Drugging the PI3K/AKT/mTOR Pathway in ER+ Breast Cancer

Platelet-rich plasma combined with isometric quadriceps contraction regulates autophagy in chondrocytes via the PI3K/AKT/mTOR pathway to promote cartilage repair in knee osteoarthritis

Background

This study investigated the molecular mechanism by which the combination of platelet-rich plasma (PRP) and isometric contraction of the quadriceps (ICQ) intervention regulates autophagy in chondrocytes to prevent and treat knee osteoarthritis (KOA).

Methods

Thirty Sprague-Dawley rats were divided into a control group (CG, n = 6) and a model group (n = 24). After one week, the model group was randomly divided into a joint intervention group (JIG), a rapamycin group (RAG), an MHY1485 group (MYG), and a model blank group (MBG), with JIG, RAG, and MYG receiving the same combined intervention.

Results

The trend of cartilage lesions in each group was CG < RAG < JIG < MYG < MBG. Compared with MBG and MYG, JIG and RAG showed downregulation of IL-1β, IL-6, IL-18, MMP-13, and TNF-α mRNA in the cartilage (p < 0.01); mTOR protein expression: compared with JIG, RAG showed downregulation, and MYG showed upregulation. Compared with RAG, MYG showed upregulation (p < 0.01); ATG5 protein expression: compared with RAG, MYG showed downregulation (p < 0.01); Beclin1, LC3-I, and ULK1 protein expression: compared with JIG, RAG showed upregulation, and MYG showed downregulation (p < 0.01). Compared with RAG, MYG showed downregulation (p < 0.01); P62 protein expression: compared with RAG, both MBG and RAG showed upregulation, and MYG showed downregulation (p < 0.05); LC3-II/LC3-I ratio: compared with JIG and RAG, the ratio in MYG was decreased (p < 0.01).

Conclusion

The combined intervention promotes autophagy in chondrocytes by inhibiting the PI3K/AKT/mTOR pathway, downregulating inflammatory factors and MMP-13 in the cartilage, upregulating autophagy markers, inhibiting matrix degradation, and promoting cartilage repair.

Predicting breast cancer prognosis using PR and PIK3CA biomarkers: a comparative analysis of diagnostic groups

PURPOSE

To evaluate the prognostic significance of progesterone receptor (PR) expression and the PIK3CA mutation status in HR+/HER2 - breast cancer patients, with the goal of screening patients who may derive the greatest benefit from PI3K-targeted therapy.

METHODS

A retrospective analysis was conducted on 152 HR+/HER2 - breast cancer patients stratified by PR expression levels and PIK3CA mutation status. The study population was divided into groups on the basis of a median PR threshold of 50% and further subdivided by PIK3CA mutation status. To evaluate the variability of clinicopathologic features among these groups, t tests and ANOVA were employed. The influence of these variables on survival was analyzed via Cox regression. Additionally, a risk prediction model was developed using the PR expression level and PIK3CA mutation status. The prognostic utility of this model was examined via both Kaplan‒Meier (KM) survival curves and receiver operating characteristic (ROC) analyses. These methods have also been utilized to explore the associations between clinicopathologic parameters and clinical outcomes with respect to survival prediction and prognosis.

RESULTS

Significant differences in age, ER expression, and Ki67, HER2, and PIK3CA mutation status were detected between the groups (P < 0.05). Specifically, elevated PR expression was correlated with lower levels of Ki67 and low HER2 expression. The presence of a PIK3CA mutation was significantly linked to survival outcomes according to both univariate and multivariate Cox regression analyses. Moreover, ROC analysis revealed that models incorporating both PR expression and PIK3CA mutation status achieved the highest level of diagnostic precision (AUC = 0.82).

CONCLUSION

PR expression and PIK3CA mutation status are significant prognostic markers in HR+/HER2 - breast cancer patients. Assessing these biomarkers in combination can enhance prognostic stratification, potentially guiding more informed clinical decision-making.

