LARP1, an RNA-binding protein, participates in ovarian cancer cell survival by regulating mitochondrial oxidative phosphorylation in response to the influence of the PI3K/mTOR pathway.

Targeting the PI3K/mTOR pathway and modulating mitochondrial adaptation is expected to be a critical approach for cancer therapy. Although the regulation of mitochondria by the PI3K/mTOR pathway has been investigated, it is not well understood due to the complexity of its regulatory mechanisms. RNA-binding proteins (RBPs) selectively regulate gene expression through post-transcriptional modulation, playing a key role in cancer progression. LARP1, a downstream RBP of the mTOR pathway, is involved in mitochondria-mediated BCL-2 cell survival. Therefore, exploring the involvement of LARP1 in PI3K/mTOR-mediated translational regulation of mitochondria-associated proteins in ovarian cancer cells could help elucidate the role of mitochondria in the PI3K/mTOR pathway. We found that, unlike SKOV3 cells, the mitochondrial function of A2780 cells was not affected, which were insensitive to the dual PI3K/mTOR inhibitor PKI-402, suggesting that cell survival may be related to mitochondrial function. Knockdown of the LARP1 gene after PKI-402 treatment resulted in impaired mitochondrial function in A2780 cells, possibly due to decreased mRNA stability and reduced protein translation of the mitochondrial transcription initiation factor, TFB2M, and the respiratory chain complex II subunit, SDHB. LARP1 affects protein translation by binding to TFB2M mRNA, regulating mitochondrial DNA-encoded genes, or indirectly regulating the nuclear DNA-encoded SDHB gene, ultimately interfering with mitochondrial oxidative phosphorylation and leading to apoptosis. Therefore, LARP1 may be an important mediator in the PI3K/mTOR pathway for regulating mRNA translation and mitochondrial function. Targeting RBPs such as LARP1 downstream of the mTOR pathway may provide new insights and potential therapeutic approaches for ovarian cancer treatment.

Exploring the effect of Gouqi Nuzhen Liuhe decoction on the PI3K/mTOR signaling pathway for premature ovarian insufficiency based on system pharmacology.

Objective: To explore the effect of Gouqi Nuzhen Liuhe Decoction (GNLHD) on the PI3K/mTOR Signaling Pathway for Premature Ovarian Insufficiency (POI) based on system pharmacology. Methods: First, the system pharmacology approach was used to predict the mechanism of GNLHD. Then, mice were randomly divided into model group, positive group, GNLHD high-dose group, GNLHD medium-dose group, and GNLHD low-dose group. Hematoxylin-eosin (HE) staining was used to observe the pathological changes of ovarian tissue under light microscope. The expression levels of estradiol (E2), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were detected by enzyme-linked immunosorbent assay. The expressions of PI3K, AKT1 and mTOR proteins in ovarian tissue were detected by immunohistochemistry. Results: The results of system pharmacology showed that GNLHD may regulate biological processes and signaling pathways such as: reproductive structure development, reproductive system development, Oocyte meiosis and so on. Compared with the model group, the levels of E2 in the GNLHD group were increased, and the levels of FSH and LH were decreased (P < 0.05). Compared with the model group, the number of mature follicles in the GNLHD group was significantly increased, the number of atretic follicles was relatively decreased, and the expressions of PI3K, AKT1, and MTOR proteins in the GNLHD group were significantly increased (P < 0.05). Conclusion: GNLHD may improve the ovarian function of POI mice by affecting the expression of PI3K, AKT1 and mTOR proteins, promote the growth and development of follicles, increase the E2 level, reduce FSH and LH level, and maintain the stability of the ovarian internal environment.

Interplay between WNT/PI3K-mTOR axis and the microbiota in APC-driven colorectal carcinogenesis: data from a pilot study and possible implications for CRC prevention.

