapeutic strategies targeting the Wnt signaling pathway, their potential clinical value and future research directions in breast cancer treatment.

Lysosomal PIP3 revealed by genetically encoded lipid biosensors

3-Phosphoinositides (3-PIs), phosphatidylinositol (3,4) bisphosphate [PI(3,4)P2] and phosphatidylinositol (3,4,5) trisphosphate (PIP3), are important lipid second messengers in the Phosphoinositide 3-Kinase (PI3K)/Akt signaling pathway, which is crucial to cell growth and frequently dysregulated in cancer. Emerging evidence suggests these lipid second messengers may be present in membranes beyond the plasma membrane, yet their spatial regulation within other membrane compartments is not well understood. To dissect the spatial regulation of specific 3-PI species, we developed genetically encodable biosensors with selectivity for PIP3 or PI(3,4)P2. Using these biosensors, we showed that PIP3 significantly accumulated at the lysosome upon growth factor stimulation, in contrast to the conventional view that PIP3 is exclusively present in the plasma membrane. Furthermore, we showed that lysosomal PIP3 originates from the plasma membrane and relies on dynamin-dependent endocytosis for lipid internalization. Thus, PIP3 can exploit dynamic trafficking pathways to access subcellular compartments and regulate signaling in a spatially selective manner.

Mutation Analysis of TMB-High Colorectal Cancer: Insights Into Molecular Pathways and Clinical Implications

Colorectal cancer (CRC) is well characterized in terms of genetic mutations and the mechanisms by which they contribute to carcinogenesis. Mutations in APC, TP53, and KRAS are common in CRC, indicating key roles for these genes in tumor development and progression. However, for certain tumors with low frequencies of these mutations that are defined by tumor location and molecular phenotypes, a carcinogenic mechanism dependent on BRAF mutations has been proposed. We here analyzed targeted sequence data linked to clinical information for CRC, focusing on tumors with a high tumor mutation burden (TMB) in order to identify the characteristics of associated mutations, their relations to clinical features, and the mechanisms of carcinogenesis in tumors lacking the major driver oncogenes. Analysis of overall mutation frequencies confirmed that APC, TP53, and KRAS mutations were the most prevalent in our cohort. Compared with other tumors, TMB-high tumors were more frequent on the right side of the colon, had lower KRAS and higher BRAF mutation frequencies as well as a higher microsatellite instability (MSI) score, and showed a greater contribution of a mutational signature associated with MSI. Ranking of variant allele frequencies to identify genes that play a role early in carcinogenesis suggested that mutations in genes related to the DNA damage response (such as ATM and POLE) and to MSI (such as MSH2 and MSH6) may precede BRAF mutations associated with activation of the serrated pathway in TMB-high tumors. Our results thus indicate that TMB-high tumors suggest that mutations of genes related to mismatch repair and the DNA damage response may contribute to activation of the serrated pathway in CRC.

Unlocking the dual role of autophagy: A new strategy for treating lung cancer

Lung cancer exhibits the highest incidence and mortality rates among cancers globally, with a five-year overall survival rate alarmingly below 20%. Targeting autophagy, though a controversial therapeutic strategy, is extensively employed in clinical practice. Current research is actively pursuing various therapeutic strategies using small molecules to exploit the dual function of autophagy. Nevertheless, the pivotal question of enhancing or inhibiting autophagy in cancer therapy merits further attention. This review aims to provide a comprehensive overview of the mechanisms of autophagy in lung cancer. It also explores recent advances in targeting cytotoxic autophagy and inhibiting protective autophagy with small molecules to induce cell death in lung cancer cells. Notably, most autophagy-targeting drugs, primarily natural small molecules, have demonstrated that activating cytotoxic autophagy effectively induces cell death in lung cancer, as opposed to inhibiting protective autophagy. These insights contribute to identifying druggable targets and drug candidates for potential autophagy-related lung cancer therapies, offering promising approaches to combat this disease.

Nitroxidative Stress, Cell-Signaling Pathways, and Manganese Porphyrins: Therapeutic Potential in Neuropathic Pain

Neuropathic pain, a debilitating condition arising from somatosensory system damage, significantly impacts quality of life, leading to anxiety, self-mutilation, and depression. Oxidative and nitrosative stress, an imbalance between reactive oxygen and nitrogen species (ROS/RNS) and antioxidant defenses, plays a crucial role in its pathophysiology. While reactive species are essential for physiological functions, excessive levels can cause cellular component damage, leading to neuronal dysfunction and pain. This review highlights the complex interactions between reactive species, antioxidant systems, cell signaling, and neuropathic pain. We discuss the physiological roles of ROS/RNS and the detrimental effects of oxidative and nitrosative stress. Furthermore, we explore the potential of manganese porphyrins, compounds with antioxidant properties, as promising therapeutic agents to mitigate oxidative stress and alleviate neuropathic pain by targeting key cellular pathways involved in pain. Further research is needed to fully understand their therapeutic potential in managing neuropathic pain in human and non-human animals.

Therapeutic strategies and landscape of metaplastic breast cancer

Metaplastic breast cancer is a rare and heterogeneous subtype of breast cancer, associated with a poor prognosis. Its distinct biological behavior and morphological features contribute to resistance to standard treatment regimens. Hitherto, the optimal therapeutic strategy for metaplastic breast cancer remains underexplored. Herein, we review the literature on the treatment of metaplastic breast cancer, summarizing current local and systemic therapies, and discuss potential therapeutic targets and novel strategies based on its pathological and molecular characteristics. Targeted therapy and immunotherapy may provide more personalized treatment options, with the potential to improve the prognosis of this disease.

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.

Multi-omic markers of intraductal papillary mucinous neoplasms progression into pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is the most lethal and common form of pancreatic cancer, it has no specific symptoms, and most of the patients are diagnosed when the disease is already at an advanced stage. Chemotherapy typically has only a modest effect, making surgery the most effective treatment option. However, only a small percentage of patients are amenable to surgery. One viable strategy to reduce PDAC death burden associated with the disease is to focus on precursor lesions and identify markers able to predict who will evolve into PDAC. While most PDACs are believed to be preceded by pancreatic intraepithelial neoplasms (PanINs), 5-10 % arise from Intraductal papillary mucinous neoplasms (IPMNs), which are mass-forming cystic lesions that are very common in the general population. IPMNs offer an invaluable model of pancreatic carcinogenesis for researchers to analyse, as well as a target population for PDAC early detection by clinicians. The evolution of IPMN into cancer is a complex and multistep process, therefore the identification of individual markers will not be the solution. In recent years, multiple omics technologies have been instrumental to identify possible biomarkers of IPMN progression and carcinogenesis. The only foreseeable strategy will be to integrate multi-omics data, alongside clinical and morphological features, into a progression score or signature using either standard epidemiologic tools or artificial intelligence. The aim of this manuscript is to review the current knowledge on genetic biomarkers and to briefly mention also additional omics, such as metabolomics, the exposome, the miRNome and epigenomics of IPMNs.

Improved production of class I phosphatidylinositol 4,5-bisphosphate 3-kinase

Phosphatidylinositol 4,5-bisphosphate 3-kinases (PI3K) are a family of kinases whose activity affects pathways needed for basic cell functions. As a result, PI3K is one of the most mutated genes in all human cancers and serves as an ideal therapeutic target for cancer treatment. Expanding on work done by other groups we improved protein yield to produce stable and pure protein using a variety of modifications including improved solubility tag, novel expression modalities, and optimized purification protocol and buffer. By these means, we achieved a 40-fold increase in yield for p110α/p85α and a 3-fold increase in p110α. We also used these protocols to produce comparable constructs of the β and δ isoforms of PI3K. Increased yield enhanced the efficiency of our downstream high throughput drug discovery efforts on the PIK3 family of kinases.

