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

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

LncRNA SLCO4A1-AS1 suppresses lung cancer progression by sequestering the TOX4-NTSR1 signaling axis

BACKGROUND

Metastasis is a multistep process involving the migration and invasion of cancer cells and is a hallmark of cancer malignancy. Long non-coding RNAs (lncRNAs) play critical roles in the regulation of metastasis. This study aims to elucidate the role of the lncRNA solute carrier organic anion transporter family member 4A1-antisense 1 (SLCO4A1-AS1) in metastasis and its underlying regulatory mechanisms.

METHODS

A comprehensive analysis of the Gene Expression Omnibus (GEO) database were used to identify metastasis-associated lncRNAs. Transwell migration and invasion assays, and a tail vein-injection mouse model were used to assess the migration and invasion of cancer cells in vitro and in vivo, respectively. High-throughput screening methods, including MASS Spectrometry and RNA sequencing (RNA-seq), were used to identify the downstream targets of SLCO4A1-AS1. Reverse transcription quantitative polymerase chain reaction (RT-qPCR), western blotting, RNA pull-down, RNA immunoprecipitation (RIP), fluorescence in situ hybridization (FISH), and chromatin immunoprecipitation (ChIp) assays were conducted to identify and validate the underlying regulatory mechanisms of SLCO4A1-AS1.

RESULTS

SLCO4A1-AS1 reduced cancer cell migration and invasion by disrupting cytoskeleton filaments, and was associated with longer overall survival in patients with lung adenocarcinoma. SLCO4A1-AS1 directly interacted with the DNA-binding protein, TOX High Mobility Group Box Family Member 4 (TOX4), to inhibit TOX4-induced migration and invasion. Furthermore, RNA-seq revealed that neurotensin receptor 1 (NTSR1) is a novel and convergent downstream target of SLCO4A1-AS1 and TOX4. Mechanistically, SLCO4A1-AS1 functions as a decoy of TOX4 by interrupting its interaction with the NTSR1 promoter and preventing NTSR1 transcription. Functionally, NTSR1 promotes cancer cell migration and invasion through cytoskeletal remodeling, and knockdown of NTSR1 significantly inhibits TOX4-induced migration and invasion.

CONCLUSION

These findings demonstrated that SLCO4A1-AS1 antagonizes TOX4/NTSR1 signaling, underscoring its pivotal role in lung cancer cell migration and invasion. These findings hold promise for the development of novel therapeutic strategies targeting the SLCO4A1-AS1/TOX4/NTSR1 axis as a potential avenue for effective therapeutic intervention in lung cancer.

AKT-independent signaling in PIK3CA-mutant thyroid cancer mediates resistance to dual SRC and MEK1/2 inhibition

Anaplastic thyroid cancer (ATC) is a rare and aggressive disease with 90% of patients succumbing to this disease 1 year after diagnosis. The approval of the combination therapy of a BRAF inhibitor dabrafenib with the MEK1/2 inhibitor trametinib has improved the overall survival of ATC patients. However, resistance to therapy remains a major problem. We have previously demonstrated combined inhibition of Src with dasatinib and MEK1/2 with trametinib synergistically inhibits growth and induces apoptosis in BRAF- and RAS-mutant thyroid cancer cells, however PIK3CA-mutant cells exhibit a mixed response. Herein, we determined that AKT is not a major mediator of sensitivity and instead PIK3CA-mutants that are resistant to combined dasatinib and trametinib have sustained activation of PDK1 signaling. Furthermore, combined inhibition of PDK1 and MEK1/2 was sufficient to reduce cell viability. These data indicate PDK1 inhibition is a therapeutic option for PIK3CA mutations that do not respond to combined Src and MEK1/2 inhibition.

Agrimoniin is a dual inhibitor of AKT and ERK pathways that inhibit pancreatic cancer cell proliferation

Molecular-targeted therapy has shown its effectiveness in pancreatic cancer, while single-targeted drug often cannot provide long-term benefit because of drug resistance. Fortunately, multitarget combination therapy can reverse drug resistance and achieve better efficacy. The typical treatment characteristics of traditional Chinese medicine monomer on tumor are multiple targets, with small side effects, low toxicity, and so forth. Agrimoniin has been reported to be effective on some cancers, while the mechanism still needs to be clarified. In this study, we used 5-ethynyl-2'-deoxyuridine, cell counting kit-8, flow cytometry, and western blot experiments to confirm that agrimoniin can significantly inhibit the proliferation of pancreatic cancer cell PANC-1 by inducing apoptosis and cell cycle arrest. In addition, by using SC79, LY294002 (the agonist or inhibitor of AKT pathway), and U0126 (the inhibitor of ERK pathway), we found that agrimoniin inhibited cell proliferation by simultaneously inhibiting AKT and ERK pathways. Moreover, agrimoniin could significantly increase the inhibitory effect of LY294002 and U0126 on pancreatic cancer cells. Meanwhile, in vivo experiments also supported the above results. In general, agrimoniin is a double-target inhibitor of AKT and ERK pathways in pancreatic cancer cells; it is expected to be used as a resistance reversal agent of targeted drugs or a synergistic drug of the inhibitor of AKT pathway or ERK pathway.