BACKGROUND: Wnt/ß-catenin signalling impairment accounts for 85% of colorectal cancers (CRCs), including sporadic and familial adenomatous polyposis (FAP) settings. An altered PI3K/mTOR pathway and gut microbiota also contribute to CRC carcinogenesis. We studied the interplay between the two pathways and the microbiota composition within each step of CRC carcinogenesis. METHODS: Proteins and target genes of both pathways were analysed by RT-qPCR and IHC in tissues from healthy faecal immunochemical test positive (FIT+, n = 17), FAP (n = 17) and CRC (n = 15) subjects. CRC-related mutations were analysed through NGS and Sanger. Oral, faecal and mucosal microbiota was profiled by 16 S rRNA-sequencing. RESULTS: We found simultaneous hyperactivation of Wnt/ß-catenin and PI3K/mTOR pathways in FAP-lesions compared to CRCs. Wnt/ß-catenin molecular markers positively correlated with Clostridium_sensu_stricto_1 and negatively with Bacteroides in FAP faecal microbiota. Alistipes, Lachnospiraceae, and Ruminococcaceae were enriched in FAP stools and adenomas, the latter also showing an overabundance of Lachnoclostridium, which positively correlated with cMYC. In impaired-mTOR-mutated CRC tissues, p-S6R correlated with Fusobacterium and Dialister, the latter also confirmed in the faecal-ecosystem. CONCLUSIONS: Our study reveals an interplay between Wnt/ß-catenin and PI3K/mTOR, whose derangement correlates with specific microbiota signatures in FAP and CRC patients, and identifies new potential biomarkers and targets to improve CRC prevention, early adenoma detection and treatment.

Pathogenesis of Endometriosis and Endometriosis-Associated Cancers.

Endometriosis is a hormone-dependent, chronic inflammatory condition that affects 5-10% of reproductive-aged women. It is a complex disorder characterized by the growth of endometrial-like tissue outside the uterus, which can cause chronic pelvic pain and infertility. Despite its prevalence, the underlying molecular mechanisms of this disease remain poorly understood. Current treatment options are limited and focus mainly on suppressing lesion activity rather than eliminating it entirely. Although endometriosis is generally considered a benign condition, substantial evidence suggests that it increases the risk of developing specific subtypes of ovarian cancer. The discovery of cancer driver mutations in endometriotic lesions indicates that endometriosis may share molecular pathways with cancer. Moreover, the application of single-cell and spatial genomics, along with the development of organoid models, has started to illuminate the molecular mechanisms underlying disease etiology. This review aims to summarize the key genetic mutations and alterations that drive the development and progression of endometriosis to malignancy. We also review the significant recent advances in the understanding of the molecular basis of the disorder, as well as novel approaches and in vitro models that offer new avenues for improving our understanding of disease pathology and for developing new targeted therapies.

Repositioning of baricitinib for management of memory impairment in ovariectomized/D-galactose treated rats: A potential role of JAK2/STAT3-PI3K/AKT/mTOR signaling pathway.

AIMS: Neuroinflammation plays a pivotal role in amyloid ß (Aß) plaques formation which is among the hallmarks of Alzheimer's disease (AD). The present study investigated the potential therapeutic effects of baricitinib (BAR), a selective JAK2/ STAT3 inhibitor, in ovariectomized/ D-galactose (OVX/D-gal) treated rats as a model for AD. MAIN METHODS: To induce AD, adult female rats (130-180 g) underwent bilateral ovariectomy and were injected daily with 150 mg/kg, i.p. D-gal for 8 consecutive weeks. BAR (10 and 50 mg/kg/day) was then given orally for 14 days. KEY FINDINGS: BAR in a dose-dependent effect mitigated OVX/D-gal-induced aberrant activation of JAK2/STAT3 signaling pathway resulting in significant decreases in the expression of p-JAK 2, and p-STAT3 levels, along with deactivating AKT/PI3K/mTOR signaling as evidenced by deceased protein expression of p-AKT, p-PI3K, and p-mTOR. As a result, neuroinflammation was diminished as evidenced by decreased NF-κß, TNF-α, and IL-6 levels. Moreover, oxidative stress biomarkers levels as iNOS, and MDA were reduced, whereas GSH was increased by BAR. BAR administration also succeeded in reverting histopathological alterations caused by OVX/D-gal, increased the number of intact neurons (detected by Nissl stain), and diminished astrocyte hyperactivity assessed as GFAP immunoreactivity. Finally, treatment with BAR diminished the levels of Aß. These changes culminated in enhancing spatial learning and memory in Morris water maze, and novel object recognition test. SIGNIFICANCE: BAR could be an effective therapy against neuroinflammation, astrogliosis and cognitive impairment induced by OVX/ D-gal where inhibiting JAK2/STAT3- AKT/PI3K/mTOR seems to play a crucial role in its beneficial effect.

Dual blockage of PI3K-mTOR and FGFR induced autophagic cell death in cholangiocarcinoma cells.

