Class I phosphatidylinositol 3-kinase inhibitors for cancer therapy

TIPRL, a Potential Double-edge Molecule to be Targeted and Re-targeted Toward Cancer

The target of rapamycin (TOR) proteins exhibits phylogenetic conservation across various species, ranging from yeast to humans, and are classified as members of the phosphatidylinositol kinase (PIK)-related kinase family. Multiple serine/threonine (Ser/Thr) protein phosphatases (PP)2A, PP4, and PP6, have been recognized as constituents of the TOR signaling pathway in mammalian cells. The protein known as TOR signaling pathway regulator-like (TIPRL) functions as a regulatory agent by impeding the activity of the catalytic subunits of PP2A. Various cellular contexts have been postulated for TIPRL, encompassing the regulation of mechanistic target of rapamycin (mTOR) signaling, inhibition of apoptosis and biogenesis, and recycling of PP2A. According to reports, there has been an observed increase in TIPRL levels in several types of carcinomas, such as non-small-cell lung carcinoma (NSCLC) and hepatocellular carcinomas (HCC). This review aims to comprehensively examine the significance of the Tor pathway in regulating apoptosis and proliferation of cancer cells, with a specific focus on the role of TOR signaling and TIPRL in cancer.

The Role of the PI3K/Akt/mTOR Axis in Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) is one of the most common malignancies globally, representing a significant public health problem with a poor prognosis. The development of efficient therapeutic strategies for HNSCC prevention and treatment is urgently needed. The PI3K/AKT/mTOR (PAM) signaling pathway is a highly conserved transduction network in eukaryotic cells that promotes cell survival, growth, and cycle progression. Dysfunction in components of this pathway, such as hyperactivity of PI3K, loss of PTEN function, and gain-of-function mutations in AKT, are well-known drivers of treatment resistance and disease progression in cancer. In this review, we discuss the major mutations and dysregulations in the PAM signaling pathway in HNSCC. We highlight the results of clinical trials involving inhibitors targeting the PAM signaling pathway as a strategy for treating HNSCC. Additionally, we examine the primary mechanisms of resistance to drugs targeting the PAM pathway and potential therapeutic strategies.

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

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

Signaling pathways in liver cancer: pathogenesis and targeted therapy

Liver cancer remains one of the most prevalent malignancies worldwide with high incidence and mortality rates. Due to its subtle onset, liver cancer is commonly diagnosed at a late stage when surgical interventions are no longer feasible. This situation highlights the critical role of systemic treatments, including targeted therapies, in bettering patient outcomes. Despite numerous studies on the mechanisms underlying liver cancer, tyrosine kinase inhibitors (TKIs) are the only widely used clinical inhibitors, represented by sorafenib, whose clinical application is greatly limited by the phenomenon of drug resistance. Here we show an in-depth discussion of the signaling pathways frequently implicated in liver cancer pathogenesis and the inhibitors targeting these pathways under investigation or already in use in the management of advanced liver cancer. We elucidate the oncogenic roles of these pathways in liver cancer especially hepatocellular carcinoma (HCC), as well as the current state of research on inhibitors respectively. Given that TKIs represent the sole class of targeted therapeutics for liver cancer employed in clinical practice, we have particularly focused on TKIs and the mechanisms of the commonly encountered phenomena of its resistance during HCC treatment. This necessitates the imperative development of innovative targeted strategies and the urgency of overcoming the existing limitations. This review endeavors to shed light on the utilization of targeted therapy in advanced liver cancer, with a vision to improve the unsatisfactory prognostic outlook for those patients.

Exploring the Mechanisms of Traditional Chinese Herbal Therapy in Gastric Cancer: A Comprehensive Network Pharmacology Study of the Tiao-Yuan-Tong-Wei decoction

The use of herbal medicine as an adjuvant therapy in the management of gastric cancer has yielded encouraging outcomes, notably in enhancing overall survival rates and extending periods of disease remission. Additionally, herbal medicines have demonstrated potential anti-metastatic effects in gastric cancer. Despite these promising findings, there remains a significant gap in our understanding regarding the precise pharmacological mechanisms, the identification of specific herbal compounds, and their safety and efficacy profiles in the context of gastric cancer therapy. In addressing this knowledge deficit, the present study proposes a comprehensive exploratory analysis of the Tiao-Yuan-Tong-Wei decoction (TYTW), utilizing an integrative approach combining system pharmacology and molecular docking techniques. This investigation aims to elucidate the pharmacological actions of TYTW in gastric pathologies. It is hypothesized that the therapeutic efficacy of TYTW in counteracting gastric diseases stems from its ability to modulate key signaling pathways, thereby influencing PIK3CA activity and exerting anti-inflammatory effects. This modulation is observed predominantly in pathways such as PI3K/AKT, MAPK, and those directly associated with gastric cancer. Furthermore, the study explores how TYTW's metabolites (agrimoniin, baicalin, corosolic acid, and luteolin) interact with molecular targets like AKT1, CASP3, ESR1, IL6, PIK3CA, and PTGS2, and their subsequent impact on these critical pathways and biological processes. Therefore, this study represents preliminary research on the anticancer molecular mechanism of TYTW by performing network pharmacology and providing theoretical evidence for further experimental investigations.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Design, synthesis, molecular docking, and in vitro studies of 2-mercaptoquinazolin-4(3H)-ones as potential anti-breast cancer agents

Triple-negative breast cancer (TNBC) comprises 10 % to 20 % of breast cancer, however, it is more dangerous than other types of breast cancer, because it lacks druggable targets, such as the estrogen receptors (ER) and the progesterone receptor (PR), and has under expressed receptor tyrosine kinase, ErbB2. Present targeted therapies are not very effective and other choices include invasive procedures like surgery or less invasive ones like radiotherapy and chemotherapy. This study investigated the potential anticancer activity of some novel quinazolinone derivatives that were designed on the structural framework of two approved anticancer drugs, Ispinesib (KSP inhibitor) and Idelalisib (PI3Kδ inhibitor), to find out solutions for TNBC. All the designed derivatives (3a-l) were subjected to extra precision molecular docking and were synthesized and spectrally characterized. In vitro enzyme inhibition assay of compounds (3a, 3b, 3e, 3 g and 3 h) revealed their nanomolar inhibitory potential against the anticancer targets, KSP and PI3Kδ. Using MTT assay, the cytotoxic potential of compounds 3a, 3b and 3e were found highest against MDA-MB-231 cells with an IC50 of 14.51 µM, 16.27 µM, and 9.97 µM, respectively. Remarkably, these compounds were recorded safe against the oral epithelial normal cells with an IC50 values of 293.60 µM, 261.43 µM, and 222 µM, respectively. The anticancer potential of these compounds against MDA-MB-231 cells was revealed to be associated with their apoptotic activity. This was established by examination with the inverted microscope that revealed the appearance of various apoptotic features like cell shrinkage, apoptotic bodies, and membrane blebbing. Using flow cytometry, the Annexin V/PI-stained cancer cells showed an increase in early and late apoptotic cells. In addition, DNA fragmentation was revealed to occur after treatment with the tested compounds by gel electrophoresis. The relative gene expression of pro-apoptotic and anti-apoptotic genes revealed an overexpression of the P53 and BAX genes and a downregulation of the BCL-2 gene by real-time PCR. So, this work proved that compounds 3a, 3b, and 3e could be developed as anticancer candidates, via their P53-dependent apoptotic activity.

Recent Advances in Structural Optimization of Quinazoline-Based Protein Kinase Inhibitors for Cancer Therapy (2021-Present)

Cancer is a complicated, multifaceted disease that can impact any organ in the body. Various chemotherapeutic agents have a low selectivity and are very toxic when used alone or in combination with others. Resistance is one of the most important hurdles that develop due to the use of many anticancer therapeutics. As a result, treating cancer requires a target-specific palliative care strategy. Remarkable scientific discoveries have shed light on several of the molecular mechanisms underlying cancer, resulting in the development of various targeted anticancer agents. One of the most important heterocyclic motifs is quinazoline, which has a wide range of biological uses and chemical reactivities. Newer, more sophisticated medications with quinazoline structures have been found in the last few years, and great strides have been made in creating effective protocols for building these pharmacologically active scaffolds. A new class of chemotherapeutic agents known as quinazoline-based derivatives possessing anticancer properties consists of several well-known compounds that block different protein kinases and other molecular targets. This review highlights recent updates (2021-2024) on various quinazoline-based derivatives acting against different protein kinases as anticancer chemotherapeutics. It also provides guidance for the design and synthesis of novel quinazoline analogues that could serve as lead compounds.