Discovery of potent and selective PI3Kδ inhibitors bearing amino acid fragments

The selective inhibition of PI3Kδ is a potential therapeutic strategy for the treatment of hematologic malignancies. Herein, we report a series of compounds bearing amino acid fragments as potent and selective PI3Kδ inhibitors. Among them, compound A10 exhibited sub-nanomolar PI3Kδ potency. In cellular assays, A10 achieved strong antiproliferation against SU-DHL-6 cells, and caused cell cycle arrest, and induced apoptosis in SU-DHL-6 cells. The docking study showed that A10 tightly bound to PI3Kδ protein with a planar-shaped conformation. Collectively, compound A10 represented a promising potent and selective PI3Kδ inhibitor bearing amino acid fragement albeit with moderate selectivity over PI3Kγ but superior selectivity against PI3Kα and β. This study suggested that using the amino acid fragments instead of the pyrrolidine ring is new strategy for design of potent PI3Kδ inhibitors.

Aberrant PI3Kδ splice isoform as a potential biomarker and novel therapeutic target for endocrine cancers

Introduction

PI3K/AKT signaling pathway is upregulated in a broad spectrum of cancers. Among the class I PI3Ks (PI3Kδ/β/δ isoforms), PI3Kδ has been implicated in hematologic cancers and solid tumors. Alternative splicing is a post-transcriptional process for acquiring proteomic diversity in eukaryotic cells. Emerging evidence has highlighted the involvement of aberrant mRNA splicing in cancer development/progression.

Methods

Our previous studies revealed that PIK3CD-S is an oncogenic splice variant that promotes tumor aggressiveness and drug resistance in prostate cancer (PCa). To further evaluate the potential of utilizing PI3Kδ-S (encoded from PIK3CD-S) as a cancer biomarker and/or drug target, comprehensive analyses were performed in a series of patient samples and cell lines derived from endocrine/solid tumors. Specifically, IHC, immunofluorescence, western blot and RT-PCR assay results have demonstrated that PI3Kδ isoforms were highly expressed in endocrine/solid tumor patient specimens and cell lines.

Results

Differential PIK3CD-S/PIK3CD-L expression profiles were identified in a panel of endocrine/solid tumor cells. SiRNA knockdown of PIK3CD-L or PIK3CD-S differentially inhibits AKT/mTOR signaling in PCa, breast, colon and lung cancer cell lines. Moreover, siRNA knockdown of PTEN increased PI3Kδ levels and activated AKT/mTOR signaling, while overexpression of PTEN reduced PI3Kδ levels and inhibited AKT/mTOR signaling in cancer cells. Intriguingly, PI3Kδ-S levels remained unchanged upon either siRNA knockdown or overexpression of PTEN. Taken together, these results suggested that PTEN negatively regulates PI3Kδ-L and its downstream AKT/mTOR signaling, while PI3Kδ-S promotes AKT/mTOR signaling without regulation by PTEN. Lastly, PI3Kδ inhibitor Idelalisib and SRPK1/2 inhibitor SRPIN340 were employed to assess their efficacies on inhibiting the PI3Kδ-expressing endocrine/solid tumors. Our results have shown that Idelalisib effectively inhibited PI3Kδ-L (but not PI3Kδ-S) mediated AKT/mTOR signaling. In contrast, SRPIN340 reversed the aberrant mRNA splicing, thereby inhibiting AKT/mTOR signaling. In-vitro functional assays have further demonstrated that a combination of Idelalisib and SRPIN340 achieved a synergistic drug effect (with drastically reduced cell viabilities/growths of tumor spheroids) in inhibiting the advanced tumor cells.

Conclusion

In summary, our study has suggested a promising potential of utilizing PI3Kδ-S (an oncogenic isoform conferring drug resistance and exempt from PTEN regulation) as a prognostic biomarker and drug target in advanced endocrine cancers.