Purpose: To assess the impact of concurrent inhibition of the FGFR and PI3K/mTOR signaling pathways on oncogenic characteristics in cholangiocarcinoma (CCA) cells, including proliferation, autophagy, and cell death. Materials and methods: KKU-213A, KKU-100, and KKU-213C cells were treated with either infigratinib or PKI-402 alone or in combination. Cell viability and cell death were evaluated using the sulforhodamine B (SRB) assay and acridine orange/ethidium bromide (AO/EB) staining. Cell cycle progression and apoptotic cell death were analyzed by flow cytometry. Western blotting was performed to assess the expression of proteins involved in cell cycle regulation and autophagy. Additionally, AO staining was employed to assess autophagic induction. Results: The combination of infigratinib and PKI-402 showed a remarked synergistic suppression in cell viability in both CCA cell lines compared to treatment with single inhibitors. This antiproliferative effect was associated with cell cycle arrest in the G2-M phase and a decrease in the expression of cyclin A and cyclin B1 in CCA cells. Furthermore, the combination treatment induced apoptotic cell death to a greater extent than treatment with a single inhibitor. Infigratinib enhanced the induction of autophagy by PKI-402, as evidenced by marked increases of autophagic vacuoles stained acridine orange, levels of LC3B-II and suppression of levels of p-mTOR and. Notably, inhibition of autophagic flux by chloroquine prevented cell death induced by the combination treatment. Conclusions: This study demonstrated that concurrent inhibition of the key FGFR/PI3K/mTOR pathways in CCA carcinogenesis enhances the suppression of CCA cells. The present findings indicate potential clinical implications for using combination treatment modalities in CCA therapy.

PI3K/mTOR inhibition induces tumour microenvironment remodelling and sensitises pS6high uterine leiomyosarcoma to PD-1 blockade.

BACKGROUND: Uterine leiomyosarcomas (uLMS) are aggressive tumours with poor prognosis and limited treatment options. Although immune checkpoint blockade (ICB) has proven effective in some 'challenging-to-treat' cancers, clinical trials showed that uLMS do not respond to ICB. Emerging evidence suggests that aberrant PI3K/mTOR signalling can drive resistance to ICB. We therefore explored the relevance of the PI3K/mTOR pathway for ICB treatment in uLMS and explored pharmacological inhibition of this pathway to sensitise these tumours to ICB. METHODS: We performed an integrated multiomics analysis based on TCGA data to explore the correlation between PI3K/mTOR dysregulation and immune infiltration in 101 LMS. We assessed response to PI3K/mTOR inhibitors in immunodeficient and humanized uLMS patient-derived xenografts (PDXs) by evaluating tumour microenvironment modulation using multiplex immunofluorescence. We explored response to single-agent and a combination of PI3K/mTOR inhibitors with PD-1 blockade in humanized uLMS PDXs. We mapped intratumoural dynamics using single-cell RNA/TCR sequencing of serially collected biopsies. RESULTS: PI3K/mTOR over-activation (pS6high) associated with lymphocyte depletion and wound healing immune landscapes in (u)LMS, suggesting it contributes to immune evasion. In contrast, PI3K/mTOR inhibition induced profound tumour microenvironment remodelling in an ICB-resistant humanized uLMS PDX model, fostering adaptive anti-tumour immune responses. Indeed, PI3K/mTOR inhibition induced macrophage repolarisation towards an anti-tumourigenic phenotype and increased antigen presentation on dendritic and tumour cells, but also promoted infiltration of PD-1+ T cells displaying an exhausted phenotype. When combined with anti-PD-1, PI3K/mTOR inhibition led to partial or complete tumour responses, whereas no response to single-agent anti-PD-1 was observed. Combination therapy reinvigorated exhausted T cells and induced clonal hyper-expansion of a cytotoxic CD8+ T-cell population supported by a CD4+ Th1 niche. CONCLUSIONS: Our findings indicate that aberrant PI3K/mTOR pathway activation contributes to immune escape in uLMS and provides a rationale for combining PI3K/mTOR inhibition with ICB for the treatment of this patient population.

PUMC-MB1 is a novel group 3 medulloblastoma preclinical model, sensitive to PI3K/mTOR dual inhibitor.