In Silico Design of Dual Estrogen Receptor and Hsp90 Inhibitors for ER-Positive Breast Cancer Through a Mixed Ligand/Structure-Based Approach

Breast cancer remains one of the most prevalent and lethal malignancies in women, particularly the estrogen receptor-positive (ER+) subtype, which accounts for approximately 70% of cases. Traditional endocrine therapies, including aromatase inhibitors, selective estrogen receptor degraders/antagonists (SERDs), and selective estrogen receptor modulators (SERMs), have improved outcomes for metastatic ER+ breast cancer. However, resistance to these agents presents a significant challenge. This study explores a novel therapeutic strategy involving the simultaneous inhibition of the estrogen receptor (ER) and the chaperone protein Hsp90, which is crucial for the stabilization of various oncoproteins, including ER itself. We employed a hybrid, hierarchical in silico virtual screening approach to identify new dual ER/Hsp90 inhibitors, utilizing the Biotarget Predictor Tool (BPT) for efficient multitarget screening of a large compound library. Subsequent structure-based studies, including molecular docking analyses, were conducted to further evaluate the interaction of the top candidates with both ER and Hsp90. Supporting this, molecular dynamics simulations demonstrate the high stability of the multitarget inhibitor 755435 in complex with ER and Hsp90. Our findings suggest that several small molecules, particularly compound 755435, exhibit promising potential as dual inhibitors, representing a new avenue to overcome resistance in ER+ breast cancer.

Combined treatment with ruxolitinib and MK-2206 inhibits ERα activity by inhibiting MAPK signaling in BT474 breast cancer cells

Triple-positive breast cancer (TPBC) is a type of breast cancer that overexpresses estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER2). Dysregulation of ER signaling has been implicated in the pathogenesis of breast cancer. ERα activation triggers the production of second messengers, including cAMP, leading to the activation of signals such as PI3K/AKT or Ras/MAPK. Ruxolitinib is a specific inhibitor of JAK1/JAK2. MK-2206 is an allosteric inhibitor of the Akt. The limitations of the use of ruxolitinib and MK-2206 as single agents necessitate the development of combination therapies with other drugs. This study is the first to investigate the effects of combining ruxolitinib with MK-2206 on MAPK and PI3K/AKT signaling in BT474 breast cancer cells. In addition, this work aimed to increase the anticancer effects of cotreatment with MK-2206 and ruxolitinib. Ruxolitinib, MK-2206, and their combination reduced cell viability in a dose- and time-dependent manner, as determined by MTT assays after 48 h of treatment. Colony formation and wound healing assays demonstrated that MK-2206 exhibited a synergistic anti-proliferative effect. The effects of ruxolitinib, MK-2206, and their combination on PI3K/AKT and MAPK signaling were assessed via western blotting. Ruxolitinib and MK-2206 combined treatment inhibit cell death in BT474 cells by downregulating ERα, Src-1, ERK1/2, SAPK/JNK, and c-Jun. Our results revealed the relationships among the ERα, PI3K/AKT, and MAPK signaling pathways in ER+ breast cancer cells. Understanding the interactions among ERα, PI3K-AKT-mTOR, and MAPK could lead to novel combination therapies.

Role and Interplay of Different Signaling Pathways Involved in Sciatic Nerve Regeneration

Regeneration of the sciatic nerve is a sophisticated process that involves the interplay of several signaling pathways that orchestrate the cellular responses critical to regeneration. Among the key pathways are the mitogen-activated protein kinase (MAPK), phosphatidylinositol 3-kinase (PI3K)/AKT, cyclic adenosine monophosphate (cAMP), and Janus kinase/signal transducers and transcription activators (JAK/STAT) pathways. In particular, the cAMP pathway modulates neuronal survival and axonal regrowth. It influences various cellular behaviors and gene expression that are essential for nerve regeneration. MAPK is indispensable for Schwann cell differentiation and myelination, whereas PI3K/AKT is integral to the transcription, translation, and cell survival processes that are vital for nerve regeneration. Furthermore, GTP-binding proteins, including those of the Ras homolog gene family (Rho), regulate neural cell adhesion, migration, and survival. Notch signaling also appears to be effective in the early stages of nerve regeneration and in preventing skeletal muscle fibrosis after injury. Understanding the intricate mechanisms and interactions of these pathways is vital for the development of effective therapeutic strategies for sciatic nerve injuries. This review underscores the need for further research to fill existing knowledge gaps and improve therapeutic outcomes.