Discovery of a Novel Photocaged PI3K Inhibitor Capable of Real-Time Reporting of Drug Release

A novel photocaged PI3K inhibitor 2 was designed and synthesized by introducing a cascade photocaging group to block its key interaction with the kinase. Upon UV light irradiation, the photocaged compound released a highly potent PI3K inhibitor to recover its anticancer properties and a fluorescent dye for real-time reporting of drug release, providing a new approach for studying the PI3K signaling transduction pathway as well as developing precisely controlled cancer therapeutics.

Cardiometabolic health, menopausal estrogen therapy and the brain: How effects of estrogens diverge in healthy and unhealthy preclinical models of aging

Research in preclinical models indicates that estrogens are neuroprotective and positively impact cognitive aging. However, clinical data are equivocal as to the benefits of menopausal estrogen therapy to the brain and cognition. Pre-existing cardiometabolic disease may modulate mechanisms by which estrogens act, potentially reducing or reversing protections they provide against cognitive decline. In the current review we propose mechanisms by which cardiometabolic disease may alter estrogen effects, including both alterations in actions directly on brain memory systems and actions on cardiometabolic systems, which in turn impact brain memory systems. Consideration of mechanisms by which estrogen administration can exert differential effects dependent upon health phenotype is consistent with the move towards precision or personalized medicine, which aims to determine which treatment interventions will work for which individuals. Understanding effects of estrogens in both healthy and unhealthy models of aging is critical to optimizing the translational link between preclinical and clinical research.

The role of immune checkpoint inhibition in triple negative breast cancer

INTRODUCTION

Immunotherapy has revolutionized cancer treatment, including TNBC, which has limited options of treatment and poor prognosis. ICIs studied in TNBC include pembrolizumab, nivolumab, atezolizumab, and durvalumab. Initial studies exploring ICI monotherapy demonstrated promising yet limited responses. Subsequent studies, KEYNOTE 522 and KEYNOTE 355, which combined ICI with chemotherapy, have resulted in the FDA approval of pembrolizumab in the early-stage and metastatic setting, respectively.

AREAS COVERED

This article provides a comprehensive review of the role of ICI in the treatment of TNBC. We reviewed the trials that have evaluated ICI monotherapy, dual therapy, ICI in combination with chemotherapy, targeted therapy, vaccines and radiation. Additionally, we reviewed potential biomarkers of response and immune-related adverse events (irAEs). A literature search was conducted via PubMed and ClinicalTrials.gov as of 5 June 2023.

EXPERT OPINION

Various approaches combining immunotherapy with chemotherapy, targeted therapy, vaccines and radiation have been assessed. Pembrolizumab remains the only ICI approved in both the early stage and mTNBC. The role of adjuvant pembrolizumab in those who achieved pCR after neoadjuvant therapy is being investigated. Combining ICI with PARP inhibitors and radiation shows promise. More research is needed in identifying predictors of response. Monitoring of irAEs remains crucial.

Hesperidin, a Bioflavonoid in Cancer Therapy: A Review for a Mechanism of Action through the Modulation of Cell Signaling Pathways

Cancer represents one of the most frequent causes of death in the world. The current therapeutic options, including radiation therapy and chemotherapy, have various adverse effects on patients' health. In this vista, the bioactive ingredient of natural products plays a vital role in disease management via the inhibition and activation of biological processes such as oxidative stress, inflammation, and cell signaling molecules. Although natural products are not a substitute for medicine, they can be effective adjuvants or a type of supporting therapy. Hesperidin, a flavonoid commonly found in citrus fruits, with its potential antioxidant, anti-inflammatory, and hepatoprotective properties, and cardio-preventive factor for disease prevention, is well-known. Furthermore, its anticancer potential has been suggested to be a promising alternative in cancer treatment or management through the modulation of signal transduction pathways, which includes apoptosis, cell cycle, angiogenesis, ERK/MAPK, signal transducer, and the activator of transcription and other cell signaling molecules. Moreover, its role in the synergistic effects with anticancer drugs and other natural compounds has been described properly. The present article describes how hesperidin affects various cancers by modulating the various cell signaling pathways.