Hepatocellular carcinoma: signaling pathways, targeted therapy, and immunotherapy

Hepatocellular carcinoma (HCC) is the most common primary liver cancer with a high mortality rate. It is regarded as a significant public health issue because of its complicated pathophysiology, high metastasis, and recurrence rates. There are no obvious symptoms in the early stage of HCC, which often leads to delays in diagnosis. Traditional treatment methods such as surgical resection, radiotherapy, chemotherapy, and interventional therapies have limited therapeutic effects for HCC patients with recurrence or metastasis. With the development of molecular biology and immunology, molecular signaling pathways and immune checkpoint were identified as the main mechanism of HCC progression. Targeting these molecules has become a new direction for the treatment of HCC. At present, the combination of targeted drugs and immune checkpoint inhibitors is the first choice for advanced HCC patients. In this review, we mainly focus on the cutting-edge research of signaling pathways and corresponding targeted therapy and immunotherapy in HCC. It is of great significance to comprehensively understand the pathogenesis of HCC, search for potential therapeutic targets, and optimize the treatment strategies of HCC.

Exploring the dual role of circRNA and PI3K/AKT pathway in tumors of the digestive system

The interactions among circRNAs, the PI3K/AKT pathway, and their downstream effectors are intricately linked to their functional roles in tumorigenesis. Furthermore, the circRNAs/PI3K/AKT axis has been significantly implicated in the context of digestive system tumors. This axis is frequently abnormally activated in digestive cancers, including gastric cancer, colorectal cancer, pancreatic cancer, and others. Moreover, the overactivation of the circRNAs/PI3K/AKT axis promotes tumor cell proliferation, suppresses apoptosis, enhances invasive and metastatic capabilities, and contributes to drug resistance. In this regard, gaining crucial insights into the complex interaction between circRNAs and the PI3K/AKT pathway holds great potential for elucidating disease mechanisms, identifying diagnostic biomarkers, and designing targeted therapeutic interventions.

Systematical Evaluation of the Structure-Cardiotoxicity Relationship of 7-Azaindazole-based PI3K Inhibitors Designed by Bioisosteric Approach

A growing concern of cardiotoxicity induced by PI3K inhibitors has raised the requirements to evaluate the structure-cardiotoxicity relationship (SCR) in the development process of novel inhibitors. Based on three bioisosteric 7-azaindazole-based candidate inhibitors namely FD269, FD268 and FD274 that give same order of inhibitory concentration 50% (IC50) magnitude against PI3Ks, in this work, we proposed to systematically evaluate the SCR of 7-azaindazole-based PI3K inhibitors designed by bioisosteric approach. The 24-h lethal concentrations 50% (LC50) of FD269, FD268 and FD274 against zebrafish embryos were 0.35, 4.82 and above 50 μM (not detected), respectively. Determination of the heart rate, pericardial and yolk-sac areas and vascular malformation confirmed the remarkable reduction in the cardiotoxicity of from FD269 to FD268 and to FD274. The IC50s of all three compounds against the hERG channel were tested on the CHO cell line that constitutively expressing hERG channel, which were all higher than 20 μM. The transcriptomic analysis revealed that FD269 and FD268 induced the up-regulation of noxo1b, which encodes a subunit of an NADPH oxidase evoking the oxidative stress. Furthermore, immunohistochemistry tests confirmed the structure-dependent attenuation of the overproduction of ROS and cardiac apoptosis. Our results verified the feasibility of bioisosteric replacement to attenuate the cardiotoxicity of 7-azaindazole-based PI3K inhibitors, suggesting that the screening for PI3K inhibitors with both high potency and low cardiotoxicity from bioisosteres would be a beneficial trial.

A review: FDA-approved fluorine-containing small molecules from 2015 to 2022

Fluorine-containing small molecules have occupied a special position in drug discovery research. The successful clinical use of fluorinated corticosteroids in the 1950s and fluoroquinolones in the 1980s led to an ever-increasing number of approved fluorinated compounds over the last 50 years. They have shown various biological properties such as antitumor, antimicrobial, and anti-inflammatory activities. Fluoro-pharmaceuticals have been considered a strong and practical tool in the rational drug design approach due to their benefits from potency and ADME (absorption, distribution, metabolism, and excretion) points of view. Herein, approved fluorinated drugs from 2015 to 2022 were reviewed.

Design, synthesis and bioactivity evaluation of selenium-containing PI3Kδ inhibitors

PI3Kδ inhibitors play an important role in the treatment of leukemia, lymphoma and autoimmune diseases. Herein, using our reported compounds as the lead compound, we designed and synthesized a series of selenium-containing PI3Kδ inhibitors based on quinazoline and pyrido[3,2-d]pyrimidine skeletons. Among them, compound Se15 showed sub-nanomolar inhibition against PI3Kδ and strong δ-selectivity. Moreover, Se15 showed potent anti-proliferative effect on SU-DHL-6 cells with an IC50 value of 0.16 μM. Molecular docking study showed that Se15 was able to form multiple hydrogen bonds with PI3Kδ and was close proximity and stacking with PI3Kδ selective region. In conclusion, the Se-containing compound Se15 bearing pyrido[3,2-d]pyrimidine scaffold is a novel potent and selective PI3Kδ inhibitor. The introduction of selenium can enrich the structure of PI3Kδ inhibitors and provide a new idea for design of novel PI3Kδ inhibitors.

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.

Roles of phosphatidylinositol-3-kinases signaling pathway in inflammation-related cancer: Impact of rs10889677 variant and buparlisib in colitis-associated cancer

BACKGROUND

Phosphatidylinositol-3-kinases (PI3K) is a well-known route in inflammation-related cancer. Recent discovery on PI3K-related genes revealed a potential variant that links ulcerative colitis (UC) and colorectal cancer (CRC) with colitis-associated cancer (CAC). PI3K/AKT pathway has been recommended as a potential additional therapeutic option for CRC due to its substantial role in modifying cellular processes. Buparlisib is a pan-class I PI3K inhibitor previously shown to reduce tumor growth.

AIM

To investigate the regulation of rs10889677 and the role of buparlisib in the PI3K signaling pathway in CAC pathogenesis.

METHODS

Genomic DNA from 32 colonic samples, including CAC (n = 7), UC (n = 10) and CRC (n = 15), was sequenced for the rs10889677 mutation. The mutant and wildtype fragments were amplified and cloned in the pmirGLO vector. The luciferase activity of cloned vectors was assessed after transfection into the HT29 cell line. CAC mice were induced by a mixture of a single azoxymethane injection and three cycles of dextran sulphate sodium, then buparlisib was administered after 14 d. The excised colon was subjected to immunohistochemistry for Ki67 and Cleaved-caspase-3 markers and quantitative real-time polymerase chain reaction analysis for Pdk1 and Sgk2.

RESULTS

Luciferase activity decreased by 2.07-fold in the rs10889677 mutant, confirming the hypothesis that the variant disrupted miRNA binding sites, which led to an increase in IL23R expression and the activation of the PI3K signaling pathway. Furthermore, CAC-induced mice had a significantly higher disease activity index (P < 0.05). Buparlisib treatment significantly decreased mean weight loss in CAC-induced mice (P < 0.05), reduced the percentage of proliferating cells by 5%, and increased the number of apoptotic cells. The treatment also caused a downward trend of Pdk1 expression and significantly decreased Sgk2 expression.

CONCLUSION

Our findings suggested that the rs10889677 variant as a critical initiator of the PI3K signaling pathway, and buparlisib had the ability to prevent PI3K-non-AKT activation in the pathophysiology of CAC.