Enhancing targeted therapy by combining PI3K and AKT inhibitors with or without cisplatin or vincristine in medulloblastoma cell lines in vitro

AIM

Despite current intensive therapy, survival rates of medulloblastoma (MB) greatly vary according to molecular subgroup, so new therapies are needed. Recently, we showed that combining phosphoinositide 3-kinase (PI3K), fibroblast growth factor receptor and cyclin-dependent-kinase-4/6 inhibitors (BYL719, JNJ-42756493 and PD-0332991, respectively) or poly (ADP-ribose) polymerase (PARP) and WEE-1 inhibitors (BMN673 and MK1775 respectively) had synergistic effects on MB. Here, in continuation, we investigated the effects of single and combined administrations of PI3K and AKT inhibitors, with/without cisplatin or vincristine on adherent or suspension cultures of different MB subgroups as well as in a spheroid culture of one MB line.

MATERIAL AND METHODS

MB cell lines DAOY, UW228-3, D425, Med8A, and D283 were treated with single and combined administrations of BYL719, AZD5363, cisplatin or vincristine and followed for viability, cell confluence, cytotoxicity, and cell migration. DAOY was also tested as a spheroid culture.

KEY FINDINGS

Single BYL719, AZD5363, cisplatin, or vincristine administrations gave dose-dependent responses with regard to inhibition of viability and cell confluence. Combining AZD5363 with BYL719, cisplatin or vincristine resulted in synergistic effects with regard to inhibition of viability in all cell lines, and confluence and migration in all tested cell lines. The administration of single and combined treatments to DAOY spheroids produced largely similar effects.

SIGNIFICANCE

This study provides pre-clinical evidence that AKT inhibitors combined with PI3K inhibitors, cisplatin, or vincristine exhibit additive/synergistic anti-MB activity, and lower doses could be used. The latter also applied to one MB line grown as spheroids, further supporting their future potential use.

PLK1 Inhibitor Onvansertib Enhances the Efficacy of Alpelisib in PIK3CA-Mutated HR-Positive Breast Cancer Resistant to Palbociclib and Endocrine Therapy: Preclinical Insights

BACKGROUND

Endocrine therapy (ET) combined with cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) is the preferred first-line treatment for hormone receptor-positive (HR+)/HER2- metastatic breast cancer. Although this is beneficial, acquired resistance leads to disease progression, and patients harboring PIK3CA mutations are treated with targeted therapies such as the PI3Kα inhibitor, alpelisib, alongside ET. Drug-associated resistance mechanisms limit the efficacy of alpelisib, highlighting the need for better combination therapies. This study aimed to evaluate the efficacy of combining alpelisib with a highly specific PLK1 inhibitor, onvansertib, in PIK3CA-mutant HR+ breast cancer preclinical models.

METHODS

We assessed the effect of the alpelisib and onvansertib combination on cell viability, PI3K signaling pathway, cell cycle phase distribution and apoptosis in PI3K-activated HR+ breast cancer cell lines. The antitumor activity of the combination was evaluated in three PIK3CA-mutant HR+ breast cancer patient-derived xenograft (PDX) models, resistant to ET and CDK4/6 inhibitor palbociclib. Pharmacodynamics studies were performed using immunohistochemistry and Simple Western analyses in tumor tissues.

RESULTS

The combination synergistically inhibited cell viability, suppressed PI3K signaling, induced G2/M arrest and apoptosis in PI3K-activated cell lines. In the three PDX models, the combination demonstrated superior anti-tumor activity compared to the single agents. Pharmacodynamic studies confirmed the inhibition of both PLK1 and PI3K activity and pronounced apoptosis in the combination-treated tumors.

CONCLUSIONS

Our findings support that targeting PLK1 and PI3Kα with onvansertib and alpelisib, respectively, may be a promising strategy for patients with PIK3CA-mutant HR+ breast cancer failing ET + CDK4/6i therapies and warrant clinical evaluation.