EGFL6 promotes bone metastasis of lung adenocarcinoma by increasing cancer cell malignancy and bone resorption

Lung adenocarcinoma is the most common and aggressive type of lung cancer with the highest incidence of bone metastasis. Epidermal growth factor-like domain multiple 6 (EGFL6) is an exocrine protein, and the expression of EGFL6 is correlated with survival of patient with lung adenocarcinoma. However, the association between EGFL6 expression in lung adenocarcinoma and bone metastasis has not been investigated. In this study, we found that EGFL6 levels in lung adenocarcinoma tissues correlate with bone metastasis and TNM stages in surgical patients. In vitro, overexpression of EGFL6 in lung adenocarcinoma cells promoted their proliferation, migration, and invasion ability compared with control by enhancing EMT process and activating Wnt/β-catenin and PI3K/AKT/mTOR pathways. In the nude mouse model, overexpression of EGFL6 enhanced tumor growth and caused greater bone destruction. Moreover, the exocrine EGFL6 of human lung adenocarcinoma cells increased osteoclast differentiation of bone marrow mononuclear macrophages (BMMs) of mice via the NF-κB and c-Fos/NFATc1 signaling pathways. However, exocrine EGFL6 had no effect on osteoblast differentiation of bone marrow mesenchymal stem cells (BMSCs). In conclusion, high expression of EGFL6 in lung adenocarcinomas is associated with bone metastasis in surgical patients. The underlying mechanism may be the increased metastatic properties of lung adenocarcinoma cells with high EGFL6 level and the enhanced osteoclast differentiation and bone resorption by exocrine EGFL6 from tumors. Therefore, EGFL6 is a potential therapeutic target to reduce the ability of lung adenocarcinomas to grow and metastasize and to preserve bone mass in patients with bone metastases from lung adenocarcinomas.

The PI3K-Akt-mTOR and Associated Signaling Pathways as Molecular Drivers of Immune-Mediated Inflammatory Skin Diseases: Update on Therapeutic Strategy Using Natural and Synthetic Compounds

The dysregulated phosphatidylinositol-3-kinase (PI3K)-Akt-mammalian target of rapamycin (mTOR) signaling pathway has been implicated in various immune-mediated inflammatory and hyperproliferative dermatoses such as acne, atopic dermatitis, alopecia, psoriasis, wounds, and vitiligo, and is associated with poor treatment outcomes. Improved comprehension of the consequences of the dysregulated PI3K/Akt/mTOR pathway in patients with inflammatory dermatoses has resulted in the development of novel therapeutic approaches. Nonetheless, more studies are necessary to validate the regulatory role of this pathway and to create more effective preventive and treatment methods for a wide range of inflammatory skin diseases. Several studies have revealed that certain natural products and synthetic compounds can obstruct the expression/activity of PI3K/Akt/mTOR, underscoring their potential in managing common and persistent skin inflammatory disorders. This review summarizes recent advances in understanding the role of the activated PI3K/Akt/mTOR pathway and associated components in immune-mediated inflammatory dermatoses and discusses the potential of bioactive natural products, synthetic scaffolds, and biologic agents in their prevention and treatment. However, further research is necessary to validate the regulatory role of this pathway and develop more effective therapies for inflammatory skin disorders.

Comprehensive insight into altered host cell-signaling cascades upon Helicobacter pylori and Epstein-Barr virus infections in cancer

Cancer is characterized by mutagenic events that lead to disrupted cell signaling and cellular functions. It is one of the leading causes of death worldwide. Literature suggests that pathogens, mainly Helicobacter pylori and Epstein-Barr virus (EBV), have been associated with the etiology of human cancer. Notably, their co-infection may lead to gastric cancer. Pathogen-mediated DNA damage could be the first and crucial step in the carcinogenesis process that modulates numerous cellular signaling pathways. Altogether, it dysregulates the metabolic pathways linked with cell growth, apoptosis, and DNA repair. Modulation in these pathways leads to abnormal growth and proliferation. Several signaling pathways such RTK, RAS/MAPK, PI3K/Akt, NFκB, JAK/STAT, HIF1α, and Wnt/β-catenin are known to be altered in cancer. Therefore, this review focuses on the oncogenic roles of H. pylori, EBV, and its associated signaling cascades in various cancers. Scrutinizing these signaling pathways is crucial and may provide new insights and targets for preventing and treating H. pylori and EBV-associated cancers.