Expression of toll-like receptors in recurrent pleomorphic adenoma and carcinoma ex pleomorphic adenoma

Pleomorphic adenoma (PA) is a benign salivary gland tumour that may recur or undergo malignant transformation (CXPA). Toll-like receptors (TLR) mediate immune responses triggered by various agents such as viruses and are related to tumour formation either by stimulating or suppressing their growth, with variation across different tumour entities. We compared TLR immunohistochemical expression in PA, its recurrent counterparts and CXPA and evaluated the effect of virus presence in these tumours. We studied the expression of TLR-2, -3, -5, -7 and -9 in 25 PA, 34 recurrent PA and 15 CXPA tumour samples. In addition, we examined the TLR expression levels in the presence and absence of herpes-, polyoma- and parvovirus DNA in a subset of tumours (n = 20). CXPA expressed significantly more TLR-5 and TLR-9 in the nucleus, cytoplasm and cell membrane compared with benign PA. The presence of virus DNA did not notably affect the TLR expression. TLR expression patterns seem to reflect tumour behaviour but are independent of the presence of viruses tested in this study.

The Role and Mechanism of TRIM Proteins in Gastric Cancer

Tripartite motif (TRIM) family proteins, distinguished by their N-terminal region that includes a Really Interesting New Gene (RING) domain with E3 ligase activity, two B-box domains, and a coiled-coil region, have been recognized as significant contributors in carcinogenesis, primarily via the ubiquitin-proteasome system (UPS) for degrading proteins. Mechanistically, these proteins modulate a variety of signaling pathways, including Wnt/β-catenin, PI3K/AKT, and TGF-β/Smad, contributing to cellular regulation, and also impact cellular activities through non-signaling mechanisms, including modulation of gene transcription, protein degradation, and stability via protein-protein interactions. Currently, growing evidence indicates that TRIM proteins emerge as potential regulators in gastric cancer, exhibiting both tumor-suppressive and oncogenic roles. Given their critical involvement in cellular processes and the notable challenges of gastric cancer, exploring the specific contributions of TRIM proteins to this disease is necessary. Consequently, this review elucidates the roles and mechanisms of TRIM proteins in gastric cancer, emphasizing their potential as therapeutic targets and prognostic factors.

The PIK3CA gene and its pivotal role in tumor tropism of triple-negative breast cancer

The PIK3CA gene is a linchpin in the intricate molecular network governing triple-negative breast cancer (TNBC) tumor tropism, serving as a focal point for understanding this aggressive disease. Anchored within the PI3K/AKT/mTOR signaling axis, PIK3CA mutations exert substantial influence, driving cellular processes that highlight the unique biology of TNBC. This review meticulously highlights the association between PIK3CA mutations and distinct TNBC subtypes, elucidating the gene's multifaceted contributions to tumor tropism. Molecular dissection reveals how PIK3CA mutations dynamically modulate chemokine responses, growth factor signaling, and extracellular matrix interactions, orchestrating the complex migratory behaviour characteristic of TNBC cells. A detailed exploration of PIK3CA-targeted strategies in the therapeutic arena is presented, outlining the current landscape of clinical trials and precision medicine approaches. As the scientific narrative converges, this review underscores the critical role of PIK3CA in shaping the molecular intricacies of TNBC tumor tropism and illuminates pathways toward tailored interventions, promising a paradigm shift in the clinical management of TNBC.

Sex-dimorphic effects of glucose transporter-2 gene knockdown on hypothalamic primary astrocyte phosphoinositide-3-kinase (PI3K)/protein kinase B (PKB/Akt)/mammalian target of rapamycin (mTOR) cascade protein expression and phosphorylation

Glucose transporter-2 (GLUT2), a unique high capacity/low affinity, highly efficient membrane transporter and sensor, regulates hypothalamic astrocyte glucose phosphorylation and glycogen metabolism. The phosphoinositide-3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway participates in glucose homeostasis, but its sensitivity to glucose-sensory cues is unknown. Current research used a hypothalamic astrocyte primary culture model to investigate whether glucoprivation causes PI3K/Akt/mTOR pathway activation in one or both sexes by GLUT2-dependent mechanisms. Glucoprivation did not alter astrocyte PI3K levels, yet up-regulated both phosphorylated derivatives in female and down-regulated male p60 phosphoprotein expression. GLUT2 siRNA pretreatment diminished glucoprivic patterns of PI3K and phospho-PI3K expression in each sex. Astrocyte Akt and phospho-Akt/Thr308 proteins exhibited divergent, sex-contingent responses to GLUT2 gene knockdown or glucoprivation. GLUT2 siRNA pretreatment exacerbated glucoprivic-associated Akt diminution in the female, and either amplified (male) or reversed (female) glucoprivic regulation of phospho-Akt/Thr308 expression. GLUT2 gene silencing down- (male) or up-(female) regulated mTOR protein, and phospho-mTOR protein in male. Male astrocyte mTOR and phospho-mTOR profile were refractory to glucoprivation, but glucose-deprived females showed GLUT2-independent mTOR inhibition and GLUT2-dependent phospho-mTOR up-augmentation. Results identify a larger number of glucoprivic-sensitive PI3K/Akt/mTOR pathway proteins in female versus male astrocytes, and document divergent responses of common glucose-sensitive targets. GLUT2 stimulates phosphoPI3K protein expression in each sex, but imposes differential control of PI3K, Akt, phospho-Akt/Thr308, mTOR, and phospho-mTOR profiles in male versus female. Data implicate GLUT2 as a driver of distinctive pathway protein responses to glucoprivation in female, but not male.

Design, synthesis, and biological evaluation of 2,4-dimorpholinopyrimidine-5-carbonitrile derivatives as orally bioavailable PI3K inhibitors

Introduction

Phosphoinositide-3-kinase (PI3K) is overexpressed in many tumors and is, thus, an ideal target for cancer treatments. Accordingly, there is an urgent need for the development of PI3K inhibitors with high potency and low toxicity.

Methods

In this study, we designed and synthesized a series of 2,4-dimorpholinopyrimidine-5-carbonitrile derivatives, which were evaluated for their PI3K inhibitory potency.

Results and discussion

Compound 17p demonstrated comparable PI3Kα inhibitory activity (IC50: 31.8 ± 4.1 nM) to the positive control, BKM-120 (IC50: 44.6 ± 3.6 nM). In addition, 17p showed significant inhibitory activity against PI3Kδ (IC50: 15.4 ± 1.9 nM) and significant isoform selectivity against PI3Kβ, PI3Kγ, and mTOR. Furthermore, 17p exhibited good antiproliferative activities against cancer cell activity and good safety in the Ames and hERG tests while having outstanding liver microsomal stability in vitro, with half-lives of 38.5 min in rats and 127.9 min in humans. In addition, in an apoptosis assay, 17p could induce dose-dependent cytotoxicity in the ovarian cancer cell line A2780. In a pharmacokinetic study, 17p was stable (T ½: 2.03 h) and showed high bioavailability (46.2%). Collectively, these results indicate that 17p could be a promising PI3K agent for cancer treatment.