Da-Chai-Hu-Tang Formula inhibits the progression and metastasis in HepG2 cells through modulation of the PI3K/AKT/STAT3-induced cell cycle arrest and apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Da-Chai-Hu-Tang (DCHT), a Chinese traditional herbal compound, has been utilized for the treatment of Hepatic diseases in China for over 1800 years. The DCHT formula contains eight herbals: Bupleurum chinense DC. (chaihu), Scutellaria baicalensis Georgi (huangqin), Paeonia lactiflora Pall. (baishao), Pinellia ternata (Thunb.) Makino (banxia), Rheum officinale Baill. (dahuang), Citrus × aurantium L. (zhishi), Zingiber officinale Roscoe (shengjiang), Ziziphus jujuba Mill. (dazao). Clinical studies have demonstrated the effectiveness of DCHT in hepatocellular carcinoma (HCC) and its ability to enhance the immunity of patients with hepatocellular carcinoma. A total of 20 Chinese articles have been published on the use of DCHT in treating HCC.

AIM OF THE STUDY

The study aimed to validate the effect of DCHT in HCC cells and to identify related targets (TP53, AKT1, BCL2, STAT3) in treating HCC by DCHT in vitro experiments.

MATERIALS AND METHODS

Cell proliferation and migration were investigated in vitro. Flow cytometry analysis was used to evaluate the cell cycle and apoptosis. Apoptotic bodies in HepG2 cells were observed using a confocal microscope. Biochemical detection was employed to analyze LDH release, MDA levels, and SOD levels. Bioinformatics analysis was used to predict core targets between DCHT and HCC, as well as potential signaling pathways. The protein levels of metastasis-associated, apoptosis, and PI3K, AKT, p-AKT, and STAT3 were further determined through Western blotting.

RESULTS

Following treatment with DCHT, the inhibition of viability, migration, and G2/M arrest was observed in HepG2 cells. Flow cytometry analysis and Morphological apoptosis studies provided evidence that DCHT could induce apoptosis in HepG2 cells. Biochemical detection revealed that DCHT could increase LDH release and the level of MDA, and inhibit the viability of the SOD. Bioinformatics analysis identified key targets such as TP53, AKT1, BCL2, STAT3. The PI3K/AKT/STAT3 signaling pathway emerged as a critical pathway in the KEGG enrichment analysis. Western blotting results indicated that DCHT could enhance the expression of E-cadherin, p53, and Bax, while reducing the content of N-cadherin, Bcl-2, PI3K, p-AKT, AKT1, and STAT3.

CONCLUSIONS

The results proved that DCHT could inhibit the progression and metastasis of HCC by regulating the expression of E-cadherin, N-cadherin, p53, Bax, Bcl-2, PI3K, p-AKT, AKT, and STAT3 through the PI3K/AKT/STAT3 signaling pathway.

Analysis of PIK3CA mutations in the primary and recurrent tumors of hormone receptor positive/human epidermal growth factor receptor 2 negative breast cancer

OBJECTIVE

Our aim was to compare the PIK3CA mutation status in matched primary and recurrent tumors of hormone receptor positive/human epidermal growth factor receptor 2 negative (HR+/HER2-) breast cancer (BC) to gain insight into the optimization of patient selection and detection time for PIK3CA-targeted therapy.

METHODS

The data were from 3035 patients with BC diagnosed at the Breast Disease Center, Peking University First Hospital, between January 2008 and December 2017. Matched primary and recurrent samples were profiled using amplification-refractory mutation system-polymerase chain reaction covering 11 mutational hotspots in PIK3CA.

RESULTS

PIK3CA mutations were detected in 54.3% primary tumors and 48.6% corresponding recurrences. PIK3CA mutation was detected in 37.5% cases in the locoregional recurrent group and 40.0% of distant metastasis, without a statistical difference. Besides, PIK3CA mutations were concordant in 88.6% of the matched pairs. For patients treated with neoadjuvant chemotherapy, 100% concordance was observed. However, PIK3CA mutation was neither correlated with clinicopathological features nor associated with clinical outcomes.

CONCLUSIONS

Mutations in PIK3CA in HR+/HER2- BC generally progressed to recurrent tumors. The high concordance rate of PIK3CA mutation status between primary tumors and corresponding recurrences suggests that the detection of primary tumors could be a substitute approach when recurrent samples are not easily obtainable.