Multi-Targeted and On-Demand Non-Coding RNA Regulation Nanoplatform against Metastasis and Recurrence of Triple-Negative Breast Cancer

Dysregulation of microRNAs (miRs) is the hallmark of triple-negative breast cancer (TNBC), which is closely involved with its growth, metastasis, and recurrence. Dysregulated miRs are promising targets for TNBC therapy, however, targeted and accurate regulation of multiple disordered miRs in tumors is still a great challenge. Here, a multi-targeting and on-demand non-coding RNA regulation nanoplatform (MTOR) is reported to precisely regulate disordered miRs, leading to dramatical suppression of TNBC growth, metastasis, and recurrence. With the assistance of long blood circulation, ligands of urokinase-type plasminogen activator peptide and hyaluronan located in multi-functional shells enable MTOR to actively target TNBC cells and breast cancer stem cell-like cells (BrCSCs). After entering TNBC cells and BrCSCs, MTOR is subjected to lysosomal hyaluronidase-induced shell detachment, leading to an explosion of the TAT-enriched core, thereby enhancing nuclear targeting. Subsequently, MTOR could precisely and simultaneously downregulate microRNA-21 expression and upregulate microRNA-205 expression in TNBC. In subcutaneous xenograft, orthotopic xenograft, pulmonary metastasis, and recurrence TNBC mouse models, MTOR shows remarkably synergetic effects on the inhibition of tumor growth, metastasis, and recurrence due to its on-demand regulation of disordered miRs. This MTOR system opens a new avenue for on-demand regulation of disordered miRs against growth, metastasis, and recurrence of TNBC.

Istradefylline induces A2A/P2X7 crosstalk expression inducing pro-inflammatory signal, and reduces AKT/mTOR signaling in melanoma-bearing mice

ATP and adenosine (ADO) are critical players in the context of cancer. In the tumor microenvironment, the signaling dependent on these molecules, and immune cells, is regulated by an enzymatic chain and purinergic receptors called purinome. Primarily, the A2A receptor (A2AR) has a pro-tumor action since it reduces the immune response and favors the growth of malignant melanoma. Therefore, this study aimed to verify the effects of A2AR antagonism with Istradefylline (IST) on the purinergic signaling profile of the melanoma tumor and immunological compartments. We observed reduced tumor growth of melanoma in IST-treated animals. IST inhibited AKT/mTOR pathway, which is involved with tumor growth. In the tumor, spleen, and thymus, the modulation of purinergic enzymes (CD39, CD73, and E-ADA) characterized a pro-inflammatory profile since it favored increased extracellular concentrations of ATP to the detriment of ADO. A2AR inhibition generated a compensatory feedback process with increased A2AR expression at the tumor level. However, there was also an increase in the expression of the P2X7 receptor (P2X7R), which culminated in an increase in pro-inflammatory pathways with the release of IL-1β and pro-inflammatory cytokines such as IFN-γ and TNF-α. Our data evidence the cross-involvement between expression and action of the A2AR and P2X7R. We suggest that IST is a promising drug for off-label use in cancer since it promotes an anti-tumoral response by producing pro-inflammatory cytokines and blocking of AKT/mTOR tumor growth pathway.

Effects and Mechanisms of Kaempferol in the Management of Cancers through Modulation of Inflammation and Signal Transduction Pathways

Cancer is the principal cause of death and its incidence is increasing continuously worldwide. Various treatment approaches are in practice to treat cancer, but these treatment strategies may be associated with severe side effects and also produce drug resistance. However, natural compounds have established their role in cancer management with minimal side effects. In this vista, kaempferol, a natural polyphenol, mainly found in vegetables and fruits, has been revealed to have many health-promoting effects. Besides its health-promoting potential, its anti-cancer potential has also been described in in vivo as well as in in vitro studies. The anti-cancer potential of kaempferol has been proven through modulation of cell signaling pathways in addition to the induction of apoptosis and cell cycle arrest in cancer cells. It leads to the activation of tumor suppressor genes, inhibition of angiogenesis, PI3K/AKT pathways, STAT3, transcription factor AP-1, Nrf2 and other cell signaling molecules. Poor bioavailability of this compound is one of the major limitations for its proper and effective disease management actions. Recently, some novel nanoparticle-based formulations have been used to overcome these limitations. The aim of this review is to provide a clear picture regarding the mechanism of action of kaempferol in different cancers through the modulation of cell signaling molecules. Besides this, strategies to improve the efficacy and synergistic effects of this compound have also been described. However, more studies are needed based on clinical trials to fully explore the therapeutic role of this compound, especially in cancer treatment.