Targeting the RAS upstream and downstream signaling pathway for cancer treatment

Cancer often involves the overactivation of RAS/RAF/MEK/ERK (MAPK) and PI3K-Akt-mTOR pathways due to mutations in genes like RAS, RAF, PTEN, and PIK3CA. Various strategies are employed to address the overactivation of these pathways, among which targeted therapy emerges as a promising approach. Directly targeting specific proteins, leads to encouraging results in cancer treatment. For instance, RTK inhibitors such as imatinib and afatinib selectively target these receptors, hindering ligand binding and reducing signaling initiation. These inhibitors have shown potent efficacy against Non-Small Cell Lung Cancer. Other inhibitors, like lonafarnib targeting Farnesyltransferase and GGTI 2418 targeting geranylgeranyl Transferase, disrupt post-translational modifications of proteins. Additionally, inhibition of proteins like SOS, SH2 domain, and Ras demonstrate promising anti-tumor activity both in vivo and in vitro. Targeting downstream components with RAF inhibitors such as vemurafenib, dabrafenib, and sorafenib, along with MEK inhibitors like trametinib and binimetinib, has shown promising outcomes in treating cancers with BRAF-V600E mutations, including myeloma, colorectal, and thyroid cancers. Furthermore, inhibitors of PI3K (e.g., apitolisib, copanlisib), AKT (e.g., ipatasertib, perifosine), and mTOR (e.g., sirolimus, temsirolimus) exhibit promising efficacy against various cancers such as Invasive Breast Cancer, Lymphoma, Neoplasms, and Hematological malignancies. This review offers an overview of small molecule inhibitors targeting specific proteins within the RAS upstream and downstream signaling pathways in cancer.

Targeting PI3K family with small-molecule inhibitors in cancer therapy: current clinical status and future directions

The Phosphatidylinositol-3-kinase (PI3K) family is well-known to comprise three classes of intracellular enzymes. Class I PI3Ks primarily function in signaling by responding to cell surface receptor stimulation, while class II and III are more involved in membrane transport. Under normal physiological conditions, the PI3K signaling network orchestrates cell growth, division, migration and survival. Aberrant activation of the PI3K signaling pathway disrupts cellular activity and metabolism, often marking the onset of cancer. Currently, the Food and Drug Administration (FDA) has approved the clinical use of five class I PI3K inhibitors. These small-molecule inhibitors, which exhibit varying selectivity for different class I PI3K family members, are primarily used in the treatment of breast cancer and hematologic malignancies. Therefore, the development of novel class I PI3K inhibitors has been a prominent research focus in the field of oncology, aiming to enhance potential therapeutic selectivity and effectiveness. In this review, we summarize the specific structures of PI3Ks and their functional roles in cancer progression. Additionally, we critically evaluate small molecule inhibitors that target class I PI3K, with a particular focus on their clinical applications in cancer treatment. Moreover, we aim to analyze therapeutic approaches for different types of cancers marked by aberrant PI3K activation and to identify potential molecular targets amenable to intervention with small-molecule inhibitors. Ultimately, we propose future directions for the development of therapeutic strategies that optimize cancer treatment outcomes by modulating the PI3K family.

The essential roles of lncRNAs/PI3K/AKT axis in gastrointestinal tumors

The role of long noncoding RNA (lncRNA) in tumors, particularly in gastrointestinal tumors, has gained significant attention. Accumulating evidence underscores the interaction between various lncRNAs and diverse molecular pathways involved in cancer progression. One such pivotal pathway is the PI3K/AKT pathway, which serves as a crucial intracellular mechanism maintaining the balance among various cellular physiological processes for normal cell growth and survival. Frequent dysregulation of the PI3K/AKT pathway in cancer, along with aberrant activation, plays a critical role in driving tumorigenesis. LncRNAs modulate the PI3K/AKT signaling pathway through diverse mechanisms, primarily by acting as competing endogenous RNA to regulate miRNA expression and associated genes. This interaction significantly influences fundamental biological behaviors such as cell proliferation, metastasis, and drug resistance. Abnormal expression of numerous lncRNAs in gastrointestinal tumors often correlates with clinical outcomes and pathological features in patients with cancer. Additionally, these lncRNAs influence the sensitivity of tumor cells to chemotherapy in multiple types of gastrointestinal tumors through the abnormal activation of the PI3K/AKT pathway. These findings provide valuable insights into the mechanisms underlying gastrointestinal tumors and potential therapeutic targets. However, gastrointestinal tumors remain a significant global health concern, with increasing incidence and mortality rates of gastrointestinal tumors over recent decades. This review provides a comprehensive summary of the latest research on the interactions of lncRNA and the PI3K/AKT pathway in gastrointestinal tumor development. Additionally, it focuses on the functions of lncRNAs and the PI3K/AKT pathway in carcinogenesis, exploring expression profiles, clinicopathological characteristics, interaction mechanisms with the PI3K/AKT pathway, and potential clinical applications.

Combined targeted therapy with PI3K and CDK4/6, or FGFR inhibitors show synergistic effects in a neuroblastoma spheroid culture model

AIM

Neuroblastoma (NB) is, in spite of current intensive therapy with severe side effects, still not cured so new therapies are needed. Recently, we showed combining phosphoinositide 3-kinase (PI3K) (BYL719), fibroblast growth factor receptor (FGFR) (JNJ-42756493) and cyclin-dependent kinase 4/6 (CDK4/6) (PD-0332991) inhibitors, in vitro in NB cell lines grown as monolayers had synergistic effects. However, there were variations depending on the combinations used and the targeted NB cell lines. To obtain further information and to mimic more natural circumstances, we investigated the effects of single and combined administrations of the above inhibitors in spheroid NB-cultures.

MATERIAL AND METHODS

Spheroid cultures of NB cell lines SK-N-AS, SK-N-BE(2)-C, SK-N-FI and SK-N-SH were established and treated with single and combined administrations of BYL719, JNJ-42756493, and PD-0332991 and followed for growth, viability, proliferation, cytotoxicity and migration.

KEY FINDINGS

Single inhibitor administrations gave dose dependent responses with regard to growth and viability and their combinations were efficient and resulted in a range of additive and synergistic effects. The responses to individual drugs and their various combinations were predominantly alike regardless of whether the cells were cultivated in monolayer or D spheroid NB models. However, in general, slightly higher drug concentrations were necessary in spheroidcultures.

SIGNIFICANCE

This study provides pre-clinical evidence that single PI3K, FGFR, and CDK4/6, inhibitors exhibit promising anti-NB activity and when combined lower doses of the drugs could be also used in spheroid NB-cultures, supporting the pursuit of further in vitro and in vivo studies in preparation for future potential clinical use.

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.

The interplay between the PI3K/AKT pathway and circadian clock in physiologic and cancer-related pathologic conditions

The circadian clock is responsible for the regulation of different cellular processes, and its disturbance has been linked to the development of different diseases, such as cancer. The main molecular mechanism for this issue has been linked to the crosstalk between core clock regulators and intracellular pathways responsible for cell survival. The PI3K/AKT signalling pathway is one of the most known intracellular pathways in the case of cancer initiation and progression. This pathway regulates different aspects of cell survival including proliferation, apoptosis, metabolism, and response to environmental stimuli. Accumulating evidence indicates that there is a link between the PI3K/AKT pathway activity and circadian rhythm in physiologic and cancer-related pathogenesis. Different classes of PI3Ks and AKT isoforms are involved in regulating circadian clock components in a transcriptional and functional manner. Reversely, core clock components induce a rhythmic fashion in PI3K and AKT activity in physiologic and pathogenic conditions. The aim of this review is to re-examine the interplay between this pathway and circadian clock components in normal condition and cancer pathogenesis, which provides a better understanding of how circadian rhythms may be involved in cancer progression.