Mechanism of anticancer effect of ETP-45658, a PI3K/AKT/mTOR pathway inhibitor on HT-29 Cells

The PI3K pathway plays a crucial role in tumor cell proliferation across various cancers, including colon cancer, making it a promising treatment target. This study aims to investigate the antiproliferative activity of ETP-45658, a PI3K/AKT/mTOR pathway inhibitor, on colon cancer and elucidate the underlying mechanisms. HT-29 colon cancer cells were treated with varying doses of ETP 45658 and its cytotoxic effect assessed using the XTT cell viability assay.ELISA was also used to measure TAS, TOS, Bax, BCL-2, cleaved caspase 3, cleaved PARP, and 8-oxo-dG levels. Flow cytometry was performed to investigate apoptosis, cell cycle, caspase 3/7 activity, and mitochondrial membrane potential. Additionally, following the administration of DAPI (4,6-diamidino-2-phenylindole) dye, the cells were visualized using an immunofluorescence microscope. It was observed that ETP-45658 exerted a dose-dependent and statistically significant antiproliferative effect on HT-29 colon cancer cells. Further investigations using the IC50 dose showed that ETP-45658 decreased TAS levels and increased TOS levels and revealed that it upregulated apoptotic proteins while downregulating anti-apoptotic proteins. Our findings also showed that it increased Annexin V binding, arrested the cell cycle at G0/G1 phase, induced caspase 3/7 activity, impaired mitochondrial membrane potential, and ultimately triggered apoptosis in HT-29 cells. ETP-45658 shows promise against colon cancer by inducing cell death, and oxidative stress, and arresting the cell cycle. Targeting the PI3K/AKT/mTOR pathway with ETP-45658 offers exciting potential for colon cancer treatment.

Development of PI3Kα inhibitors for tumor therapy

The PI3K/AKT/mTOR signaling pathway is well known to be involved in cell growth, proliferation, metabolism and other cellular physiological processes. Abnormal activation of this pathway is closely related to tumorigenesis and metastasis. As the starting node of the pathway, PI3K is known to contain 4 isoforms, including PI3Kα, a heterodimer composed of the catalytic subunit p110α and the regulatory subunit p85. PIK3CA, which encodes p110α, is frequently mutated in cancer, especially breast cancer. Abnormal activation of PI3Kα promotes cancer cell proliferation, migration, invasion, and angiogenesis; therefore, PI3Kα has become a key target for the development of anticancer drugs. The hinge region and the region of the mutation site in the PI3Kα protein are important for designing PI3Kα-specific inhibitors. As the group shared by the most PI3Kα-specific inhibitors reported thus far, carboxamide can produce hydrogen bonds with Gln859 and Ser854. Gln859 is specific to the p110α protein in producing hydrogen bond interactions with PI3Kα-specific inhibitors and this is a key point for designing PI3Kα inhibitors. To date, alpelisib is the only PI3Kα inhibitor approved for the treatment of breast cancer. Several other PI3Kα inhibitors are under evaluation in clinical trials. In this review, we briefly describe PI3Kα and its role in tumorigenesis, summarize the clinical trial results of some PI3Kα inhibitors as well as the synthetic routes of alpelisib, and finally give our proposal for the development of novel PI3Kα inhibitors for tumor therapy. HighlightsWe summarize the progress of PI3Kα and PI3Kα inhibitors in cancer from the second half of the 20th century to the present.We describe the clinical trial results of PI3Kα inhibitors as well as the synthetic routes of the only approved PI3Kα inhibitor alpelisib.Crystal structure of alpelisib bound to the PI3Kα receptor binding domain.This review gives proposal for the development of novel PI3Kα inhibitors and will serve as a complementary summary to other reviews in the research field of PI3K inhibitors.Communicated by Ramaswamy H. Sarma.

Machine Learning Reveals Lipidome Remodeling Dynamics in a Mouse Model of Ovarian Cancer

Ovarian cancer (OC) is one of the deadliest cancers affecting the female reproductive system. It may present little or no symptoms at the early stages and typically unspecific symptoms at later stages. High-grade serous ovarian cancer (HGSC) is the subtype responsible for most ovarian cancer deaths. However, very little is known about the metabolic course of this disease, particularly in its early stages. In this longitudinal study, we examined the temporal course of serum lipidome changes using a robust HGSC mouse model and machine learning data analysis. Early progression of HGSC was marked by increased levels of phosphatidylcholines and phosphatidylethanolamines. In contrast, later stages featured more diverse lipid alterations, including fatty acids and their derivatives, triglycerides, ceramides, hexosylceramides, sphingomyelins, lysophosphatidylcholines, and phosphatidylinositols. These alterations underscored unique perturbations in cell membrane stability, proliferation, and survival during cancer development and progression, offering potential targets for early detection and prognosis of human ovarian cancer.

Machine Learning Reveals Lipidome Remodeling Dynamics in a Mouse Model of Ovarian Cancer

Ovarian cancer (OC) is one of the deadliest cancers affecting the female reproductive system. It may present little or no symptoms at the early stages, and typically unspecific symptoms at later stages. High-grade serous ovarian cancer (HGSC) is the subtype responsible for most ovarian cancer deaths. However, very little is known about the metabolic course of this disease, particularly in its early stages. In this longitudinal study, we examined the temporal course of serum lipidome changes using a robust HGSC mouse model and machine learning data analysis. Early progression of HGSC was marked by increased levels of phosphatidylcholines and phosphatidylethanolamines. In contrast, later stages featured more diverse lipids alterations, including fatty acids and their derivatives, triglycerides, ceramides, hexosylceramides, sphingomyelins, lysophosphatidylcholines, and phosphatidylinositols. These alterations underscored unique perturbations in cell membrane stability, proliferation, and survival during cancer development and progression, offering potential targets for early detection and prognosis of human ovarian cancer.

Teaser

Time-resolved lipidome remodeling in an ovarian cancer model is studied through lipidomics and machine learning.

Nanomaterial-mediated low-temperature photothermal therapy via heat shock protein inhibition

With the continuous development of nanobiotechnology in recent years, combining photothermal materials with nanotechnology for tumor photothermal therapy (PTT) has drawn many attentions nanomedicine research. Although nanomaterial-mediated PTT is more specific and targeted than traditional treatment modalities, hyperthermia can also damage normal cells. Therefore, researchers have proposed the concept of low-temperature PTT, in which the expression of heat shock proteins (HSPs) is inhibited. In this article, the research strategies proposed in recent years based on the inhibition of HSPs expression to achieve low-temperature PTT was reviewed. Folowing this, the synthesis, properties, and applications of these nanomaterials were introduced. In addition, we also summarized the problems of nanomaterial-mediated low-temperature PTT at this stage and provided an outlook on future research directions.

Developing therapeutic approaches for chronic myeloid leukemia: a review

Modern clinical therapy of chronic myeloid leukemia (CML) with TKIs is highly efficacious in most CML patients, while it is not remedial and generally confined due to intolerance or resistance. CML is currently considered a severe disease. Interestingly, stem cell transplantation in the past decade was an attractive clinical therapeutic option in CML patients, but it is not successful due to independently more death rates in older patients. So, the targeting of BCR::ABL oncoprotein is extensively used to enhance the reduction in a higher percentage of CML patients by tyrosine kinase inhibitors (TKIs). However, resistance or intolerance responses to these inhibitors are responsible for future deterioration and further development of disease. At this point, the clinical treatment of CML is a major challenge, and the lack of molecular responses to TKIs are not succeeded with chemotherapy alone. So, the considerable efficacious clinical necessities remain unmet. Therefore, continuous efforts are needed to explore new potential treatment strategies with an increasing understanding of CML biology. Therefore, this review deals with the investigation of TKI treatment with interferon, chemotherapy (Hydroxyurea, Homoharringtonine, Omacetaxine, Cytarabine), and several other new TKIs under beneficial clinical trials. Additionally, the approaches towards TKIs-resistant or intolerant CML cells where the respective signaling pathway gets up-regulated are also targeted with its inhibitor. This review presents evidence that new TKIs under clinical and pre-clinical trials may improve the chemotherapy of CML.

Discovery of Novel PI3Kδ Inhibitors Based on the p110δ Crystal Structure

PI3Kδ is a key mediator of B-cell receptor signaling and plays an important role in the pathogenesis of certain hematological malignancies, such as chronic lymphocytic leukemia. Idelalisib, which targets PI3Kδ specifically, is the first approved PI3K inhibitor for cancer therapy. Recently, we carried out virtual screening, cell-based assays, adapta kinase assays, and molecular dynamic analysis to discover novel PI3Kδ inhibitors and identified NSC348884 as a lead PI3Kδ inhibitor. NSC348884 had an excellent docking score, potent PI3Kδ-inhibitory activity, antitumor effects on various cancer cell lines, and a favorable binding mode with the active site of PI3Kδ. Moreover, through the structural modification of NSC348884, we further discovered comp#1, which forms H-bonds with both Val828 and Lys779 in the ATP binding pocket of PI3Kδ, with a more favorable conformation binding to PI3Kδ. In addition, we found that N¹, N¹, N²-trimethyl-N²-((6-methyl-1H-benzo[d]imidazol-2-yl) methyl) ethane-1,2-diamine might be a potential scaffold structure. Thus, the result of this study provides a far more efficient approach for discovering novel inhibitors targeting PI3Kδ.