Application and research progress of cordycepin in the treatment of tumours (Review)

Cordycepin is a nucleoside molecule found in Cordyceps sinensis and can be obtained through chemical synthesis and biotransformation. Cordycepin has been extensively studied and has been shown to have antitumour activity. This activity includes effects on the autophagy process and inhibition of the MAPK/ERK and Hedgehog pathways. Ultimately, the inhibitory effect of cordycepin on tumour cells is due to the interplay of these effects. Cordycepin was shown to enhance the therapeutic effects of radiotherapy. There is increasing evidence indicating that cordycepin plays an anticancer role in the treatment of various cancers. The present review aims to provide a clear understanding of the antitumour mechanisms of cordycepin and discuss its present application in the treatment of tumours. This information can be an important theoretical basis and provide clinical guidance for the further development of cordycepin as an antitumour drug.

FOXK2 amplification promotes breast cancer development and chemoresistance

Oncogene activation through DNA amplification or overexpression is a crucial driver of cancer initiation and progression. The FOXK2 gene, located on chromosome 17q25, encodes a transcription factor with a forkhead DNA-binding domain. Analysis of genomic datasets reveals that FOXK2 is frequently amplified and overexpressed in breast cancer, correlating with poor patient survival. Knockdown of FOXK2 significantly inhibited breast cancer cell proliferation, migration, anchorage-independent growth, and delayed tumor growth in a xenograft mouse model. Additionally, inhibiting FOXK2 sensitized breast cancer cells to chemotherapy. Co-overexpression of FOXK2 and mutant PI3KCA transformed non-tumorigenic MCF-10A cells, suggesting a role for FOXK2 in PI3KCA-driven tumorigenesis. CCNE2, PDK1, and ESR1 were identified as transcriptional targets of FOXK2 in MCF-7 cells. Small-molecule inhibitors of CCNE2/CDK2 (dinaciclib) and PDK1 (dichloroacetate) exhibited synergistic anti-tumor effects with PI3KCA inhibitor (alpelisib) in vitro. Inhibition of FOXK2 by dinaciclib synergistically enhanced the anti-tumor effects of alpelisib in a xenograft mouse model. Collectively, these findings highlight the oncogenic function of FOXK2 and suggest that FOXK2 and its downstream genes represent potential therapeutic targets in breast cancer.

Paeonol alleviates ox-LDL-induced endothelial cell injury by targeting the heme oxygenase-1/phosphoinositide 3-kinase/protein kinase B pathway

Atherosclerosis is a leading cause of vascular disease worldwide. Paeonol has been reported to have therapeutical potential in atherosclerosis. The aim of this study is to explore the effect of paeonol on oxidized low-density lipoprotein (ox-LDL)-induced endothelial cells injury and the underlying mechanism. Human umbilical vein endothelial cells (HUVECs) were treated with ox-LDL (100 μg/ml) to mimic atherosclerosis in vitro. The cell viability, proliferation, and apoptosis were assessed by cell counting kit-8 (CCK8), 5-ethynyl-2'-deoxyuridine (EdU), and flow cytometry, respectively. The angiogenesis was detected by tube formation assay. The levels of inflammatory factor were measured by enzyme-linked immunosorbent assay (ELISA). In addition, the levels of Fe2+, reactive oxygen species (ROS), and glutathione (GSH) were detected to assess ferroptosis. The western blot was used to detect the protein expression. Ox-LDL inhibited cell viability, proliferation, and angiogenesis, but induced apoptosis and inflammation in HUVECs, and paeonol (75 μM) relieves ox-LDL-induced HUVEC injury. Also, paeonol inhibited ox-LDL-induced ferroptosis of HUVECs. Interestingly, heme oxygenase-1 (HMOX1) knockdown alleviated ox-LDL-induced HUVECs injury and ferroptosis. Paeonol affected ox-LDL-induced HUVECs via regulating HMOX1. In addition, paeonol regulated PI3K/AKT pathway via HMOX1, and the inhibitor of phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) pathway reversed the effects of HMOX1 knockdown on ox-LDL-induced HUVECs. Paeonol alleviated ox-LDL-induced HUVEC injury by regulating the PI3K/AKT pathway via targeting HMOX1.