Small molecule targeted therapies for endometrial cancer: progress, challenges, and opportunities

Endometrial cancer (EC) is a common malignancy among women worldwide, and its recurrence makes it a common cause of cancer-related death. Surgery and external radiation, chemotherapy, or a combination of strategies are the cornerstone of therapy for EC patients. However, adjuvant treatment strategies face certain drawbacks, such as resistance to chemotherapeutic drugs; therefore, it is imperative to explore innovative therapeutic strategies to improve the prognosis of EC. With the development of pathology and pathophysiology, several biological targets associated with EC have been identified, including PI3K/Akt/mTOR, PARP, GSK-3β, STAT-3, and VEGF. In this review, we summarize the progress of small molecule targeted therapies in terms of both basic research and clinical trials and provide cases of small molecules combined with fluorescence properties in the clinical applications of integrated diagnosis and treatment. We hope that this review will facilitate the further understanding of the regulatory mechanism governing the dysregulation of oncogenic signaling in EC and provide insights into the possible future directions of targeted therapeutic regimens for EC treatment by developing new agents with fluorescence properties for the clinical applications of integrated diagnosis and treatment.

Gastroprotective effects of polysaccharides from purple sweet potato (Ipomoea batatas (L.) Lam) on an ethanol-induced gastric ulcer via regulating immunity and activating the PI3K/Akt/Rheb/mTOR pathway

The study aimed to investigate the alleviation of an ethanol-induced gastric ulcer in mice by apolysaccharide (PSP) from purple sweet potato (Ipomoea batatas (L.) Lam) and explore the mechanism. The anti-ulcer activity was determined by histopathological evaluation, total gastric acidity, pepsin activity, gastric ulcer index and gastric ulcer inhibition rate. The expression levels of inflammatory factors were detected using ELISA. A special protein meter was used to detect the content of immunoglobulin lgM, immunoglobulin lgG, and complements C3 and C4 in the serum of mice. The expression of CD4+/CD8+ lymphocyte subsets of mice was detected using flow cytometry. Western blot analysis was used to examine the effect of PSP on the PI3K/Akt/Rheb/mTOR pathway. The results showed that PSP could effectively reduce the total gastric acidity, pepsin activity, and the index and inhibition rate of gastric ulcers. At the same time, PSP could significantly increase the levels of immunoglobulins (lgG and lgM) and complements (C3 and C4). It could also increase the activity of peritoneal macrophages in mice and the expression of CD4+/CD8+ in the spleen. ELISA analysis showed that the contents of TNF-α, IL-1β and IL-6 were significantly decreased and the content of IL-10 was significantly increased in the PSP group. The western blot analysis showed that PSP could upregulate the relative protein expressions of MUC5AC, PI3K, p-Akt, Rheb and mTOR. These results indicate that PSP can activate the PI3K/Akt/Rheb/mTOR signaling pathway to improve the immunity of mice and maintain the balance of the immune system, thereby protecting the gastric mucosa and improving stress gastric ulcers.

Preclinical pharmacokinetic characterization of amdizalisib, a novel PI3Kδ inhibitor for the treatment of hematological malignancies

Amdizalisib, also named HMPL-689, a novel selective and potent PI3Kδ inhibitor, is currently under Phase II clinical development in China for treating hematological malignancies. The preclinical pharmacokinetics (PK) of amdizalisib were extensively characterized in vitro and in vivo to support the further development of amdizalisib. We characterized the plasma protein binding, blood-to-plasma partition ratio, cell permeability, hepatic microsomal metabolic stability, and drug-drug interaction potential of amdizalisib using in vitro experiments. In vivo PK assessment was undertaken in mice, rats, dogs, and monkeys following a single intravenous or oral administration of amdizalisib. The tissue distribution and excretion of amdizalisib were evaluated in rats. The PK parameters (CL and Vss) of amdizalisib in preclinical species (mice, rats, dogs, and monkeys) were utilized for the human PK projection using the allometric scaling (AS) approach. Amdizalisib was well absorbed and showed low-to-moderate clearance in mice, rats, dogs, and monkeys. It had high cell permeability without P-glycoprotein (P-gp) or breast cancer resistance protein (BCRP) substrate liability. Plasma protein binding of amdizalisib was high (approximately 90%). It was extensively distributed but with a low brain-to-plasma exposure ratio in rats. Amdizalisib was extensively metabolized in vivo, and the recovery rate of the prototype drug was low in the excreta. Amdizalisib and/or its metabolites were primarily excreted via the bile and urine in rats. Amdizalisib showed inhibition potential on P-gp but not on BCRP and was observed to inhibit CYP2C8 and CYP2C9 with IC50 values of 30.4 and 10.7 μM, respectively. It exhibited induction potential on CYP1A2, CYP2B6, CYP3A4, and CYP2C9. The preclinical data from these ADME studies demonstrate a favorable pharmacokinetic profile for amdizalisib, which is expected to support the future clinical development of amdizalisib as a promising anti-cancer agent.

A review of non-classical MAPK family member, MAPK4: A pivotal player in cancer development and therapeutic intervention

Mitogen-Activated Protein Kinases (MAPKs) are serine/threonine protein kinases that play a crucial role in transmitting extracellular signals to the intracellular environment, influencing a wide range of cellular processes including proliferation, differentiation, apoptosis, metabolic activities, immune function and stress response. MAPK4, a non-classical MAPK, is frequently overexpressed in various malignancies, including prostate, breast, cervix, thyroid, and gliomas. It orchestrates cell proliferation, migration, and apoptosis via the AKT/mTOR and/or PDK1 signaling pathways, thus facilitating tumor cell growth. Furthermore, MAPK4 expression is closely associated with the effectiveness of specific inhibitors like PI3K and PARP1, and also correlate with the survival rates of cancer patients. Increasing evidence highlights MAPK4's involvement in the tumor microenvironment, modulating immune response and inflammation-related diseases. This review comprehensively explores the structure, function, and oncogenic role of MAPK4, providing a deeper understanding of its activation and mechanisms of action in tumorigenesis, which might be helpful for the development of innovative therapeutic strategies for cancer management.

Establishment of canine mammary gland tumor cell lines harboring PI3K/Akt activation as a therapeutic target

Canine mammary gland tumors (MGT) have a poor prognosis in intact female canines, posing a clinical challenge. This study aimed to establish novel canine mammary cancer cell lines from primary tumors and characterize their cellular and molecular features to find potential therapeutic drugs. The MGT cell lines demonstrated rapid cell proliferation and colony formation in an anchorage-independent manner. Vimentin and α-SMA levels were significantly elevated in MGT cell lines compared to normal canine kidney (MDCK) cells, while CDH1 expression was either significantly lower or not detected at all, based on quantitative real-time PCR (qRT-PCR) analysis. Functional annotation and enrichment analysis revealed that epithelial-mesenchymal transition (EMT) phenotypes and tumor-associated pathways, particularly the PI3K/Akt signaling pathway, were upregulated in MGT cells. BYL719 (Alpelisib), a PI3K inhibitor, was also examined for cytotoxicity on the MGT cell lines. The results show that BYL719 can significantly inhibit the proliferation of MGT cell lines in vitro. Overall, our findings suggest that the MGT cell lines may be valuable for future studies on the development, progression, metastasis, and management of tumors.