PI3K/AKT/mTOR Dysregulation and Reprogramming Metabolic Pathways in Renal Cancer: Crosstalk with the VHL/HIF Axis

Renal cell carcinoma (RCC) represents 85-95% of kidney cancers and is the most frequent type of renal cancer in adult patients. It accounts for 3% of all cancer cases and is in 7th place among the most frequent histological types of cancer. Clear cell renal cell carcinoma (ccRCC), accounts for 75% of RCCs and has the most kidney cancer-related deaths. One-third of the patients with ccRCC develop metastases. Renal cancer presents cellular alterations in sugars, lipids, amino acids, and nucleic acid metabolism. RCC is characterized by several metabolic dysregulations including oxygen sensing (VHL/HIF pathway), glucose transporters (GLUT 1 and GLUT 4) energy sensing, and energy nutrient sensing cascade. Metabolic reprogramming represents an important characteristic of the cancer cells to survive in nutrient and oxygen-deprived environments, to proliferate and metastasize in different body sites. The phosphoinositide 3-kinase-AKT-mammalian target of the rapamycin (PI3K/AKT/mTOR) signaling pathway is usually dysregulated in various cancer types including renal cancer. This molecular pathway is frequently correlated with tumor growth and survival. The main aim of this review is to present renal cancer types, dysregulation of PI3K/AKT/mTOR signaling pathway members, crosstalk with VHL/HIF axis, and carbohydrates, lipids, and amino acid alterations.

Detailed curriculum vitae of HER2-targeted therapy

With the booming development of precision medicine, molecular targeted therapy has been widely used in clinical oncology treatment due to a smaller number of side effects and its superior accuracy compared to that of traditional strategies. Among them, human epidermal growth factor receptor 2 (HER2)-targeted therapy has attracted considerable attention and has been used in the clinical treatment of breast and gastric cancer. Despite excellent clinical effects, HER2-targeted therapy remains in its infancy due to its resulting inherent and acquired resistance. Here, a comprehensive overview of HER2 in numerous cancers is presented, including its biological role, involved signaling pathways, and the status of HER2-targeted therapy.

Scandium-44: Diagnostic Feasibility in Tumor-Related Angiogenesis

Angiogenesis-related cell-surface molecules, including integrins, aminopeptidase N, vascular endothelial growth factor, and gastrin-releasing peptide receptor (GRPR), play a crucial role in tumour formation. Radiolabelled imaging probes targeting angiogenic biomarkers serve as valuable vectors in tumour identification. Nowadays, there is a growing interest in novel radionuclides other than gallium-68 (⁶⁸Ga) or copper-64 (⁶⁴Cu) to establish selective radiotracers for the imaging of tumour-associated neo-angiogenesis. Given its ideal decay characteristics (E_β⁺_average: 632 KeV) and a half-life (T_1/2 = 3.97 h) that is well matched to the pharmacokinetic profile of small molecules targeting angiogenesis, scandium-44 (⁴⁴Sc) has gained meaningful attention as a promising radiometal for positron emission tomography (PET) imaging. More recently, intensive research has been centered around the investigation of ⁴⁴Sc-labelled angiogenesis-directed radiopharmaceuticals. Previous studies dealt with the evaluation of ⁴⁴Sc-appended a_vb₃ integrin-affine Arg-Gly-Asp (RGD) tripeptides, GRPR-selective aminobenzoyl-bombesin analogue (AMBA), and hypoxia-associated nitroimidazole derivatives in the identification of various cancers using experimental tumour models. Given the tumour-related hypoxia- and angiogenesis-targeting capability of these PET probes, ⁴⁴Sc seems to be a strong competitor of the currently used positron emitters in radiotracer development. In this review, we summarize the preliminary preclinical achievements with ⁴⁴Sc-labelled angiogenesis-specific molecular probes.

Comparative transcriptome analysis of endothelial progenitor cells of HbSS patients with and without proliferative retinopathy

Among sickle cell anemia (SCA) complications, proliferative sickle cell retinopathy (PSCR) is one of the most important, being responsible for visual impairment in 10-20% of affected eyes. The aim of this study was to identify differentially expressed genes (DEGs) present in pathways that may be implicated in the pathophysiology of PSCR from the transcriptome profile analysis of endothelial progenitor cells. RNA-Seq was used to compare gene expression profile of circulating endothelial colony-forming cells (ECFCs) from HbSS patients with and without PSCR. Furthermore, functional enrichment analysis and protein-protein interaction (PPI) networks were performed to gain further insights into biological functions. The differential expression analysis identified 501 DEGs, when comparing the groups with and without PSCR. Furthermore, functional enrichment analysis showed associations of the DEGs in 200 biological processes. Among these, regulation of mitogen-activated protein (MAP) kinase activity, positive regulation of phosphatidylinositol 3-kinase (PI3K), and positive regulation of Signal Transducer and Activator of Transcription (STAT) receptor signaling pathway were observed. These pathways are associated with angiogenesis, cell migration, adhesion, differentiation, and proliferation, important processes involved in PSCR pathophysiology. Moreover, our results showed an over-expression of VEGFC (vascular endothelial growth factor-C) and FLT1 (Fms-Related Receptor Tyrosine Kinase 1) genes, when comparing HbSS patients with and without PSCR. These results may indicate a possible association between VEGFC and FLT1 receptor, which may activate signaling pathways such as PI3K/AKT and MAPK/ERK and contribute to the mechanisms implicated in neovascularization. Thus, our findings contain preliminary results that may guide future studies in the field, since the molecular mechanisms of PSCR are still poorly understood.