PURPOSE: Medulloblastoma (MB), a common and heterogeneous posterior fossa tumor in pediatric patients, presents diverse prognostic outcomes. To advance our understanding of MB's intricate biology, the development of novel patient tumor-derived culture MB models with necessary data is still an essential requirement. METHODS: We continuously passaged PUMC-MB1 in vitro in order to establish a continuous cell line. We examined the in vitro growth using Cell Counting Kit-8 (CCK-8) and in vivo growth with subcutaneous and intracranial xenograft models. The xenografts were investigated histopathologically with Hematoxylin and Eosin (HE) staining and immunohistochemistry (IHC). Concurrently, we explored its molecular features using Whole Genome Sequencing (WGS), targeted sequencing, and RNA sequecing. Guided by bioinformatics analysis, we validated PUMC-MB1's drug sensitivity in vitro and in vivo. RESULTS: PUMC-MB1, derived from a high-risk MB patient, displayed a population doubling time (PDT) of 48.18 h and achieved 100% tumor growth in SCID mice within 20 days. HE and Immunohistochemical examination of the original tumor and xenografts confirmed the classification of PUMC-MB1 as a classic MB. Genomic analysis via WGS revealed concurrent MYC and OTX2 amplifications. The RNA-seq data classified it within the Group 3 MB subgroup, while according to the WHO classification, it fell under the Non-WNT/Non-SHH MB. Comparative analysis with D283 and D341med identified 4065 differentially expressed genes, with notable enrichment in the PI3K-AKT pathway. Cisplatin, 4-hydroperoxy cyclophosphamide/cyclophosphamide, vincristine, and dactolisib (a selective PI3K/mTOR dual inhibitor) significantly inhibited PUMC-MB1 proliferation in vitro and in vivo. CONCLUSIONS: PUMC-MB1, a novel Group 3 (Non-WNT/Non-SHH) MB cell line, is comprehensively characterized for its growth, pathology, and molecular characteristics. Notably, dactolisib demonstrated potent anti-proliferative effects with minimal toxicity, promising a potential therapeutic avenue. PUMC-MB1 could serve as a valuable tool for unraveling MB mechanisms and innovative treatment strategies.

Lactobacillus rhamnosus HN001 facilitates the efficacy of dual PI3K/mTOR inhibition prolonging cardiac transplant survival and enhancing antitumor effect.

Solid organ transplantation is a crucial treatment for patients who have reached the end stage of heart, lung, kidney, or liver failure. However, the likelihood of developing cancer post-transplantation increases. Additionally, primary malignant tumors remain a major obstacle to the long-term survival of transplanted organs. Therefore, it is essential to investigate effective therapies that can boost the immune system's ability to combat cancer and prevent allograft rejection. We established a mouse orthotopic liver tumor model and conducted allogeneic heterotopic heart transplantation. Various treatments were administered, and survival curves were generated using the Kaplan-Meier method. We also collected graft samples and measured inflammatory cytokine levels in the serum using an inflammatory array. The specificity of the histochemical techniques was tested by staining sections. We administered a combination therapy of phosphoinositide 3-kinase/mammalian target of rapamycin (PI3K/mTOR) dual inhibitor BEZ235 and Lactobacillus rhamnosus HN001 to primary liver cancer model mice with cardiac allografts. Consistent with our prior findings, L. rhamnosus HN001 alleviated the intestinal flora imbalance caused by BEZ235. Our previous research confirmed that the combination of BEZ235 and L. rhamnosus HN001 significantly prolonged cardiac transplant survival. IMPORTANCE: We observed that the combination of phosphoinositide 3-kinase/mammalian target of rapamycin (PI3K/mTOR) dual inhibitor BEZ235 and Lactobacillus rhamnosus HN001 notably prolonged cardiac transplant survival while also inhibiting the progression of primary liver cancer. The combination therapy was efficacious in treating antitumor immunity and allograft rejection, as demonstrated by the efficacy results. We also found that this phenomenon was accompanied by the regulation of inflammatory IL-6 expression. Our study presents a novel and effective therapeutic approach to address antitumor immunity and prevent allograft rejection.

A Phase I Study of the Oral Dual-Acting Pan-PI3K/mTOR Inhibitor Bimiralisib in Patients with Advanced Solid Tumors.