Design, synthesis, and biological evaluation of novel dual inhibitors of heat shock protein 90/mammalian target of rapamycin (Hsp90/mTOR) against bladder cancer cells

In this study, a novel class of thieno [2,3-d] pyrimidine derivatives containing resorcinol and morpholine fragments as Hsp90/mTOR dual inhibitors was designed, synthesized, and evaluated. In vitro anti-tumor assay results: the obtained compounds demonstrated effectiveness in suppressing the enzymatic activities of the Hsp90 and mTOR and inhibiting the proliferation of J82, T24, and SW780 cancer cell lines. Among these dual inhibitors, the most potent compound 17o, confirmed remarkable inhibitory activities on Hsp90, mTOR, and SW780 cell. Furthermore, the molecular dynamics simulation and a panel of mechanism studies revealed that inhibitor 17o suppressed the proliferation of SW780 cells through the over-activation of the PI3K/AKT/mTOR pathway regulated by mTOR inhibition and apoptosis regulated by the mitochondrial pathway. In subcutaneous J82 xenograft models, the compound 17o also presented considerable in vivo anti-tumor activity. Therefore, our investigations highlight that a new-found dual Hsp90/mTOR inhibitor by rational drug design strategies could be a promising lead compound for targeted bladder cancer therapy and deserves further studies.

Genes of the Ubiquitin Proteasome System Qualify as Differential Markers in Malignant Glioma of Astrocytic and Oligodendroglial Origin

We have mined public genomic datasets to identify genes coding for components of the ubiquitin proteasome system (UPS) that may qualify as potential diagnostic and therapeutic targets in the three major glioma types, astrocytoma (AS), glioblastoma (GBM), and oligodendroglioma (ODG). In the Sun dataset of glioma (GEO ID: GSE4290), expression of the genes UBE2S and UBE2C, which encode ubiquitin conjugases important for cell-cycle progression, distinguished GBM from AS and ODG. KEGG analysis showed that among the ubiquitin E3 ligase genes differentially expressed, the Notch pathway was significantly over-represented, whereas among the E3 ligase adaptor genes the Hippo pathway was over-represented. We provide evidence that the UPS gene contributions to the Notch and Hippo pathway signatures are related to stem cell pathways and can distinguish GBM from AS and ODG. In the Sun dataset, AURKA and TPX2, two cell-cycle genes coding for E3 ligases, and the cell-cycle gene coding for the E3 adaptor CDC20 were upregulated in GBM. E3 ligase adaptor genes differentially expressed were also over-represented for the Hippo pathway and were able to distinguish classic, mesenchymal, and proneural subtypes of GBM. Also over-expressed in GBM were PSMB8 and PSMB9, genes encoding subunits of the immunoproteasome. Our transcriptome analysis provides a strong rationale for UPS members as attractive therapeutic targets for the development of more effective treatment strategies in malignant glioma. Ubiquitin proteasome system and glioblastoma: E1-ubiquitin-activating enzyme, E2-ubiquitin-conjugating enzyme, E3-ubiquitin ligase. Ubiquitinated substrates of E3 ligases may be degraded by the proteasome. Expression of genes for specific E2 conjugases, E3 ligases, and genes for proteasome subunits may serve as differential markers of subtypes of glioblastoma.

ZSTK474 Sensitizes Glioblastoma to Temozolomide by Blocking Homologous Recombination Repair

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults. Temozolomide (TMZ) is used as the standard chemotherapeutic agent for GBM but with limited success, and treatment failure is mainly due to tumor resistance. One of the leading causes of TMZ resistance is the upregulation of the DNA repair mechanism. Therefore, targeting the DNA damage response (DDR) is proposed to be an effective strategy to sensitize tumor cells to TMZ. In the present study, we demonstrated that the combined use of the PI3K inhibitor ZSTK474 and TMZ showed synergetic anticancer effects on human GBM cells in vitro and in vivo. The combination treatment led to significantly increased cell apoptosis and DNA double strand breaks (DSBs). In addition, a mechanistic study indicated that TMZ enhanced the homologous recombination (HR) repair efficiency in GBM cells, while ZSTK474 impaired HR repair by blocking the phosphorylation of ATM and the expression of BRCA1/2 and Rad51, thereby sensitizing GBM cells to TMZ. Moreover, TMZ activated the PI3K signaling pathway through upregulation of the PI3K catalytic subunits p110α and p110β and the phosphorylation of Akt. Meanwhile, ZSTK474 blocked the activity of the PI3K/Akt pathway. Taken together, our findings suggested that the combination of ZSTK474 and TMZ might be a potential therapeutic option for GBM.

Discovery, Optimization, and Evaluation of Potent and Selective PI3Kδ-γ Dual Inhibitors for the Treatment of B-cell Malignancies

Nowadays, PI3Kδ-γ dual inhibitors have been approved for the treatment of B-cell malignancies. Dual inhibition of PI3Kδ and PI3Kγ represents a unique therapeutic opportunity and may confer greater benefits than either isoform inhibition alone in the management of hematological malignancies. However, currently available dual inhibitors of PI3Kδ-γ compromise in at least one of several essential properties in terms of potency, selectivity, and pharmacokinetic (PK) profiles. Hence, the main challenge of our optimization campaign was to identify an oral available PI3Kδ-γ dual inhibitor with an optimum balance of potency, selectivity, and PK profiles. The medicinal chemistry efforts culminated in the discovery of compound 58, which exhibited strong potency and high selectivity along with excellent in vivo profiles as demonstrated through PK studies in rats and through pharmacodynamic studies in an SUDHL-6 xenograft model. All the results suggest that compound 58 may be a promising candidate for the treatment of B-cell malignancies.

Reducing PDK1/Akt Activity: An Effective Therapeutic Target in the Treatment of Alzheimer's Disease

Alzheimer’s disease (AD) is a common age-related neurodegenerative disease that leads to memory loss and cognitive function damage due to intracerebral neurofibrillary tangles (NFTs) and amyloid-β (Aβ) protein deposition. The phosphoinositide-dependent protein kinase (PDK1)/protein kinase B (Akt) signaling pathway plays a significant role in neuronal differentiation, synaptic plasticity, neuronal survival, and neurotransmission via the axon–dendrite axis. The phosphorylation of PDK1 and Akt rises in the brain, resulting in phosphorylation of the TNF-α-converting enzyme (TACE) at its cytoplasmic tail (the C-terminal end), changing its internalization as well as its trafficking. The current review aimed to explain the mechanisms of the PDK1/Akt/TACE signaling axis that exerts its modulatory effect on AD physiopathology. We provide an overview of the neuropathological features, genetics, Aβ aggregation, Tau protein hyperphosphorylation, neuroinflammation, and aging in the AD brain. Additionally, we summarized the phosphoinositide 3-kinase (PI3K)/PDK1/Akt pathway-related features and its molecular mechanism that is dependent on TACE in the pathogenesis of AD. This study reviewed the relationship between the PDK1/Akt signaling pathway and AD, and discussed the role of PDK1/Akt in resisting neuronal toxicity by suppressing TACE expression in the cell membrane. This work also provides a perspective for developing new therapeutics targeting PDK1/Akt and TACE for the treatment of AD.

How Phosphofructokinase-1 Promotes PI3K and YAP/TAZ in Cancer: Therapeutic Perspectives

Simple Summary

We propose that PFK1 promotes a positive feedback loop with PI3K/AKT and YAP/TAZ signaling pathways in cancer cells. Therefore, targeting PFK1 (or its product F-1,6-BP) could improve the efficacy of PI3K and YAP/TAZ inhibitors currently tested in clinical trials. To this aim, we suggest the use of citrate, which is a physiologic and potent inhibitor of PFK1.