Asiatic acid inhibits cervical cancer cell proliferation and migration via PI3K/AKT/mTOR signaling pathway

Cervical cancer (CC) is a malignant tumor of the female reproductive system that typically occurs in cervical cells and has high incidence and mortality rates, strong metastatic ability, and poor prognosis. Asiatic acid (AA) exhibits anti-inflammatory, anti-depressant, and anti-tumor effects. However, the molecular targets and mechanisms underlying AA-mediated inhibition of CC metastasis remain unclear. AA affects the proliferation, metastasis, and epithelial-mesenchymal transition (EMT) process of CC cell lines. MTT experiments verified that AA inhibited the proliferation ability of CC cells, and the effect of AA on the lateral and longitudinal migration ability of CC was evaluated through wound healing and Transwell assays. Western blotting was used to explore whether AA inhibits EMT process in HeLa and C33a cells. Currently, targeting the PI3K/AKT/mTOR pathway as a strategy for cancer treatment remains an evolving field. However, the molecular mechanism by which AA inhibits CC via the PI3K/AKT/mTOR pathway remains unclear and requires further investigation.

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

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

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

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

Gedatolisib in combination with palbociclib and endocrine therapy in women with hormone receptor-positive, HER2-negative advanced breast cancer: results from the dose expansion groups of an open-label, phase 1b study

BACKGROUND

The PI3K-mTOR pathway is frequently dysregulated in breast cancer. Combining an inhibitor targeting all class I PI3K isoforms and mTOR complex 1 (mTORC1)-mTOR complex 2 (mTORC2) with endocrine therapy and a CDK4/6 inhibitor might provide more effective tumour control than standard-of-care therapy. To evaluate this hypothesis, gedatolisib, a pan-PI3K-mTOR inhibitor, was assessed in a phase 1b trial combined with palbociclib and endocrine therapy in patients with hormone receptor-positive, HER2-negative, advanced breast cancer. Results from the dose expansion portion of this trial are reported herein.

METHODS

This multicentre, open-label, phase 1b study recruited female patients aged at least 18 years from 17 sites across the USA with hormone-receptor-positive, HER2-negative, advanced breast cancer and an Eastern Cooperative Oncology Group performance status of 0-1. Four patient groups were studied in the dose expansion portion of the study: treatment-naive in the advanced setting (first line; group A), progression on 1-2 lines of endocrine therapy but CDK4/6 inhibitor-naive (group B); and one or more previous lines (second-line and higher) of therapy, including a CDK4/6 inhibitor (groups C and D). Gedatolisib 180 mg was administered intravenously weekly in 28-day treatment cycles for groups A-C, and on days 1, 8, and 15 for group D. Letrozole (group A), fulvestrant (groups B-D), and palbociclib (all groups) were administered at standard doses and schedules. The primary endpoint was investigator-assessed objective response rate per RECIST version 1.1 in the evaluable analysis set. This trial is completed and registered with ClinicalTrials.gov, NCT02684032.

FINDINGS

Between Dec 19, 2017, and June 19, 2019, 103 female participants were enrolled in the dose expansion groups A (n=31), B (n=13), C (n=32), and D (n=27). Median follow-up was 16·6 months (IQR 5·7-48·4) for group A, 11·0 months (7·6-16·9) for group B, 3·6 months (1·8-7·5) for group C, and 9·4 months (5·3-16·7) for group D for the primary endpoint. Gedatolisib, palbociclib, and endocrine therapy induced an objective response in 23 (85·2%; 90% CI 69·2-94·8) of 27 evaluable first-line participants (group A). In the second-line and higher setting, an objective response was observed in eight (61·5%; 90% CI 35·5-83·4) of 13 evaluable group B participants, seven (25·0%; 12·4-41·9) of 28 evaluable group C participants, and 15 (55·6%; 38·2-72·0) of 27 evaluable group D participants; this included participants with both wild-type and mutated PIK3CA tumours. The most common grade 3-4 treatment-related adverse events were neutropenia (65 [63%] of 103), stomatitis (28 [27%]), and rash (21 [20%]). Grade 3-4 hyperglycaemia was reported in six (6%) participants. 23 (22%) of 103 participants had a treatment-related serious adverse event, and there were no treatment-related deaths. Nine (9%) participants discontinued treatment because of a treatment-emergent adverse event.