BACKGROUND: Bimiralisib is a pan-PI3K/mTOR inhibitor demonstrating antitumor efficacy in preclinical models. The objectives of this study were to identify a maximum tolerated dose (MTD), pharmacokinetics (PK), a dosing schedule, and adverse events (AEs) in patients with advanced solid tumors. PATIENTS AND METHODS: Patients received oral bimiralisib to determine the MTD of one continuous (once daily) and two intermittent schedules (A: Days 1, 2 weekly; B: Days 1, 4 weekly) until progression or unacceptable AEs occurred. RESULTS: The MTD for the continuous schedule was 80 mg, with grade three fatigue as the dose-limiting toxicity (DLT). No MTD was reached with intermittent schedules, with only one DLT in schedule B. PK analysis suggested that 140 mg (schedule A) was within the biologically active dose range and was selected for further exploration. The most frequent treatment-emergent AEs were hyperglycemia (76.2%) in the continuous schedule, and nausea (56-62.5%) in schedules A and B. The most frequent treatment-emergent > grade three AE for all schedules combined was hyperglycemia (28.6%, continuous schedule; 12.0%, schedule A; 12.5%, schedule B). There was one partial response in a head and neck squamous cancer patient with a NOTCH1T1997M mutation. CONCLUSIONS: Bimiralisib demonstrated a manageable AE profile consistent with this compound class. Intermittent schedules had fewer > grade three AEs, while also maintaining favorable PK profiles. Intermittent schedule A is proposed for further development in biomarker-selected patient populations.

The emerging role of noncoding RNAs in the PI3K/AKT/mTOR signalling pathway in breast cancer.

Breast cancer persists as a major problem for the world's healthcare, thus it is essential to fully understand the complex molecular processes that cause its growth and development. ncRNAs had been discovered to serve critical roles in a variety of cellular functions, including the regulation of signalling pathways. Within different pathways, the AKT/PI3K/mTOR signalling cascade has received a lot of interest because of its role in cancer. A complex interaction between ncRNAs, notably miRNAs, lncRNAs, and circRNAs, and the AKT/PI3K/mTOR signalling pathway exerts both oncogenic and tumor-suppressive activities by targeting critical components of the pathway directly or indirectly. Through miRNA-mediated post-transcriptional regulation, lncRNA-guided chromatin remodelling, and circRNA sequestration, ncRNAs modulate the activity of PI3K, AKT, and mTOR, influencing cell proliferation, survival, and metastasis. Furthermore, ncRNAs can serve as promising biomarkers for breast cancer prognosis, diagnosis, and treatment response, as their dysregulation is commonly observed in breast cancer patients. Harnessing the potential of ncRNAs as therapeutic targets or tools for restoring pathway homeostasis holds promise for innovative treatment strategies in breast cancer. Understanding the intricate regulatory networks orchestrated by ncRNAs in this context may pave the way for novel diagnostic approaches, therapeutic interventions, and a deeper comprehension of breast cancer's molecular landscape, ultimately improving patient outcomes. This abstract underscores the emerging significance of ncRNAs in the AKT/PI3K/mTOR signaling pathway in breast cancer.

Cordyceps cicadae ameliorates inflammatory responses, oxidative stress, and fibrosis by targeting the PI3K/mTOR-mediated autophagy pathway in the renal of MRL/lpr mice.

BACKGROUND: The vast majority of systemic lupus erythematosus patients develop lupus nephritis (LN) with severe renal manifestations, such as inflammatory responses, oxidative stress, and fibrosis. The purpose of this research was to investigate Cordyceps cicadae as a potential therapeutic target for treating inflammatory responses, oxidative stress, and fibrosis in LN. METHODS: The effects of C. cicadae on lupus symptoms in mice with LN were determined. MRL/lpr mice were treated with C. cicadae (4 g/kg/day, i.e., CC group, n = 8) or an equal volume of saline (model group, n = 8), and MRL/MP mice were treated with an equal volume of saline (control group, n = 8). Renal function indices, renal pathology, inflammatory markers, oxidative stress markers, and renal interstitial fibrosis levels were evaluated after C. cicadae treatment. Western blot analysis was performed to investigate the effect of C. cicadae on the expression of fibrosis biomarkers and the phosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin (mTOR)-mediated autophagy pathway in the renal tissues of mice. RESULTS: C. cicadae ameliorated renal lesions, the inflammatory response, and oxidative stress damage in MRL/lpr mice. C. cicadae treatment inhibited renal fibrosis (16.31 ± 4.16 vs. 31.25 ± 5.61) and downregulated the expression of the fibrosis biomarkers alpha-smooth muscle actin, fibronectin, and collagen I (COL I) in the kidneys of MRL/lpr mice. In addition, further research showed that the PI3K/mTOR-mediated autophagy pathway was involved in C. cicadae-mediated effects on renal fibrosis in MRL/lpr mice. Furthermore, the therapeutic effect of C. cicadae on repairing renal fibrosis and damage in MRL/lpr mice was abolished by the PI3K agonist 740 Y-P. CONCLUSIONS: The findings of the present research showed that C. cicadae could alleviate inflammatory responses, oxidative stress, and fibrosis in the renal tissues of mice with LN by targeting the PI3K/mTOR-mediated autophagy pathway.