Abstract

PI3K/AKT is one of the most frequently altered signaling pathways in human cancers, supporting the activation of many proteins sustaining cell metabolism, proliferation, and aggressiveness. Another important pathway frequently altered in cancer cells is the one regulating the YAP/TAZ transcriptional coactivators, which promote the expression of genes sustaining aerobic glycolysis (such as WNT, MYC, HIF-1), EMT, and drug resistance. Of note, the PI3K/AKT pathway can also regulate the YAP/TAZ one. Unfortunately, although PI3K and YAP inhibitors are currently tested in highly resistant cancers (both solid and hematologic ones), several resistance mechanisms may arise. Resistance mechanisms to PI3K inhibitors may involve the stimulation of alternative pathways (such as RAS, HER, IGFR/AKT), the inactivation of PTEN (the physiologic inhibitor of PI3K), and the expression of anti-apoptotic Bcl-xL and MCL1 proteins. Therefore, it is important to improve current therapeutic strategies to overcome these limitations. Here, we want to highlight how the glycolytic enzyme PFK1 (and its product F-1,6-BP) promotes the activation of both PI3K/AKT and YAP/TAZ pathways by several direct and indirect mechanisms. In turn, PI3K/AKT and YAP/TAZ can promote PFK1 activity and F-1,6-BP production in a positive feedback loop, thus sustaining the Warburg effect and drug resistance. Thus, we propose that the inhibition of PFK1 (and of its key activator PFK2/PFKFB3) could potentiate the sensitivity to PI3K and YAP inhibitors currently tested. Awaiting the development of non-toxic inhibitors of these enzymes, we propose to test the administration of citrate at a high dosage, because citrate is a physiologic inhibitor of both PFK1 and PFK2/PFKFB3. Consistently, in various cultured cancer cells (including melanoma, sarcoma, hematologic, and epithelial cancer cells), this “citrate strategy” efficiently inhibits the IGFR1/AKT pathway, promotes PTEN activity, reduces Bcl-xL and MCL1 expression, and increases sensitivity to standard chemotherapy. It also inhibits the development of sarcoma, pancreatic, mammary HER⁺ and lung RAS-driven tumors in mice without apparent toxicities.

Crosstalk between PI3K/AKT/mTOR and WNT/β-Catenin signaling in GBM - Could combination therapy checkmate the collusion?

Glioblastoma multiforme is one of the calamitous primary glial brain tumors with extensive heterogeneity at cellular and molecular levels. While maximal surgical resection trailed by radio and chemotherapy employing temozolomide remains the gold-standard treatment for malignant glioma patients, the overall prognosis remains dismal and there exists an unmet need for effective therapeutic strategies. In this context, we hypothesize that proper understanding of signaling pathways responsible for glioblastoma multiforme proliferation would be the first trump card while searching for novel targeted therapies. Among the pathways aberrantly activated, PI3K/AKT/mTOR is the most significant pathway, that is clinically implicated in malignancies such as high-grade glioma. Further, the WNT/β-Catenin cascade is well-implicated in several malignancies, while its role in regulating glioma pathogenesis has only emerged recently. Nevertheless, oncogenic activation of both these pathways is a frequent event in malignant glioma that facilitates tumor proliferation, stemness and chemo-resistance. Recently, it has been reported that the cross-talk of PI3K/AKT/mTOR pathway with multiple signaling pathways could promote glioma progression and reduce the sensitivity of glioma cells to the standard therapy. However, very few studies had focused on the relationship between PI3K/AKT/mTOR and WNT/β-Catenin pathways in glioblastoma multiforme. Interestingly, in homeostatic and pathologic circumstances, both these pathways depict fine modulation and are connected at multiple levels by upstream and downstream effectors. Thus, gaining deep insights on the collusion between these pathways would help in discovering unique therapeutic targets for glioblastoma multiforme management. Hence, the current review aims to address, "the importance of inter-play between PI3K/AKT/mTOR and WNT/β-Catenin pathways", and put forward, "the possibility of combinatorially targeting them", for glioblastoma multiforme treatment enhancement.

Molecular characterization of NCLIV_011700 of Neospora caninum, a low sequence identity rhoptry protein

Neospora caninum is an obligate intracellular parasite related to abortion in cattle, goats and sheep. The life cycle of N. caninum is characterized by the time-coordinated secretion of proteins contained in micronemes, rhoptries and dense granules, allowing the active invasion and the adaptation of the parasite in the cell environment. Thus, the proteins of the secretome have the potential to be considered as targets for N. caninum control. Despite the importance of neosporosis in the livestock-related economy, no commercial treatment is available. Furthermore, the process of invasion, propagation and immune evasion are not completely elucidated. In this study, we initiated the characterization of NCLIV_011700 of N. caninum, a protein with low sequence identity to NcROP15 or TgROP15 (<15%). Our goal was the detection and molecular characterization of the NCLIV_011700, once homology (with low identity >20%) was observed within the Apicomplexa. The NCLIV_011700 sequence was aligned and compared to the closer apicomplexan homologues (ROP15 from N. caninum, T. gondii, Hammondia hammondi, Cystospores suis), including the predicted domains. In general, the NCLIV_011700 demonstrated low identity with ROP15 of apicomplexan (<20%) and had a ubiquitin domain. On the other side, the NCLIV_011700 homologues were composed of a non-cytoplasmic domain, suggesting different functions between NcROP15 (or homologues) and NCLIV_011700 during the parasite life cycle. Moreover, the NCLIV_011700 was amplified by PCR, ligated to a pET28a plasmid and expressed in Escherichia coli. The recombinant form of NCLIV_011700 was purified in a nickel-Sepharose resin and applied for polyclonal antibody production in mice. The antiserum against NCLIV_011700 (anti-r NCLIV_011700) was used to localize the native form of the protein using Western blot and confocal microscopy. Also, the NCLIV_011700 antiserum partially inhibited the parasite adhesion/invasion process, indicating an active role of the protein in the N. caninum cycle. Thus, the initial NCLIV_011700 characterization will contribute to enlarging the comprehension of N. caninum, aiming at the future development of tools to control the parasite infection/propagation.

BKM120 alters the migration of doublecortin-positive cells in the dentate gyrus of mice

BKM120 is an inhibitor of class I phosphoinositide 3-kinases and its anti-cancer effects have been demonstrated in various solid cancer models. BKM120 is highly brain permeable and has been reported to induce mood disturbances in clinical trials. Therefore, we examined whether BKM120 produces anxiety- and depression-like behaviors in mice, as with patients receiving BKM120 in clinical trials. In this study, repeated BKM120 treatment (2.0 or 5.0mg/kg, i.p., five times at 12-h interval) significantly induced anxiety- and depression-like behaviors in mice. Although abnormal changes in hippocampal neurogenesis have been suggested to, at least in part, associated with the pathogenesis of depression and anxiety, BKM120 did not affect the incorporation of 5-bromo-2'-deoxyuridine or the expression of doublecortin (DCX); however, it significantly enhanced the radial migration of DCX-positive cells in the dentate gyrus. BKM120-induced changes in migration were not accompanied by obvious neuronal damage in the hippocampus. Importantly, BKM120-induced anxiety- and depression-like behaviors were positively correlated with the extent of DCX-positive cell migration. Concomitantly, p-Akt expression was significantly decreased in the dentate gyrus. Moreover, the expression of p-c-Jun N-terminal kinase (JNK), p-DCX, and Ras homolog family member A (RhoA)-GTP decreased significantly, particularly in aberrantly migrated DCX-positive cells. Together, the results suggest that repeated BKM120 treatment enhances the radial migration of DCX-positive cells and induces anxiety- and depression-like behaviors by regulating the activity of Akt, JNK, DCX, and RhoA in the dentate gyrus. It also suggests that the altered migration of adult-born neurons in the dentate gyrus plays a role in mood disturbances.

Dual PI3K/Akt Inhibitors Bearing Coumarin-Thiazolidine Pharmacophores as Potential Apoptosis Inducers in MCF-7 Cells

Breast cancer is the most common malignancy worldwide; therefore, the development of new anticancer agents is essential for improved tumor control. By adopting the pharmacophore hybridization approach, two series of 7-hydroxyl-4-methylcoumarin hybridized with thiosemicarbazone (V–VI) and thiazolidin-4-one moieties (VII–VIII) were prepared. The in vitro anticancer activity was assessed against MCF-7 cells adopting the MTT assay. Nine compounds showed significant cytotoxicity. The most promising compound, VIIb, induced remarkable cytotoxicity (IC₅₀ of 1.03 + 0.05 µM). Further investigations were conducted to explore its pro-apoptotic activity demonstrating S-phase cell cycle arrest. Apoptosis rates following VIIb treatment revealed a 5-fold and 100-fold increase in early and late apoptotic cells, correspondingly. Moreover, our results showed caspase-9 dependent apoptosis induction as manifested by an 8-fold increase in caspase-9 level following VIIb treatment. Mechanistically, VIIb was found to target the PI3K-α/Akt-1 axis, as evidenced by enzyme inhibition assay results reporting significant inhibition of examined enzymes. These findings were confirmed by Western blot results indicating the ability of VIIb to repress levels of Cyclin D1, p-PI3K, and p-Akt. Furthermore, docking studies showed that VIIb has a binding affinity with the PI3K binding site higher than the original ligands X6K. Our results suggest that VIIb has pharmacological potential as a promising anti-cancer compound by the inhibition of the PI3K/Akt axis.