INTERPRETATION

Gedatolisib plus palbociclib and endocrine therapy showed a promising objective response rate compared with the published results for standard-of-care therapies and had an acceptable safety profile.

FUNDING

Pfizer and Celcuity.

Targeting triple negative breast cancer stem cells using nanocarriers

Breast cancer is a complex and heterogeneous disease, encompassing various subtypes characterized by distinct molecular features, clinical behaviors, and treatment responses. Categorization of subtypes is based on the presence or absence of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2), leading to subtypes such as luminal A, luminal B, HER2-positive, and triple-negative breast cancer (TNBC). TNBC, comprising around 20% of all breast cancers, lacks expression of ER, PR, and HER2 receptors, rendering it unresponsive to targeted therapies and presenting significant challenges in treatment. TNBC is associated with aggressive behavior, high rates of recurrence, and resistance to chemotherapy. Tumor initiation, progression, and treatment resistance in TNBC are attributed to breast cancer stem cells (BCSCs), which possess self-renewal, differentiation, and tumorigenic potential. Surface markers, self-renewal pathways (Notch, Wnt, Hedgehog signaling), apoptotic protein (Bcl-2), angiogenesis inhibition (VEGF inhibitors), and immune modulation (cytokines, immune checkpoint inhibitors) are among the key targets discussed in this review. However, targeting the BCSC subpopulation in TNBC presents challenges, including off-target effects, low solubility, and bioavailability of anti-BCSC agents. Nanoparticle-based therapies offer a promising approach to target various molecular pathways and cellular processes implicated in survival of BSCS in TNBC. In this review, we explore various nanocarrier-based approaches for targeting BCSCs in TNBC, aiming to overcome these challenges and improve treatment outcomes for TNBC patients. These nanoparticle-based therapeutic strategies hold promise for addressing the therapeutic gap in TNBC treatment by delivering targeted therapies to BCSCs while minimizing systemic toxicity and enhancing treatment efficacy.

Targeting PI3K/AKT/mTOR and MAPK Signaling Pathways in Gastric Cancer

Gastric cancer (GC) is the fourth leading cause of death worldwide, with more than 1 million cases diagnosed every year. Helicobacter pylori represents the main risk factor, being responsible for 78% of the cases. Increased amounts of salt, pickled food, red meat, alcohol, smoked food, and refined sugars negatively affect the stomach wall, contributing to GC development. Several gene mutations, including PIK3CA, TP53, ARID1A, CDH1, Ras, Raf, and ERBB3 are encountered in GC pathogenesis, leading to phosphatidylinositol 3-kinase (PI3K) protein kinase B (AKT)/mammalian target of rapamycin (mTOR)-PI3K/AKT/mTOR-and mitogen-activated protein kinase (MAPK) signaling pathway activation and promoting tumoral activity. Helicobacter pylori, growth factors, cytokines, hormones, and oxidative stress also activate both pathways, enhancing GC development. In clinical trials, promising results have come from monoclonal antibodies such as trastuzumab and ramucirumab. Dual inhibitors targeting the PI3K/AKT/mTOR and MAPK signaling pathways were used in vitro studies, also with promising results. The main aim of this review is to present GC incidence and risk factors and the dysregulations of the two protein kinase complexes together with their specific inhibitors.

Properties of FDA-approved small molecule protein kinase inhibitors: A 2024 update

Owing to the dysregulation of protein kinase activity in many diseases including cancer, this enzyme family has become one of the most important drug targets in the 21st century. There are 80 FDA-approved therapeutic agents that target about two dozen different protein kinases and seven of these drugs were approved in 2023. Of the approved drugs, thirteen target protein-serine/threonine protein kinases, four are directed against dual specificity protein kinases (MEK1/2), twenty block nonreceptor protein-tyrosine kinases, and 43 inhibit receptor protein-tyrosine kinases. The data indicate that 69 of these drugs are prescribed for the treatment of neoplasms. Six drugs (abrocitinib, baricitinib, deucravacitinib, ritlecitinib, tofacitinib, upadacitinib) are used for the treatment of inflammatory diseases (atopic dermatitis, rheumatoid arthritis, psoriasis, alopecia areata, and ulcerative colitis). Of the 80 approved drugs, nearly two dozen are used in the treatment of multiple diseases. The following seven drugs received FDA approval in 2023: capivasertib (HER2-positive breast cancer), fruquintinib (metastatic colorectal cancer), momelotinib (myelofibrosis), pirtobrutinib (mantle cell lymphoma, chronic lymphocytic leukemia, small lymphocytic lymphoma), quizartinib (Flt3-mutant acute myelogenous leukemia), repotrectinib (ROS1-positive lung cancer), and ritlecitinib (alopecia areata). All of the FDA-approved drugs are orally effective with the exception of netarsudil, temsirolimus, and trilaciclib. This review summarizes the physicochemical properties of all 80 FDA-approved small molecule protein kinase inhibitors including the molecular weight, number of hydrogen bond donors/acceptors, polar surface area, potency, solubility, lipophilic efficiency, and ligand efficiency.