Correlation of PTEN signaling pathway and miRNA in breast cancer.

Breast cancer (BC) is one of the most common cancers among women and can be fatal if not diagnosed and treated on time. Various genetic and environmental factors play a significant role in the development and progression of BC. Within the body, different signaling pathways have been identified that contribute to cancer progression, or conversely, cancer prevention. Phosphatase and tensin homolog (PTEN) is one of the proteins that prevent cancer by inhibiting the oncogenic PI3K/Akt/mTOR signaling pathway. MicroRNAs (miRNAs) are molecules with about 18 to 28 base pairs, which regulate about 30% of human genes after transcription. miRNAs play a key role in the progression or prevention of cancer through different signaling pathway and mechanisms, e.g., apoptosis, angiogenesis, and proliferation. miRNAs, which are upstream mediators of PTEN, can reinforce or suppress the effect of PTEN signaling on BC cells, and suppressing the PTEN signaling, linked to weakness of the cancer cells to chemotherapeutic drugs. However, the precise mechanism and function of miRNAs on PTEN in BC are not yet fully understood. Therefore, in the present study, has been focused on miRNAs regulating PTEN function in BC.

Cyclometalated ruthenium complexes overcome cisplatin resistance through PI3K/mTOR/Nrf2 signaling pathway.

Currently, cisplatin resistance remains a primary clinical obstacle in the successful treatment of non-small cell lung cancer. Here, we designed, synthesized, and characterized two novel cyclometalated Ru(II) complexes, [Ru(bpy)2(1-Ph-7-OCH3-IQ)] (PF6) (bpy = 2,2'-bipyridine, IQ = isoquinoline, RuIQ7)and [Ru(bpy)2(1-Ph-6,7-(OCH3)2-IQ)] (PF6) (RuIQ8). As experimental controls, we prepared complex [Ru(bpy)2(1-Ph-IQ)](PF6) (RuIQ6) lacking a methoxy group in the main ligand. Significantly, complexes RuIQ6-8 displayed higher in vitro cytotoxicity when compared to ligands, precursor cis-[Ru(bpy)2Cl2], and clinical cisplatin. Mechanistic investigations revealed that RuIQ6-8 could inhibit cell proliferation by downregulating the phosphorylation levels of Akt and mTOR proteins, consequently affecting the rapid growth of human lung adenocarcinoma cisplatin-resistant cells A549/DDP. Moreover, the results from qRT-PCR demonstrated that these complexes could directly suppress the transcription of the NF-E2-related factor 2 gene, leading to the inhibition of downstream multidrug resistance-associated protein 1 expression and effectively overcoming cisplatin resistance. Furthermore, the relationship between the chemical structures of these three complexes and their anticancer activity, ability to induce cell apoptosis, and their efficacy in overcoming cisplatin resistance has been thoroughly examined and discussed. Notably, the toxicity test conducted on zebrafish embryos indicated that the three Ru-IQ complexes displayed favorable safety profiles. Consequently, the potential of these developed compounds as innovative therapeutic agents for the efficient and low-toxic treatment of NSCLC appears highly promising.

PI3K/Akt/mTOR Signaling Pathway in Blood Malignancies-New Therapeutic Possibilities.

Blood malignancies remain a therapeutic challenge despite the development of numerous treatment strategies. The phosphatidylinositol-3 kinase (PI3K)/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathway plays a central role in regulating many cellular functions, including cell cycle, proliferation, quiescence, and longevity. Therefore, dysregulation of this pathway is a characteristic feature of carcinogenesis. Increased activation of PI3K/Akt/mTOR signaling enhances proliferation, growth, and resistance to chemo- and immunotherapy in cancer cells. Overactivation of the pathway has been found in various types of cancer, including acute and chronic leukemia. Inhibitors of the PI3K/Akt/mTOR pathway have been used in leukemia treatment since 2014, and some of them have improved treatment outcomes in clinical trials. Recently, new inhibitors of PI3K/Akt/mTOR signaling have been developed and tested both in preclinical and clinical models. In this review, we outline the role of the PI3K/Akt/mTOR signaling pathway in blood malignancies' cells and gather information on the inhibitors of this pathway that might provide a novel therapeutic opportunity against leukemia.