Elucidating the Role of Lipid-Metabolism-Related Signal Transduction and Inhibitors in Skin Cancer

Lipids, as multifunctional molecules, play a crucial role in a variety of cellular processes. These include regulating membrane glycoprotein functions, controlling membrane trafficking, influencing apoptotic pathways, and affecting drug transport. In addition, lipid metabolites can alter the surrounding microenvironment in ways that might encourage tumor progression. The reprogramming of lipid metabolism is pivotal in promoting tumorigenesis and cancer progression, with tumors often displaying significant changes in lipid profiles. This review concentrates on the essential factors that drive lipid metabolic reprogramming, which contributes to the advancement and drug resistance in melanoma. Moreover, we discuss recent advances and current therapeutic strategies that employ small-molecule inhibitors to target lipid metabolism in skin cancers, particularly those associated with inflammation and melanoma.

Effects of chemical in vitro activation versus fragmentation on human ovarian tissue and follicle growth in culture

STUDY QUESTION

What is the effect of the chemical in vitro activation (cIVA) protocol compared with fragmentation only (Frag, also known as mechanical IVA) on gene expression, follicle activation and growth in human ovarian tissue in vitro?

SUMMARY ANSWER

Although histological assessment shows that cIVA significantly increases follicle survival and growth compared to Frag, both protocols stimulate extensive and nearly identical transcriptomic changes in cultured tissue compared to freshly collected ovarian tissue, including marked changes in energy metabolism and inflammatory responses.

WHAT IS KNOWN ALREADY

Treatments based on cIVA of the phosphatase and tensin homolog (PTEN)-phosphatidylinositol 3-kinase (PI3K) pathway in ovarian tissue followed by auto-transplantation have been administered to patients with refractory premature ovarian insufficiency (POI) and resulted in live births. However, comparable effects with mere tissue fragmentation have been shown, questioning the added value of chemical stimulation that could potentially activate oncogenic responses.

STUDY DESIGN SIZE DURATION

Fifty-nine ovarian cortical biopsies were obtained from consenting women undergoing elective caesarean section (C-section). The samples were fragmented for culture studies. Half of the fragments were exposed to bpV (HOpic)+740Y-P (Frag+cIVA group) during the first 24 h of culture, while the other half were cultured with medium only (Frag group). Subsequently, both groups were cultured with medium only for an additional 6 days. Tissue and media samples were collected for histological, transcriptomic, steroid hormone, and cytokine/chemokine analyses at various time points.

PARTICIPANTS/MATERIALS SETTING METHODS

Effects on follicles were evaluated by counting and scoring serial sections stained with hematoxylin and eosin before and after the 7-day culture. Follicle function was assessed by quantification of steroids by ultra-performance liquid chromatography tandem-mass spectrometry at different time points. Cytokines and chemokines were measured by multiplex assay. Transcriptomic effects were measured by RNA-sequencing (RNA-seq) of the tissue after the initial 24-h culture. Selected differentially expressed genes (DEGs) were validated by quantitative PCR and immunofluorescence in cultured ovarian tissue as well as in KGN cell (human ovarian granulosa-like tumor cell line) culture experiments.

MAIN RESULTS AND THE ROLE OF CHANCE

Compared to the Frag group, the Frag+cIVA group exhibited a significantly higher follicle survival rate, increased numbers of secondary follicles, and larger follicle sizes. Additionally, the tissue in the Frag+cIVA group produced less dehydroepiandrosterone compared to Frag. Cytokine measurement showed a strong inflammatory response at the start of the culture in both groups. The RNA-seq data revealed modest differences between the Frag+cIVA and Frag groups, with only 164 DEGs identified using a relaxed cut-off of false discovery rate (FDR) <0.1. Apart from the expected PI3K-protein kinase B (Akt) pathway, cIVA also regulated pathways related to hypoxia, cytokines, and inflammation. In comparison to freshly collected ovarian tissue, gene expression in general was markedly affected in both the Frag+cIVA and Frag groups, with a total of 3119 and 2900 DEGs identified (FDR < 0.001), respectively. The top enriched gene sets in both groups included several pathways known to modulate follicle growth such as mammalian target of rapamycin (mTOR)C1 signaling. Significant changes compared to fresh tissue were also observed in the expression of genes encoding for steroidogenesis enzymes and classical granulosa cell markers in both groups. Intriguingly, we discovered a profound upregulation of genes related to glycolysis and its upstream regulator in both Frag and Frag+cIVA groups, and these changes were further boosted by the cIVA treatment. Cell culture experiments confirmed glycolysis-related genes as direct targets of the cIVA drugs. In conclusion, cIVA enhances follicle growth, as expected, but the mechanisms may be more complex than PI3K-Akt-mTOR alone, and the impact on function and quality of the follicles after the culture period remains an open question.

LARGE SCALE DATA

Data were deposited in the GEO data base, accession number GSE234765. The code for sequencing analysis can be found in https://github.com/tialiv/IVA_project.

LIMITATIONS REASONS FOR CAUTION

Similar to the published IVA protocols, the first steps in our study were performed in an in vitro culture model where the ovarian tissue was isolated from the regulation of hypothalamic-pituitary-ovarian axis. Further in vivo experiments will be needed, for example in xeno-transplantation models, to explore the long-term impacts of the discovered effects. The tissue collected from patients undergoing C-section may not be comparable to tissue of patients with POI.

WIDER IMPLICATIONS OF THE FINDINGS

The general impact of fragmentation and short (24 h) in vitro culture on gene expression in ovarian tissue far exceeded the effects of cIVA. Yet, follicle growth was stimulated by cIVA, which may suggest effects on specific cell populations that may be diluted in bulk RNA-seq. Nevertheless, we confirmed the impact of cIVA on glycolysis using a cell culture model, suggesting impacts on cellular signaling beyond the PI3K pathway. The profound changes in inflammation and glycolysis following fragmentation and culture could contribute to follicle activation and loss in ovarian tissue culture, as well as in clinical applications, such as fertility preservation by ovarian tissue auto-transplantation.

STUDY FUNDING/COMPETING INTERESTS

This study was funded by research grants from European Union's Horizon 2020 Research and Innovation Programme (Project ERIN No. 952516, FREIA No. 825100), Swedish Research Council VR (2020-02132), StratRegen funding from Karolinska Institutet, KI-China Scholarship Council (CSC) Programme and the Natural Science Foundation of Hunan (2022JJ40782). International Iberian Nanotechnology Laboratory Research was funded by the European Union's H2020 Project Sinfonia (857253) and SbDToolBox (NORTE-01-0145-FEDER-000047), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund. No competing interests are declared.

The PI3K/AKT/mTOR signaling pathway in breast cancer: Review of clinical trials and latest advances

Breast cancer (BC) is the most commonly diagnosed cancer and the leading cause of cancer mortality in women. As the phosphatidylinositol 3-kinase (PI3K) signaling pathway is involved in a wide range of physiological functions of cells including growth, proliferation, motility, and angiogenesis, any alteration in this axis could induce oncogenic features; therefore, numerous preclinical and clinical studies assessed agents able to inhibit the components of this pathway in BC patients. To the best of our knowledge, this is the first study that analyzed all the registered clinical trials investigating safety and efficacy of the PI3K/AKT/mTOR axis inhibitors in BC. Of note, we found that the trends of PI3K inhibitors in recent years were superior as compared with the inhibitors of either AKT or mTOR. However, most of the trials entering phase III and IV used mTOR inhibitors (majorly Everolimus) followed by PI3K inhibitors (majorly Alpelisib) leading to the FDA approval of these drugs in the BC context. Despite favorable efficacies, our analysis shows that the majority of trials are utilizing PI3K pathway inhibitors in combination with hormone therapy and chemotherapy; implying monotherapy cannot yield huge clinical benefits, at least partly, due to the activation of compensatory mechanisms. To emphasize the beneficial effects of these inhibitors in combined-modal strategies, we also reviewed recent studies which investigated the conjugation of nanocarriers with PI3K inhibitors to reduce harmful toxicities, increase the local concentration, and improve their efficacies in the context of BC therapy.