PI3K Signaling in Mechanisms and Treatments of Pulmonary Fibrosis Following Sepsis and Acute Lung Injury

Pulmonary fibrosis is a pathological fibrotic process affecting the lungs of five million people worldwide. The incidence rate will increase even more in the next years due to the long-COVID-19 syndrome, but a resolving treatment is not available yet and usually prognosis is poor. The emerging role of the phosphatidylinositol 3-kinase (PI3K)/AKT signaling in fibrotic processes has inspired the testing of drugs targeting the PI3K/Akt pathway that are currently under clinical evaluation. This review highlights the progress in understanding the role of PI3K/Akt in the development of lung fibrosis and its causative pathological context, including sepsis as well as acute lung injury (ALI) and its consequent acute respiratory distress syndrome (ARDS). We further summarize current knowledge about PI3K inhibitors for pulmonary fibrosis treatment, including drugs under development as well as in clinical trials. We finally discuss how the design of inhaled compounds targeting the PI3K pathways might potentiate efficacy and improve tolerability.

Enhanced in vitro tumoricidal effects of 5-Fluorouracil, thymoquinone, and active vitamin D3 triple therapy against colon cancer cells by attenuating the PI3K/AKT/mTOR pathway

AIMS

This study measured the effects of 5-Fluorouracil (5-FU), calcitriol (VD₃), and/or thymoquinone (TQ) single/dual/triple therapies on cell cycle progression, apoptosis, inhibition of the PI3K/AKT/mTOR pathway, and oxidative stress against colorectal cancer (CRC).

MAIN METHODS

The HT29, SW480 and SW620 cell lines were treated with 5-FU (50 μM), VD₃ (25 μM), and TQ (75 μM), alone or combined for 12 h, prior to cell cycle/apoptosis analyses.

KEY FINDINGS

TQ monotherapy had greater anticancer effects to active VD₃ or 5-FU, revealing higher expression of p21/p27/PTEN/BAX/Cyto-C/Casp-3 and increased levels of total glutathione, with inhibitions in CCND1/CCND3/BCL-2 and PI3K/AKT/mTOR molecules, alongside higher rates of apoptosis in HT29, SW480 and SW620 cells (P < 0.005 for all markers). Additionally, all combination protocols revealed enhanced modulations of the PI3K/PTEN/Akt/mTOR pathway, higher expression of p21/p27/PTEN/BAX/Cyto-C/Casp-3, and better anti-oxidant effects, than the monotherapies. Although TQ/5-FU and TQ/VD₃ co-therapies were better relative to the VD₃/5-FU regimen, the best tumoricidal effects were observed with triple therapy in the HT29 and SW480 cell lines, possibly by boosted attenuations of the PI3K/AKT/mTOR oncogenic pathway. In contrast, TQ single treatment was more effective than the triple therapy regimen in metastatic SW620 cells, suggesting that this protocol would be more useful therapeutically in late-stage CRC.

SIGNIFICANCE

In conclusion, this study is the first to demonstrated enhanced anti-tumorigenic effects for VD₃, TQ, and 5-FU triple therapy against CRC cells and could represent the best strategy for treating early stages of malignancy, whereas TQ monotherapy could be a better approach for treating metastatic forms of the disease.

A novel PI3K inhibitor XH30 suppresses orthotopic glioblastoma and brain metastasis in mice models

Glioblastoma is carcinogenesis of glial cells in central nervous system and has the highest incidence among primary brain tumors. Brain metastasis, such as breast cancer and lung cancer, also leads to high mortality. The available medicines are limited due to blood–brain barrier. Abnormal activation of phosphatidylinositol 3-kinases (PI3K) signaling pathway is prevalent in glioblastoma and metastatic tumors. Here, we characterized a 2-amino-4-methylquinazoline derivative XH30 as a potent PI3K inhibitor with excellent anti-tumor activity against human glioblastoma. XH30 significantly repressed the proliferation of various brain cancer cells and decreased the phosphorylation of key proteins of PI3K signaling pathway, induced cell cycle arrest in G1 phase as well. Additionally, XH30 inhibited the migration of glioma cells and blocked the activation of PI3K pathway by interleukin-17A (IL-17A), which increased the migration of U87MG. Oral administration of XH30 significantly suppressed the tumor growth in both subcutaneous and orthotopic tumor models. XH30 also repressed tumor growth in brain metastasis models of lung cancers. Moreover, XH30 reduced IL-17A and its receptor IL-17RA in vivo. These results indicate that XH30 might be a potential therapeutic drug candidate for glioblastoma migration and brain metastasis.

Hydroxychloroquine synergizes with the PI3K inhibitor BKM120 to exhibit antitumor efficacy independent of autophagy

BACKGROUND

The critical role of phosphoinositide 3-kinase (PI3K) activation in tumor cell biology has prompted massive efforts to develop PI3K inhibitors (PI3Kis) for cancer therapy. However, recent results from clinical trials have shown only a modest therapeutic efficacy of single-agent PI3Kis in solid tumors. Targeting autophagy has controversial context-dependent effects in cancer treatment. As a FDA-approved lysosomotropic agent, hydroxychloroquine (HCQ) has been well tested as an autophagy inhibitor in preclinical models. Here, we elucidated the novel mechanism of HCQ alone or in combination with PI3Ki BKM120 in the treatment of cancer.

METHODS

The antitumor effects of HCQ and BKM120 on three different types of tumor cells were assessed by in vitro PrestoBlue assay, colony formation assay and in vivo zebrafish and nude mouse xenograft models. The involved molecular mechanisms were investigated by MDC staining, LC3 puncta formation assay, immunofluorescent assay, flow cytometric analysis of apoptosis and ROS, qRT-PCR, Western blot, comet assay, homologous recombination (HR) assay and immunohistochemical staining.

RESULTS

HCQ significantly sensitized cancer cells to BKM120 in vitro and in vivo. Interestingly, the sensitization mediated by HCQ could not be phenocopied by treatment with other autophagy inhibitors (Spautin-1, 3-MA and bafilomycin A1) or knockdown of the essential autophagy genes Atg5/Atg7, suggesting that the sensitizing effect might be mediated independent of autophagy status. Mechanistically, HCQ induced ROS production and activated the transcription factor NRF2. In contrast, BKM120 prevented the elimination of ROS by inactivation of NRF2, leading to accumulation of DNA damage. In addition, HCQ activated ATM to enhance HR repair, a high-fidelity repair for DNA double-strand breaks (DSBs) in cells, while BKM120 inhibited HR repair by blocking the phosphorylation of ATM and the expression of BRCA1/2 and Rad51.

CONCLUSIONS

Our study revealed that HCQ and BKM120 synergistically increased DSBs in tumor cells and therefore augmented apoptosis, resulting in enhanced antitumor efficacy. Our findings provide a new insight into how HCQ exhibits antitumor efficacy and synergizes with PI3Ki BKM120, and warn that one should consider the "off target" effects of HCQ when used as autophagy inhibitor in the clinical treatment of cancer.

Digoxin exerts anticancer activity on human nonsmall cell lung cancer cells by blocking PI3K/Akt pathway

Lung cancer remains the leading cause of cancer mortality because of its metastatic potential and high malignancy. The discovery of new applications for old drugs is a shortcut for cancer therapy. We recently investigated the antitumor effect of digoxin, a well-established drug for treating heart failure, against nonsmall cell lung cancer A549 and H1299 cells. Digoxin inhibited the proliferation and colony-forming ability of the two cell lines and arrested the cell cycle at the G0/G1 phase in A549 cells and the G2/M phase in H1299 cells. Mitochondria-mediated apoptosis was induced in A549 cells but not in H1299 cells after treatment with digoxin. Moreover, digoxin inhibited the migration, invasion, adhesion and epithelial–mesenchymal transition of A549 and H1299 cells. Autophagy was induced in both cell lines after treatment with digoxin, with an increase in autophagosome foci. In addition, digoxin inhibited the phosphorylation of Akt, mTOR and p70S6K, signaling molecules of the PI3K/Akt pathway that are known to be involved in tumor cell survival, proliferation, metastasis and autophagy. Our findings suggest that digoxin has the potential to be used for therapy for human nonsmall cell lung cancer, but further evidence is required.