Pharmacological PI3K inhibition in head and neck squamous cell carcinoma: A systematic review

BACKGROUND

This systematic review aimed to investigate the in vitro and in vivo effects of phosphatidylinositol-3-kinase (PI3K) inhibitors on head and neck squamous cell carcinoma (HNSCC). Considering the role of PI3K and its downstream effectors in cell proliferation, invasion, and survival, it is reasonable to expect that treatment with PI3K inhibitors could control HNSCC onset and progression. Thus, the research question for our review was whether pharmacological inhibition of PI3K affects HNSCC progression.

METHODS

In vitro and in vivo studies were selected from six databases. We collected data regarding cell viability, apoptosis, and the regulation of protein expression levels from in vitro studies. For the in vivo studies, we analyzed the reduction in tumor size or gene and protein expression.

RESULTS

The included studies showed reduced cell proliferation and apoptosis after treatment with PI3K inhibitors. PI3K inhibitors in combination with other drugs had an enhanced anticancer effects compared to those of single-drug treatments.

CONCLUSIONS

The results support the potential of PI3K inhibitors as candidates for clinical trials in HNSCC.

Phytoestrogens, novel dietary supplements for breast cancer

While endocrine therapy is considered as an effective way to treat breast cancer, it still faces many challenges, such as drug resistance and individual discrepancy. Therefore, novel preventive and therapeutic modalities are still in great demand to decrease the incidence and mortality rate of breast cancer. Numerous studies suggested that G protein-coupled estrogen receptor (GPER), a membrane estrogen receptor, is a potential target for breast cancer prevention and treatment. It was also shown that not only endogenous estrogens can activate GPERs, but many phytoestrogens can also function as selective estrogen receptor modulators (SERMs) to interact GPERs. In this review, we discussed the possible mechanisms of GPERs pathways and shed a light of developing novel phytoestrogens based dietary supplements against breast cancers.

Metabolic Interventions in Tumor Immunity: Focus on Dual Pathway Inhibitors

The metabolism of tumors and immune cells in the tumor microenvironment (TME) can affect the fate of cancer and immune responses. Metabolic reprogramming can occur following the activation of metabolic-related signaling pathways, such as phosphoinositide 3-kinases (PI3Ks) and the mammalian target of rapamycin (mTOR). Moreover, various tumor-derived immunosuppressive metabolites following metabolic reprogramming also affect antitumor immune responses. Evidence shows that intervention in the metabolic pathways of tumors or immune cells can be an attractive and novel treatment option for cancer. For instance, administrating inhibitors of various signaling pathways, such as phosphoinositide 3-kinases (PI3Ks), can improve T cell-mediated antitumor immune responses. However, dual pathway inhibitors can significantly suppress tumor growth more than they inhibit each pathway separately. This review discusses the latest metabolic interventions by dual pathway inhibitors as well as the advantages and disadvantages of this therapeutic approach.

Antitumor activity of the PI3K δ-sparing inhibitor MEN1611 in PIK3CA mutated, trastuzumab-resistant HER2 + breast cancer

PURPOSE

Dysregulation of the PI3K pathway is one of the most common events in breast cancer. Here we investigate the activity of the PI3K inhibitor MEN1611 at both molecular and phenotypic levels by dissecting and comparing its profile and efficacy in HER2 + breast cancer models with other PI3K inhibitors.

METHODS

Models with different genetic backgrounds were used to investigate the pharmacological profile of MEN1611 against other PI3K inhibitors. In vitro studies evaluated cell viability, PI3K signaling, and cell death upon treatment with MEN1611. In vivo efficacy of the compound was investigated in cell line- and patient-derived xenografts models.

RESULTS

Consistent with its biochemical selectivity, MEN1611 demonstrated lower cytotoxic activity in a p110δ-driven cellular model when compared to taselisib, and higher cytotoxic activity in the p110β-driven cellular model when compared to alpelisib. Moreover, MEN1611 selectively decreased the p110α protein levels in PIK3CA mutated breast cancer cells in a concentration- and proteasome-dependent manner. In vivo, MEN1611 monotherapy showed significant and durable antitumor activity in several trastuzumab-resistant PIK3CA-mutant HER2 + PDX models. The combination of trastuzumab and MEN1611 significantly improved the efficacy compared to single agent treatment.