PQR309, a dual PI3K/mTOR inhibitor, synergizes with gemcitabine by impairing the GSK-3β and STAT3/HSP60 signaling pathways to treat nasopharyngeal carcinoma

End-stage nasopharyngeal carcinoma (NPC) has unsatisfactory survival. The limited benefit of chemotherapy and the scarcity of targeted drugs are major challenges in NPC. New approaches to treat late-stage NPC are urgently required. In this study, we explored whether the dual PI3K/mTOR inhibitor, PQR309, exerted a favorable antineoplastic effect and sensitized the response to gemcitabine in NPC. We observed that PI3K expression was positive and elevated in 14 NPC cell lines compared with that in normal nasopharygeal cell lines. Patients with NPC with higher PI3K levels displayed poorer prognosis. We subsequently showed that PQR309 alone effectively decreased the viability, invasiveness, and migratory capability of NPC cells and neoplasm development in mice xenograft models, and dose-dependently induced apoptosis. More importantly, PQR309 remarkably strengthened the anti-NPC function of gemcitabine both in vivo and in vitro. Mechanistically, PQR309 sensitized NPC to gemcitabine by increasing caspase pathway-dependent apoptosis, blocking GSK-3β and STAT3/HSP60 signaling, and ablating epithelial-mesenchyme transition. Thus, targeting PI3K/mTOR using PQR309 might represent a treatment option to promote the response to gemcitabine in NPC, and provides a theoretical foundation for the study of targeted drugs combined with chemotherapy for NPC.

PI3K/Akt/mTOR Signaling Pathway as a Target for Colorectal Cancer Treatment

In the last decade, pathway-specific targeted therapy has revolutionized colorectal cancer (CRC) treatment strategies. This type of therapy targets a tumor-vulnerable spot formed primarily due to an alteration in an oncogene and/or a tumor suppressor gene. However, tumor heterogeneity in CRC frequently results in treatment resistance, underscoring the need to understand the molecular mechanisms involved in CRC for the development of novel targeted therapies. The phosphatidylinositol 3-kinase/protein kinase B/mammalian target of the rapamycin (PI3K/Akt/mTOR) signaling pathway axis is a major pathway altered in CRC. The aberrant activation of this pathway is associated with CRC initiation, progression, and metastasis and is critical for the development of drug resistance in CRC. Several drugs target PI3K/Akt/mTOR in clinical trials, alone or in combination, for the treatment of CRC. This review aims to provide an overview of the role of the PI3K/Akt/mTOR signaling pathway axis in driving CRC, existing PI3K/Akt/mTOR-targeted agents against CRC, their limitations, and future trends.

Targeting autophagy drug discovery: Targets, indications and development trends

Autophagy plays a vital role in sustaining cellular homeostasis and its alterations have been implicated in the etiology of many diseases. Drugs development targeting autophagy began decades ago and hundreds of agents were developed, some of which are licensed for the clinical usage. However, no existing intervention specifically aimed at modulating autophagy is available. The obstacles that prevent drug developments come from the complexity of the actual impact of autophagy regulators in disease scenarios. With the development and application of new technologies, several promising categories of compounds for autophagy-based therapy have emerged in recent years. In this paper, the autophagy-targeted drugs based on their targets at various hierarchical sites of the autophagic signaling network, e.g., the upstream and downstream of the autophagosome and the autophagic components with enzyme activities are reviewed and analyzed respectively, with special attention paid to those at preclinical or clinical trials. The drugs tailored to specific autophagy alone and combination with drugs/adjuvant therapies widely used in clinical for various diseases treatments are also emphasized. The emerging drug design and development targeting selective autophagy receptors (SARs) and their related proteins, which would be expected to arrest or reverse the progression of disease in various cancers, inflammation, neurodegeneration, and metabolic disorders, are critically reviewed. And the challenges and perspective in clinically developing autophagy-targeted drugs and possible combinations with other medicine are considered in the review.

DHCR7 promotes lymph node metastasis in cervical cancer through cholesterol reprogramming-mediated activation of the KANK4/PI3K/AKT axis and VEGF-C secretion

Cervical cancer (CC) patients with lymph node metastasis (LNM) have a poor prognosis. However, the molecular mechanism of LNM in CC is unclear, and there is no effective clinical treatment. Here, we found that 7-dehydrocholesterol reductase (DHCR7), an enzyme that catalyzes the last step of cholesterol synthesis, was upregulated in CC and closely related to LNM. Gain-of-function and loss-of-function experiments proved that DHCR7 promoted the invasion ability of CC cells and lymphangiogenesis in vitro and induced LNM in vivo. The LNM-promoting effect of DHCR7 was partly mediated by upregulating KN motif and ankyrin repeat domains 4 (KANK4) expression and subsequently activating the PI3K/AKT signaling pathway. Alternatively, DHCR7 promoted the secretion of vascular endothelial growth factor-C (VEGF-C), and thereby lymphangiogenesis. Interestingly, cholesterol reprogramming was needed for the DHCR7-mediated promotion of activation of the KANK4/PI3K/AKT axis, VEGF-C secretion, and subsequent LNM. Importantly, treatment with the DHCR7 inhibitors AY9944 and tamoxifen (TAM) significantly inhibited LNM of CC, suggesting the clinical application potential of DHCR7 inhibitors in CC. Collectively, our results uncover a novel molecular mechanism of LNM in CC and identify DHCR7 as a new potential therapeutic target.

Molecular characterization of 13 patients with PIK3CA-related overgrowth spectrum using a targeted deep sequencing approach

Activating variants in the PIK3CA gene cause a heterogeneous spectrum of disorders that involve congenital or early-onset segmental/focal overgrowth, now referred to as PIK3CA-related overgrowth spectrum (PROS). Historically, the clinical diagnoses of patients with PROS included a range of distinct syndromes, including CLOVES syndrome, dysplastic megalencephaly, hemimegalencephaly, focal cortical dysplasia, Klippel-Trenaunay syndrome, CLAPO syndrome, fibroadipose hyperplasia or overgrowth, hemihyperplasia multiple lipomatosis, and megalencephaly capillary malformation-polymicrogyria (MCAP) syndrome. MCAP is a sporadic overgrowth disorder that exhibits core features of progressive megalencephaly, vascular malformations, distal limb malformations, cortical brain malformations, and connective tissue dysplasia. In 2012, our research group contributed to the identification of predominantly mosaic, gain-of-function variants in PIK3CA as an underlying genetic cause of the syndrome. Mosaic variants are technically more difficult to detect and require implementation of more sensitive sequencing technologies and less stringent variant calling algorithms. In this study, we demonstrated the utility of deep sequencing using the Illumina TruSight Oncology 500 (TSO500) sequencing panel in identifying variants with low allele fractions in a series of patients with PROS and suspected mosaicism: pathogenic, mosaic PIK3CA variants were identified in all 13 individuals, including 6 positive controls. This study highlights the importance of screening for low-level mosaic variants in PROS patients. The use of targeted panels with deep sequencing in clinical genetic testing laboratories would improve diagnostic yield and accuracy within this patient population.