Design, Synthesis, and Structure-Activity Relationship Optimization of Pyrazolopyrimidine Amide Inhibitors of Phosphoinositide 3-Kinase γ (PI3Kγ)

Phosphoinositide-3-kinase γ (PI3Kγ) is highly expressed in immune cells and promotes the production and migration of inflammatory mediators. The inhibition of PI3Kγ has been shown to repolarize the tumor immune microenvironment to a more inflammatory phenotype, thereby controlling immune suppression in cancer. Herein, we report the structure-based optimization of an early lead series of pyrazolopyrimidine isoindolinones, which culminated in the discovery of highly potent and isoform-selective PI3Kγ inhibitors with favorable drug-like properties. X-ray cocrystal structure analysis, molecular docking studies, and detailed structure-activity relationship investigations resulted in the identification of the optimal amide and isoindolinone substituents to achieve a desirable combination of potency, selectivity, and metabolic stability. Preliminary in vitro studies indicate that inhibition of PI3Kγ with compound 56 results in a significant immune response by increasing pro-inflammatory cytokine gene expression in M1 macrophages.

Actein antagonizes colorectal cancer through blocking PI3K/Akt pathways by downregulating IMPDH2

Actein, a triterpene glycoside, isolated from rhizomes of Cimicifuga foetida, was reported to exhibit anticancer effects in vitro and in vivo. However, the effects of actein on colorectal cancer (CRC) remains unclear. As one of the most popular cancers all over the world, CRC ranked third place in both men and women. Recently, we investigated the potential anti-CRC effects of actein and its mechanisms. The Cell counting kit-8 cell proliferation assays, cell cycle detection, apoptosis detection, reactive oxygen species and mitochondrial membrane potential evaluation, western blot, as well as SW480 xenograft mice model were conducted to illustrate the mechanisms of action on anti-CRC effects of actein. Actein could significantly inhibit the human CRC cell lines SW480 and HT-29 proliferation, whereas less antiproliferation effects were found in normal colorectal cell lines HCoEpiC and FHC. Administration of actein resulted in G1 phase cell cycle arrest in both SW480 and HT-29 cells. Moreover, mitochondria-mediated apoptosis was also observed after treatment with actein in SW480 and HT-29 cell lines. Further investigation of mechanisms of action on actein-mediated anti-CRC proliferation effects indicated that the phosphoinositide 3-kinases (PI3K)/Akt pathways were involved. Actein significantly downregulated the phosphorylation of key molecules in PI3K/Akt pathways, including mTOR, glycogen synthesis kinase 3β (GSK-3β), as well as FOXO1. In addition, inosine 5'-monophosphate dehydrogenase type II (IMPDH2) was also observed decreasing in both SW480 and HT-29 cell lines after actein treatment, suggesting that actein may inhibit the PI3K/Akt pathways by decreasing IMPDH2. Finally, our SW480 xenograft model verified the anti-CRC effects and the safety of actein in vivo. Our findings suggest actein is worthy of further investigation as a novel drug candidate for the treatment of CRC.

Taxifolin Targets PI3K and mTOR and Inhibits Glioblastoma Multiforme

Glioblastoma multiforme (GBM), the most common malignant primary brain tumor, has a very poor prognosis. With increasing knowledge of tumor molecular biology, targeted therapies are becoming increasingly integral to comprehensive GBM treatment strategies. mTOR is a key downstream molecule of the PI3K/Akt signaling pathway, integrating input signals from growth factors, nutrients, and energy sources to regulate cell growth and cell proliferation through multiple cellular responses. mTOR/PI3K dual-targeted therapy has shown promise in managing various cancers. Here, we report that taxifolin, a flavanone commonly found in milk thistle, inhibited mTOR/PI3K, promoted autophagy, and suppressed lipid synthesis in GBM. In silico analysis showed that taxifolin can bind to the rapamycin binding site of mTOR and the catalytic site of PI3K (p110α). In in vitro experiments, taxifolin inhibited mTOR and PI3K activity in five different glioma cell lines. Lastly, we showed that taxifolin suppressed tumors in mice; stimulated expression of autophagy-related genes LC3B-II, Atg7, atg12, and Beclin-1; and inhibited expression of fatty acid synthesis-related genes C/EBPα, PPARγ, FABP4, and FAS. Our observations suggest that taxifolin is potentially a valuable drug for treating GBM.

PIK3CA mutation in non-metastatic triple-negative breast cancer as a potential biomarker of early relapse: A case report

BACKGROUND

Currently, the detection of PIK3CA mutations is of special interest in personalized medicine because it is frequently found in triple-negative breast cancer (TNBC). The PI3KCA mutation is an independent negative prognostic factor for survival in metastatic breast cancer, and its prognostic value in liquid biopsy as a biomarker of treatment and early relapse is under investigation, both for metastatic disease and neoadjuvant scenario with curative intent.

CASE SUMMARY

A 54-year-old female patient with TNBC clinical stage IIIA, who, after receiving neoadjuvant chemotherapy (based on anthracyclines and taxanes), surgery, radiotherapy, and adjuvant capecitabine, was detected with a PI3KCA mutation in tissue and peripheral blood (ctDNA in liquid biopsy). After 10 mo, the patient had disease relapse of left cervical node disease.

CONCLUSION

The detection of PIK3CA mutation in TNBC after neoadjuvant treatment might be associated with early relapse or rapid disease progression.

VS-5584, a PI3K/mTOR dual inhibitor, exerts antitumor effects on neuroblastomas in vitro and in vivo

BACKGROUND

The phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway is closely related to oncogenesis. PI3K/mTOR inhibitors are considered capable of counteracting the feedback mechanisms within the pathway. In this study, we investigated the antitumor effects of VS-5584, an orally administered PI3K/mTOR dual inhibitor, on neuroblastomas.

METHODS

The effects of VS-5584 on proliferation, cell cycle distribution, and related signaling molecules were examined in neuroblastoma cells using the (3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide)-based colorimetric assay, flow cytometry, and western blotting, respectively. Nude mice were subcutaneously inoculated with human neuroblastoma cells, followed by VS-5584 treatment for two weeks. Tumor growth was tracked and tumor tissues were subjected to immunohistochemical investigations.

RESULTS

In neuroblastoma cells, VS-5584 significantly inhibited proliferation and induced G0/G1 cell cycle arrest. Additionally, VS-5584 decreased the expression of phospho-S6 kinase 1 (p-S6K1), p-retinoblastoma protein, p-cyclin-dependent kinase 2, and cyclin E1, and increased the expression of p21 and p27 in neuroblastoma cells. In mice, VS-5584 significantly suppressed tumor growth in neuroblastomas and downregulated the expression of p-mTOR and p-S6K1 in tumor tissues.

CONCLUSIONS

VS-5584 blocks the PI3K/mTOR pathway, induces a G0/G1 cell cycle arrest, and exerts antitumor effects on neuroblastomas both in vitro and in vivo.

Synthesis and biological evaluation of novel purinyl quinazolinone derivatives as PI3Kδ-specific inhibitors for the treatment of hematologic malignancies

Phosphatidylinositol 3-kinases (PI3Ks) mediate intracellular signal transduction. Aberrant PI3K signaling is associated with oncogenesis and disease progression in solid tumors and hematologic malignancies. Idelalisib (1), a first-in-class PI3Kδ inhibitor for the treatment of hematologic malignancies, was developed, but its sales were limited by black box warnings due to unexpected adverse effects. Therefore, to overcome these adverse events, various quinazolinone derivatives were synthesized and evaluated in vitro based on their inhibitory activity against the PI3K enzyme and the viability of cell lines such as MOLT and SUDHL. Among them, 6f (IC₅₀ = 0.39 nM) and 6m (IC₅₀ = 0.09 nM) showed excellent enzyme activity, and 6m displayed an approximately four-fold higher selectivity for PI3Kγ/δ compared with Idelalisib (1). Furthermore, in vivo PK experiments with 6f and 6m revealed that 6f (AUC_last = 81.04 h*ng/mL, C_max = 18.34 ng/mL, T_max = 0.5 h, t_1/2 = 10.2 h in 1 mpk dose) had improved PK compared with 1. Finally, further experiments will be conducted with 6f selected as a candidate, and the potential for it to be developed as a treatment with good efficacy for hematologic malignancies will be determined.