CONCLUSIONS

The profile of MEN1611 and its antitumoral activity suggest an improved profile as compared to pan-inhibitors, which are limited by a less than ideal safety profile, and isoform selective molecules, which may potentially promote development of resistance mechanisms. The compelling antitumor activity in combination with trastuzumab in HER2 + trastuzumab-resistant, PIK3CA mutated breast cancer models is at the basis of the ongoing B-Precise clinical trial (NCT03767335).

Transcriptome Analysis on Hepatopancreas Reveals the Metabolic Dysregulation Caused by Vibrio parahaemolyticus Infection in Litopenaeus vannamei

Acute hepatopancreas necrosis disease (AHPND) has caused massive deaths of shrimp and has led to huge economic losses in aquaculture. Vibrio parahaemolyticus (VPAHPND) carrying a plasmid encoding binary toxins homologous to the photorhabdus insect-related (Pir) toxins is one of the main pathogens causing this disease. Previous studies have reported many immune-related genes of shrimp in response to this pathogenic bacteria. However, few studies have so far focused on the metabolic changes in Litopenaeus vannamei upon VPAHPND infection. In the present study, comparative transcriptomic analysis was performed on the hepatopancreas of shrimp at different times during VPAHPND infection. Functional analyses on the differentially expressed genes (DEGs) during infection showed that pathways related to glucose, energy and amino acid metabolism, as well as nucleic acid synthesis, were obviously changed in the hepatopancreas after VPAHPND infection. Additionally, three signaling pathways, which could regulate metabolic processes, including HIF-1 signaling pathway, PI3K-Akt signaling pathway and NF-KappaB signaling pathway, also changed significantly. Collectively, these data reveal a close relationship between host metabolism processes and Vibrio infection. The information will enrich our understanding of the interaction mechanism between the shrimp and Vibrio.

Cellular Labeling of Phosphatidylserine Using Clickable Serine Probes

Phosphatidylserine (PS) is a key lipid that plays important roles in disease-related biological processes, and therefore, the means to track PS in live cells are invaluable. Herein, we describe the metabolic labeling of PS in Saccharomyces cerevisiae cells using analogues of serine, a PS precursor, derivatized with azide moieties at either the amino (N-l-SerN3) or carbonyl (C-l-SerN3) groups. The conservative click tag modification enabled these compounds to infiltrate normal lipid biosynthetic pathways, thereby producing tagged PS molecules as supported by mass spectrometry studies, thin-layer chromatography (TLC) analysis, and further derivatization with fluorescent reporters via click chemistry to enable imaging in yeast cells. This approach shows strong prospects for elucidating the complex biosynthetic and trafficking pathways involving PS.

Drugging Hijacked Kinase Pathways in Pediatric Oncology: Opportunities and Current Scenario

Childhood cancer is considered rare, corresponding to ~3% of all malignant neoplasms in the human population. The World Health Organization (WHO) reports a universal occurrence of more than 15 cases per 100,000 inhabitants around the globe, and despite improvements in diagnosis, treatment and supportive care, one child dies of cancer every 3 min. Consequently, more efficient, selective and affordable therapeutics are still needed in order to improve outcomes and avoid long-term sequelae. Alterations in kinases' functionality is a trademark of cancer and the concept of exploiting them as drug targets has burgeoned in academia and in the pharmaceutical industry of the 21st century. Consequently, an increasing plethora of inhibitors has emerged. In the present study, the expression patterns of a selected group of kinases (including tyrosine receptors, members of the PI3K/AKT/mTOR and MAPK pathways, coordinators of cell cycle progression, and chromosome segregation) and their correlation with clinical outcomes in pediatric solid tumors were accessed through the R2: Genomics Analysis and Visualization Platform and by a thorough search of published literature. To further illustrate the importance of kinase dysregulation in the pathophysiology of pediatric cancer, we analyzed the vulnerability of different cancer cell lines against their inhibition through the Cancer Dependency Map portal, and performed a search for kinase-targeted compounds with approval and clinical applicability through the CanSAR knowledgebase. Finally, we provide a detailed literature review of a considerable set of small molecules that mitigate kinase activity under experimental testing and clinical trials for the treatment of pediatric tumors, while discuss critical challenges that must be overcome before translation into clinical options, including the absence of compounds designed specifically for childhood tumors which often show differential mutational burdens, intrinsic and acquired resistance, lack of selectivity and adverse effects on a growing organism.