Combination therapy of acute myeloid leukemia by dual PI3K/mTOR inhibitor BEZ235 and TLR-7/8 agonist R848 in murine model.

BACKGROUND: Due to the high relapse rate and toxicity of the common therapies in patients with acute myeloid leukemia (AML), modifications in the treatment strategies are required. The present study was conducted to determine the effects of combinational therapy with a dual PI3K/mTOR inhibitor, BEZ235, and TLR7/8 agonist, R848, on murine AML model. METHODS: BEZ235 and R848 were administered to AML leukemic mice in either a single or combination treatment. Frequency of T-CD4+, T-CD8+, MDSCs, NK, exhausted T cells and the degranulation levels was measured via flow cytometry. The cytotoxicity and proliferation levels were evaluated by MTT assay. Then, the expression of iNOS, arginase-1, PD-L1, Gal-9, PVR, IFN-γ, TNF-α, IL-4, IL-10, IL-12 and IL-17 was investigated by Real-Time PCR. Organomegaly, body weight and survival rate were also monitored. RESULTS: Following combinational therapy with BEZ235 and R848, increasing in the frequency of anti-tumor immune cells including T-CD4+ cells and M1 macroghages, and decreasing in pro-tumor immune cells including MDSCs, exhausted T-CD4+ and T-CD8+ cells and also M2 macrophages were observed. The functional defects of immune cells in term of proliferation, cytotoxicity, degranulation, and cytokines expression were improved in leukemic mice after treatment with BEZ235 and R848. Finally, organomegaly, body weight and survival analysis showed significant improvements after treatment with BEZ235 and R848. CONCLUSION: Taken together, we indicated that the combinational therapy with BEZ235 and R848 could be considered as a potential and powerful therapeutic option for AML patients. Further clinical studies are required to expand our current findings.

Discovery of novel potent PI3K/mTOR dual-target inhibitors based on scaffold hopping: Design, synthesis, and antiproliferative activity.

The PI3K/AKT/mTOR pathway is one of the most common dysregulated signaling cascade responses in human cancers, playing a crucial role in cell proliferation and angiogenesis. Therefore, the development of anticancer drugs targeting the PI3K and mTOR pathways has become a research hotspot in cancer treatment. In this study, the PI3K selective inhibitor GDC-0941 was selected as a lead compound, and 28 thiophenyl-triazine derivatives with aromatic urea structures were synthesized based on scaffold hopping, serving as a novel class of PI3K/mTOR dual inhibitors. The most promising compound Y-2 was obtained through antiproliferative activity evaluation, kinase inhibition, and toxicity assays. The results showed that Y-2 demonstrated potential inhibitory effects on both PI3K kinase and mTOR kinase, with IC50 values of 171.4 and 10.2 nM, respectively. The inhibitory effect of Y-2 on mTOR kinase was 52 times greater than that of the positive drug GDC-0941. Subsequently, the antitumor activity of Y-2 was verified through pharmacological experiments such as AO staining, cell apoptosis, scratch assays, and cell colony formation. The antitumor mechanism of Y-2 was further investigated through JC-1 experiments, real-time quantitative PCR, and Western blot analysis. Based on the above experiments, Y-2 can be identified as a potent PI3K/mTOR dual inhibitor for cancer treatment.

Efficacy and safety of abemaciclib alone and with PI3K/mTOR inhibitor LY3023414 or galunisertib versus chemotherapy in previously treated metastatic pancreatic adenocarcinoma: A randomized controlled trial.