Targeting the PI3K/AKT/mTOR Signaling Pathway in Lung Cancer: An Update Regarding Potential Drugs and Natural Products

Lung cancer is one of the most common cancers and has a high mortality rate. Due to its high incidence, the clinical management of the disease remains a major challenge. Several reports have documented a relationship between the phosphatidylinositol-3-kinase (PI3K)/ protein kinase B (AKT)/ mammalian target of rapamycin (mTOR) pathway and lung cancer. The recognition of this pathway as a notable therapeutic target in lung cancer is mainly due to its central involvement in the initiation and progression of the disease. Interest in using natural and synthetic medications to target these signaling pathways has increased in recent years, with promising results in vitro, in vivo, and in clinical trials. In this review, we focus on the current understanding of PI3K/AKT/mTOR signaling in tumor development. In addition to the signaling pathway, we highlighted the therapeutic potential of recently developed PI3K/AKT/mTOR inhibitors based on preclinical and clinical trials.

Lansoprazole Alone or in Combination With Gefitinib Shows Antitumor Activity Against Non-small Cell Lung Cancer A549 Cells in vitro and in vivo

Lansoprazole (Lpz) is an FDA-approved proton pump inhibitor (PPI) drug for the therapy of acid-related diseases. Aiming to explore the new application of old drugs, we recently investigated the antitumor effect of Lpz. We demonstrated that the PPI Lpz played a tumor suppressive role in non-small cell lung cancer (NSCLC) A549 cells. Mechanistically, Lpz induced apoptosis and G0/G1 cell cycle arrest by inhibiting the activation of signal transducer and activator of transcription (Stat) 3 and the phosphoinositide 3-kinase (PI3K)/Akt and Raf/ERK pathways. In addition, Lpz inhibited autophagy by blocking the fusion of autophagosomes with lysosomes. Furthermore, Lpz in combination with gefitinib (Gef) showed a synergistic antitumor effect on A549 cells, with enhanced G0/G1 cell cycle arrest and apoptosis. The combination inhibited Stat3 phosphorylation, PI3K/Akt and Raf/ERK signaling, affecting cell cycle-related proteins such as p-Rb, cyclin D1 and p27, as well as apoptotic proteins such as Bax, Bcl-2, caspase-3, and poly (ADP-ribose) polymerase (PARP). In vivo, coadministration with Lpz and Gef significantly attenuated the growth of A549 nude mouse xenograft models. These findings suggest that Lpz might be applied in combination with Gef for NSCLC therapy, but further evidence is required.

Phosphoinositide 3-Kinase (PI3K) Reactive Oxygen Species (ROS)-Activated Prodrug in Combination with Anthracycline Impairs PI3K Signaling, Increases DNA Damage Response and Reduces Breast Cancer Cell Growth

RIDR-PI-103 is a novel reactive oxygen species (ROS)-induced drug release prodrug with a self-cyclizing moiety linked to a pan-PI3K inhibitor (PI-103). Under high ROS, PI-103 is released in a controlled manner to inhibit PI3K. The efficacy and bioavailability of RIDR-PI-103 in breast cancer remains unexplored. Cell viability of RIDR-PI-103 was assessed on breast cancer cells (MDA-MB-231, MDA-MB-361 and MDA-MB-453), non-tumorigenic MCF10A and fibroblasts. Matrigel colony formation, cell proliferation and migration assays examined the migratory properties of breast cancers upon treatment with RIDR-PI-103 and doxorubicin. Western blots determined the effect of doxorubicin ± RIDR-PI-103 on AKT activation and DNA damage response. Pharmacokinetic (PK) studies using C57BL/6J mice determined systemic exposure (plasma concentrations and overall area under the curve) and T1/2 of RIDR-PI-103. MDA-MB-453, MDA-MB-231 and MDA-MB-361 cells were sensitive to RIDR-PI-103 vs. MCF10A and normal fibroblast. Combination of doxorubicin and RIDR-PI-103 suppressed cancer cell growth and proliferation. Doxorubicin with RIDR-PI-103 inhibited p-AktS473, upregulated p-CHK1/2 and p-P53. PK studies showed that ~200 ng/mL (0.43 µM) RIDR-PI-103 is achievable in mice plasma with an initial dose of 20 mg/kg and a 10 h T1/2. (4) The prodrug RIDR-PI-103 could be a potential therapeutic for treatment of breast cancer patients.

ABCB1 and ABCG2 restricts the efficacy of gedatolisib (PF-05212384), a PI3K inhibitor in colorectal cancer cells

Background

Overexpression of ABC transporters is a big challenge on cancer therapy which will lead cancer cells resistance to a series of anticancer drugs. Gedatolisib is a dual PI3K and mTOR inhibitor which is under clinical evaluation for multiple types of malignancies, including colorectal cancer. The growth inhibitory effects of gedatolisib on colorectal cancer cells have been specifically studied. However, the role of ABC transporters on gedatolisib resistance remained unclear. In present study, we illustrated the role of ABC transporters on gedatolisib resistance in colorectal cancer cells.

Methods

Cell viability investigations of gedatolisib on colorectal cancer cells were determined by MTT assays. The verapamil and Ko143 reversal studies were determined by MTT assays as well. ABCB1 and/or ABCG2 siRNA interference assays were conducted to verify the role of ABCB1- and ABCG2-overexpression on gedatolisib resistance. The accumulation assays of gedatolisib were conducted using tritium-labeled paclitaxel and mitoxantrone. The effects of gedatolisib on ATPase activity of ABCB1 or ABCG2 were conducted using PREDEASY ATPase Kits. The expression level of ABCB1 and ABCG2 after gedatolisib treatment were conducted by Western blotting and immunofluorescence assays. The well-docked position of gedatolisib with crystal structure of ABCB1 and ABCG2 were simulated by Autodock vina software. One-way ANOVA was used for the statistics analysis.

Results

Gedatolisib competitively increased the accumulation of tritium-labeled substrate-drugs in both ABCB1- and ABCG2-overexpression colorectal cancer cells. Moreover, gedatolisib significantly increased the protein expression level of ABCB1 and ABCG2 in colorectal cancer cells. In addition, gedatolisib remarkably simulated the ATPase activity of both ABCB1 and ABCG2, suggesting that gedatolisib is a substrate drug of both ABCB1 and ABCG2 transporters. Furthermore, a gedatolisib-resistance colorectal cancer cell line, SW620/GEDA, was selected by increasingly treatment with gedatolisib to SW620 cells. The SW620/GEDA cell line was proved to resistant to gedatolisib and a series of chemotherapeutic drugs, except cisplatin. The ABCB1 and ABCG2 were observed overexpression in SW620/GEDA cell line.

Conclusions

These findings suggest that overexpression of ABCB1 and ABCG2 may restrict the efficacy of gedatolisib in colorectal cancer cells, while co-administration with ABC transporter inhibitors may improve the potency of gedatolisib.

The Role of mTOR Signaling as a Therapeutic Target in Cancer

The aim of this review was to summarize current available information about the role of phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling in cancer as a potential target for new therapy options. The mTOR and PI3K/AKT/mTORC1 (mTOR complex 1) signaling are critical for the regulation of many fundamental cell processes including protein synthesis, cell growth, metabolism, survival, catabolism, and autophagy, and deregulated mTOR signaling is implicated in cancer, metabolic dysregulation, and the aging process. In this review, we summarize the information about the structure and function of the mTOR pathway and discuss the mechanisms of its deregulation in human cancers including genetic alterations of PI3K/AKT/mTOR pathway components. We also present recent data regarding the PI3K/AKT/mTOR inhibitors in clinical studies and the treatment of cancer, as well the attendant problems of resistance and adverse effects.

Raloxifene, identified as a novel LSD1 inhibitor, suppresses the migration of renal cell carcinoma

Aim: As an important epigenetic modulator, histone lysine-specific demethylase 1 (LSD1) has been proved to be associated with the progression of renal cell carcinoma (RCC). Discovering novel LSD1 inhibitors offers therapeutic potential for RCC treatment. Methods & Results: We identified raloxifene as a novel LSD1 inhibitor (IC₅₀ = 2.08 μM) through small compound library screening. Molecular docking indicated raloxifene might bind LSD1 in the flavin adenine dinucleotide (FAD) binding cavity in a reversible manner. Cell viability and migration assays showed raloxifene could suppress the proliferation and migration of RCC cells bearing overexpressed LSD1. Conclusion: Our findings indicated that LSD1 might be a promising therapeutic target for RCC and that raloxifene could serve as a lead compound for further anti-RCC metastasis drug discovery.