Molecular Targeting of the Phosphoinositide-3-Protein Kinase (PI3K) Pathway across Various Cancers

The dysregulation of the phosphatidylinositol-3-kinase (PI3K) pathway can lead to uncontrolled cellular growth and tumorigenesis. Targeting PI3K and its downstream substrates has been shown to be effective in preclinical studies and phase III trials with the approval of several PI3K pathway inhibitors by the Food and Drug Administration (FDA) over the past decade. However, the limited clinical efficacy of these inhibitors, intolerable toxicities, and acquired resistances limit the clinical application of PI3K inhibitors. This review discusses the PI3K signaling pathway, alterations in the PI3K pathway causing carcinogenesis, current and novel PI3K pathway inhibitors, adverse effects, resistance mechanisms, challenging issues, and future directions of PI3K pathway inhibitors.

The Effect and Mechanism of Oleanolic Acid in the Treatment of Metabolic Syndrome and Related Cardiovascular Diseases

Metabolic syndromes (MetS) and related cardiovascular diseases (CVDs) pose a serious threat to human health. MetS are metabolic disorders characterized by obesity, dyslipidemia, and hypertension, which increase the risk of CVDs' initiation and development. Although there are many availabile drugs for treating MetS and related CVDs, some side effects also occur. Considering the low-level side effects, many natural products have been tried to treat MetS and CVDs. A five-cyclic triterpenoid natural product, oleanolic acid (OA), has been reported to have many pharmacologic actions such as anti-hypertension, anti-hyperlipidemia, and liver protection. OA has specific advantages in the treatment of MetS and CVDs. OA achieves therapeutic effects through a variety of pathways, attracting great interest and playing a vital role in the treatment of MetS and CVDs. Consequently, in this article, we aim to review the pharmacological actions and potential mechanisms of OA in treating MetS and related CVDs.

TMEM97 knockdown inhibits 5-fluorouracil resistance by regulating epithelial-mesenchymal transition and ABC transporter expression via inactivating the Akt/mTOR pathway in 5-fluorouracil-resistant colorectal cancer cells

Resistance to 5-fluorouracil (5-FU) is still a primary setback to the success of colorectal cancer (CRC) chemotherapy. Transmembrane protein 97 (TMEM97) functions as an oncogene in CRC. However, the role and mechanism of TMEM97 in regulating 5-FU resistance in CRC cells remains unclear. TMEM97 expression in CRC samples was analyzed by GEPIA and human protein atlas (HPA) databases. TMEM97, E-cadherin, Vimentin, N-cadherin, P-glycoprotein (P-gp), multidrug resistance-associated protein 1 (MRP1)/ABCC1, ABCC2, and the changes of protein kinase B/mammalian target of rapamycin (mTOR) pathway were explored by western blot analysis. IC50 value for 5-FU and cell viability was examined by MTT assay. Apoptosis was evaluated by flow cytometry. TMEM97 was highly expressed in colon adenocarcinoma (COAD) and rectum adenocarcinoma (READ) based on GEPIA and HPA databases. TMEM97 knockdown attenuated 5-FU resistance in HCT116/R and SW480/R cells, as evidenced by the reduced IC50 value for 5-FU and the increased apoptosis. TMEM97 knockdown suppressed epithelial-mesenchymal transition (EMT), expression of ATP-binding cassette (ABC) transporters, and the Akt/mTOR pathway. Mechanistically, activation of Akt/mTOR pathway abolished the inhibitory effects of TMEM97 knockdown on 5-FU resistance, EMT, and ABC transporter expression. In conclusion, TMEM97 knockdown inhibited 5-FU resistance in CRC by regulating EMT and ABC transporter expression via inactivating the Akt/mTOR pathway.

Divergent roles of the regulatory subunits of class IA PI3K

The regulatory subunit of phosphatidylinositol 3-kinase (PI3K), known as p85, is a critical component in the insulin signaling pathway. Extensive research has shed light on the diverse roles played by the two isoforms of p85, namely p85α and p85β. The gene pik3r1 encodes p85α and its variants, p55α and p50α, while pik3r2 encodes p85β. These isoforms exhibit various activities depending on tissue types, nutrient availability, and cellular stoichiometry. Whole-body or liver-specific deletion of pik3r1 have shown to display increased insulin sensitivity and improved glucose homeostasis; however, skeletal muscle-specific deletion of p85α does not exhibit any significant effects on glucose homeostasis. On the other hand, whole-body deletion of pik3r2 shows improved insulin sensitivity with no significant impact on glucose tolerance. Meanwhile, liver-specific double knockout of pik3r1 and pik3r2 leads to reduced insulin sensitivity and glucose tolerance. In the context of obesity, upregulation of hepatic p85α or p85β has been shown to improve glucose homeostasis. However, hepatic overexpression of p85α in the absence of p50α and p55α results in increased insulin resistance in obese mice. p85α and p85β have distinctive roles in cancer development. p85α acts as a tumor suppressor, but p85β promotes tumor progression. In the immune system, p85α facilitates B cell development, while p85β regulates T cell differentiation and maturation. This review provides a comprehensive overview of the distinct functions attributed to p85α and p85β, highlighting their significance in various physiological processes, including insulin signaling, cancer development, and immune system regulation.

The neuroprotection of controlled decompression after traumatic epidural intracranial hypertension through suppression of autophagy via PI3K/Akt signaling pathway

Acute intracranial hypertension (AIH) is a common and tricky symptom that inflicts upon patients after traumatic brain injury (TBI). A variety of clinical options have been applied for the management of AIH, such as physiotherapy, medication, surgery and combination therapy. Specifically, controlled decompression (CDC) alleviates the extent of brain injury and reduces the incidence of a series of post-TBI complications, thereby enhancing the prognosis of patients suffering from acute intracranial hypertension. The objective of the present project is to illuminate the potential molecular mechanism that underlies the neuroprotective effects of CDC in a rat model of traumatic epidural intracranial hypertension (TEIH). Herein, we observed the functional recovery, the degree of brain edema, the level of apoptosis, the expressions of neuronal cell autophagy-related signaling pathway proteins (including Akt, p-Akt, LC3 and Beclin-1) in rat TEIH model at 24 h post-surgery. The results showed in comparison with rapid decompression (RDC), CDC reduced the degree of brain edema, diminished the level of cellular apoptosis and enhanced neurological function, and whereas the neuroprotective effect of CDC could be reversed by rapamycin (Rap). The expressions of Beclin-1 and LC3 in CDC group were significantly lower than those of RDC group, and the expression levels of these two proteins were significantly elevated after the addition of Rap. The expression of p-Akt in CDC group was considerably enhanced than RDC group. After the addition of LY294002, a PI3K/Akt pathway inhibitor, p-Akt protein expression was reduced, and the neuroprotective effect of the rats was markedly inhibited. Taken together, our data demonstrate the superior neuroprotective effect of CDC with regard to alleviating early brain edema, improving the neurological status, suppressing apoptosis and inhibiting neuronal autophagy via triggering PI3K/Akt signaling pathway.