BACKGROUND: Pancreatic ductal adenocarcinomas (PDAC) are characterized by frequent cell cycle pathways aberrations. This study evaluated safety and efficacy of abemaciclib, a cyclin-dependent kinase 4 and 6 inhibitor, as monotherapy or in combination with PI3K/mTOR dual inhibitor LY3023414 or TGFß inhibitor galunisertib versus standard of care (SOC) chemotherapy in patients with pretreated metastatic PDAC. METHODS: This Phase 2 open-label study enrolled patients with metastatic PDAC who progressed after 1-2 prior therapies. Patients were enrolled in a safety lead-in (abemaciclib plus galunisertib) followed by a 2-stage randomized design. Stage 1 randomization was planned 1:1:1:1 for abemaciclib, abemaciclib plus LY3023414, abemaciclib plus galunisertib, or SOC gemcitabine or capecitabine. Advancing to Stage 2 required a disease control rate (DCR) difference ≥0 in abemaciclib-containing arms versus SOC. Primary objectives for Stages 1 and 2 were DCR and progression-free survival (PFS), respectively. Secondary objectives included response rate, overall survival, safety, and pharmacokinetics. RESULTS: One hundred and six patients were enrolled. Abemaciclib plus galunisertib did not advance to Stage 1 for reasons unrelated to safety or efficacy. Stage 1 DCR was 15.2% with abemaciclib monotherapy, 12.1% with abemaciclib plus LY3023414, and 36.4% with SOC. Median PFS was 1.7 months (95% CI: 1.4-1.8), 1.8 months (95% CI: 1.3-1.9), and 3.3 months (95% CI: 1.1-5.7), respectively. No arms advanced to Stage 2. No new safety signals were identified. CONCLUSION: In patients with pretreated metastatic PDAC, abemaciclib-based therapy did not improve DCRs or PFS compared with SOC chemotherapy. No treatment arms advanced to Stage 2. Abemaciclib remains investigational in patients with PDAC.

XBP1 promotes NRASG12D pre-B acute lymphoblastic leukaemia through IL-7 receptor signalling and provides a therapeutic vulnerability for oncogenic RAS.

Activating point mutations of the RAS gene act as driver mutations for a subset of precursor-B cell acute lymphoblastic leukaemias (pre-B ALL) and represent an ambitious target for therapeutic approaches. The X box-binding protein 1 (XBP1), a key regulator of the unfolded protein response (UPR), is critical for pre-B ALL cell survival, and high expression of XBP1 confers poor prognosis in ALL patients. However, the mechanism of XBP1 activation has not yet been elucidated in RAS mutated pre-B ALL. Here, we demonstrate that XBP1 acts as a downstream linchpin of the IL-7 receptor signalling pathway and that pharmacological inhibition or genetic ablation of XBP1 selectively abrogates IL-7 receptor signalling via inhibition of its downstream effectors, JAK1 and STAT5. We show that XBP1 supports malignant cell growth of pre-B NRASG12D ALL cells and that genetic loss of XBP1 consequently leads to cell cycle arrest and apoptosis. Our findings reveal that active XBP1 prevents the cytotoxic effects of a dual PI3K/mTOR pathway inhibitor (BEZ235) in pre-B NRASG12D ALL cells. This implies targeting XBP1 in combination with BEZ235 as a promising new targeted strategy against the oncogenic RAS in NRASG12D -mutated pre-B ALL.

Chitosan nanoparticles encapsulated with BEZ235 prevent acute rejection in mouse heart transplantation.

Acute rejection may manifest following heart transplantation, despite the implementation of relatively well-established immunosuppression protocols. The significance of the mTOR signaling pathway in rejection is widely acknowledged. BEZ235, a second-generation mTOR inhibitor with dual inhibitory effects on PI3K and mTOR, holds promise for clinical applications. This study developed a nanodelivery system, BEZ235@NP, to facilitate the intracellular delivery of BEZ235, which enhances efficacy and reduces adverse effects by improving the poor solubility of BEZ235. In the complete MHCII-mismatched model, BEZ235@NP significantly prolonged cardiac allografts survival compared to free BEZ235, which was attributed to more effective suppression of effector T cell activation and promotion of greater expansion of Tregs. These nanoparticles demonstrated excellent biosafety and exhibited no short-term biotoxicity upon investigation. To elucidate the mechanism, primary T cells were isolated from the spleen and it was observed that BEZ235@NP treatment resulted in the arrest of these cells in the G0/G1 phase. As indicated by Western blot analysis, BEZ235@NP substantially reduced mTOR phosphorylation. This, in turn, suppressed downstream pathways and ultimately exerted an anti-proliferative and anti-activating effect on cells. Furthermore, it was observed that inhibition of the mTOR pathway stimulated T-cell autophagy. In conclusion, the strategy of intracellular delivery of BEZ235 presents promising applications for the treatment of acute rejection.