Role of Cannabinoids in Oral Cancer

Cannabinoids have incited scientific interest in different conditions, including malignancy, due to increased exposure to cannabis. Furthermore, cannabinoids are increasingly used to alleviate cancer-related symptoms. This review paper aims to clarify the recent findings on the relationship between cannabinoids and oral cancer, focusing on the molecular mechanisms that could link cannabinoids with oral cancer pathogenesis. In addition, we provide an overview of the current and future perspectives on the management of oral cancer patients using cannabinoid compounds. Epidemiological data on cannabis use and oral cancer development are conflicting. However, in vitro studies assessing the effects of cannabinoids on oral cancer cells have unveiled promising anti-cancer features, including apoptosis and inhibition of cell proliferation. Downregulation of various signaling pathways with anti-cancer effects has been identified in experimental models of oral cancer cells exposed to cannabinoids. Furthermore, in some countries, several synthetic or phytocannabinoids have been approved as medical adjuvants for the management of cancer patients undergoing chemoradiotherapy. Cannabinoids may improve overall well-being by relieving anxiety, depression, pain, and nausea. In conclusion, the link between cannabinoid compounds and oral cancer is complex, and further research is necessary to elucidate the potential risks or their protective impact on oral cancer.

A novel PIK3CA hot-spot mutation in breast cancer patients detected by HRM-COLD-PCR analysis

BACKGROUND

The PI3K protein is involved in the PI3K/AKT/mTOR pathway. Deregulation of this pathway through PIK3CA mutation is common in various tumors. The aim of this work is to identify hotspot mutation at exons 9 and 20 in Tunisian patients with sporadic or hereditary breast cancer.

METHODS

Hotspot mutations in exon 9 and exon 20 of the PIK3CA gene were identified by QPCR-High Resolution Melting followed by COLD-PCR and sequencing in 63 (42 sporadic cases and 21 hereditary cases) tumor tissues collected from Tunisian patient with breast cancer. MCF7, and BT20 breast cancer cell lines harboring the PIK3CA hotspot mutations E545K and H1047R in exon 9 and exon 20 respectively, were used as controls in HRM experiments.

RESULTS

PIK3CA hotspot mutations were detected in 66.7% (28 out of 42) of sporadic BC cases, and in 14.3% (3 out of 21) of hereditary BC. The E545K and the H1048Y were the most prevalent mutations identified in patients with sporadic and hereditary BC, whereas the H1047R hotspot mutation was not found in our patients. Statistical analysis showed that PIK3CA mutation associated with an aggressive behavior in patients with sporadic BC, while it's correlated with age, tumor stage and tumor size in the group patients with hereditary breast cancer.

CONCLUSIONS

Our results showed a novel PIK3CA hotspot mutation in Tunisian breast cancer patients detected by HRM-COLD-PCR. Moreover, the absence of PIK3CA hotspot mutation associated with good prognosis.

Effect and mechanism of Banxia Xiexin decoction in colorectal cancer: A network pharmacology approach

BACKGROUND

Banxia Xiexin decoction (BXD) is a traditional Chinese medicine with anti-colorectal cancer (CRC) activity. However, its bioactive constituents and its mechanism of action remain unclear. Herein, we explored the mechanism of action of BXD against CRC using a network pharmacology approach.

METHODS

First, the targets of the main chemical components of BXD were predicted and collected through a database, and the intersection of compound targets and disease targets was obtained. Subsequently, protein-protein interaction network analysis, Gene Ontology enrichment, and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis were performed to explore the potential mechanisms underlying the effects of BXD on CRC. Finally, a CRC cell model and a CRC xenograft model in nude mice were utilized to further determine the mechanism of action.

RESULTS

A compound-therapeutic target network of BXD was constructed, revealing 146 cellular targets of BXD. The phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling axis was identified as the main target of BXD. Using in vitro and in vivo models, the activity of BXD against CRC was found to be mediated through ferritinophagy by targeting the PI3K/AKT/mTOR axis, leading to intracellular iron accumulation, reactive oxygen species activation, and finally ferroptosis.

CONCLUSIONS

Through the application of network pharmacology and in vitro/in vivo validation experiments, we discovered that BXD exerts anti-CRC effects via the ferritinophagy pathway. Furthermore, we elucidated the potential mechanism underlying its induction of ferritinophagy. These findings demonstrate the significant potential of traditional drugs in managing CRC and support their wider clinical application in combination chemotherapy, targeted therapy, and immunotherapy.

Design, synthesis and evaluation of 2, 6, 8-substituted Imidazopyridine derivatives as potent PI3Kα inhibitors

Inhibition of PI3K pathway has become a desirable strategy for cancer treatment. In this work, a series of 2, 6, 8-substituted Imidazo[1,2-a]pyridine derivatives were designed and screened for their activities against PI3Kα and a panel of PI3Kα-addicted cancer cells. Among them, compound 35 was identified as a PI3Kα inhibitor with nanomolar potency as well as acceptable antiproliferative activity. Flow cytometry analysis confirmed 35 induced cell cycle arrest and apoptosis in T47D cells. In addition, it also showed desirable in vitro ADME properties. The design, synthesis, and SAR exploration of 35 are described within.

Role of m6A modification in regulating the PI3K/AKT signaling pathway in cancer

The phosphoinositide 3-kinase (PI3K)/AKT signaling pathway plays a crucial role in the pathogenesis of cancer. The dysregulation of this pathway has been linked to the development and initiation of various types of cancer. Recently, epigenetic modifications, particularly N6-methyladenosine (m6A), have been recognized as essential contributors to mRNA-related biological processes and translation. The abnormal expression of m6A modification enzymes has been associated with oncogenesis, tumor progression, and drug resistance. Here, we review the role of m6A modification in regulating the PI3K/AKT pathway in cancer and its implications in the development of novel strategies for cancer treatment.

Nrf3 promotes the proliferation and migration of triple‑negative breast cancer by activating PI3K/AKT/mTOR and epithelial‑mesenchymal transition

Nuclear factor erythroid 2-related factor 3 (Nrf3) is increasingly implicated in multiple types of cancer; however, its function in triple-negative breast cancer (TNBC) remains unclear. This study aimed to examine the role of Nrf3 in TNBC. Compared with adjacent normal tissues, TNBC tissues expressed higher levels of Nrf3, and its expression was negatively correlated with survival time. Additionally, Nrf3 knockdown reduced the proliferation and migration of TNBC cells, whereas overexpression of Nrf3 had the opposite effects in vitro and in vivo. Moreover, functional enrichment of TNBC cells overexpressing Nrf3 allowed for the identification of numerous genes and pathways that were altered following Nrf3 overexpression. Further study showed that overexpression of Nrf3 activated the PI3K/AKT/mTOR signaling pathway and regulated the expression of proteins associated with epithelial-mesenchymal transition. Nrf3 was found to directly bind to p110α promoter regions, as evidenced by luciferase reporter and chromatin immunoprecipitation assays. Furthermore, PI3K inhibitors partially decreased the proliferation and migration of the Nrf3 overexpressing TNBC cells. In conclusion, Nrf3 enhances cellular proliferation and migration by activating PI3K/AKT/mTOR signaling pathways, highlighting a novel therapeutic target for TNBC.

Progression of the PI3K/Akt signaling pathway in chronic obstructive pulmonary disease

Chronic Obstructive Pulmonary Disease (COPD) is a chronic respiratory disease characterized by a slow progression and caused by the inhalation of harmful particulate matter. Cigarette smoke and air pollutants are the primary contributing factors. Currently, the pathogenesis of COPD remains incompletely understood. The PI3K/Akt signaling pathway has recently emerged as a critical regulator of inflammation and oxidative stress response in COPD, playing a pivotal role in the disease's progression and treatment. This paper reviews the association between the PI3K/Akt pathway and COPD, examines effective PI3K/Akt inhibitors and novel anti-COPD agents, aiming to identify new therapeutic targets for clinical intervention in this disease.