PIK3CA testing in hormone receptor-positive/HER2-negative metastatic breast cancer: real-world data from Italian molecular pathology laboratories

Introduction: PIK3CA gene mutations occur in approximately 40% of hormone receptor-positive/HER2-negative (HR+/HER2-) metastatic breast cancers (MBCs), electing them to targeted therapy. Testing PIK3CA status is complex due to selection of biological specimen and testing method. Materials & methods: This work investigates real-life experience on PIK3CA testing in HR+/HER2- MBC. Clinical, technical and molecular data on PIK3CA testing were collected from two referral laboratories. Additionally, the results of a nationwide PIK3CA survey involving 116 institutions were assessed. Results: Overall, n = 35 MBCs were PIK3CA-mutated, with mutations mostly occurring in exons 9 (n = 19; 51.4%) and 20 (n = 15; 40.5%). The nationwide survey revealed significant variability across laboratories in terms of sampling methodology, technical assessment and clinical report signing healthcare figures for PIK3CA molecular testing in diagnostic routine practice. Conclusion: This study provides insights into the real-world routine of PIK3CA testing in HR+/HER2- MBC and highlights the need for standardization and networking in predictive pathology.

Therapeutic evolution in HR+/HER2- breast cancer: from targeted therapy to endocrine therapy

Breast cancer, a complex and varied disease, has four distinct subtypes based on estrogen receptor and human epidermal growth factor receptor 2 (HER2) levels, among which a significant subtype known as HR+/HER2-breast cancer that has spurred numerous research. The prevalence of breast cancer and breast cancer-related death are the most serious threats to women's health worldwide. Current progress in treatment strategies for HR+/HER2-breast cancer encompasses targeted therapy, endocrine therapy, genomic immunotherapy, and supplementing traditional methods like surgical resection and radiotherapy. This review article summarizes the current epidemiology of HR+/HER2-breast cancer, introduces the classification of HR+/HER2-breast cancer and the commonly used treatment methods. The mechanisms of action of various drugs, including targeted therapy drugs and endocrine hormone therapy drugs, and their potential synergistic effects are deeply discussed. In addition, clinical trials of these drugs that have been completed or are still in progress are included.

Predictive, preventive, and personalized medicine in breast cancer: targeting the PI3K pathway

Breast cancer (BC) is a multifaceted disease characterized by distinct molecular subtypes and varying responses to treatment. In BC, the phosphatidylinositol 3-kinase (PI3K) pathway has emerged as a crucial contributor to the development, advancement, and resistance to treatment. This review article explores the implications of the PI3K pathway in predictive, preventive, and personalized medicine for BC. It emphasizes the identification of predictive biomarkers, such as PIK3CA mutations, and the utility of molecular profiling in guiding treatment decisions. The review also discusses the potential of targeting the PI3K pathway for preventive strategies and the customization of therapy based on tumor stage, molecular subtypes, and genetic alterations. Overcoming resistance to PI3K inhibitors and exploring combination therapies are addressed as important considerations. While this field holds promise in improving patient outcomes, further research and clinical trials are needed to validate these approaches and translate them into clinical practice.

Novel Pyrazino[2,3-b] Pyrazines as mTOR Kinase Inhibitors for Treating Cancer and other Diseases

This paper describes the synthesis of some heteroaryl compounds and compositions comprising an effective amount of one or more such compounds and methods for treating or preventing cancer, inflammatory conditions, immunological conditions, metabolic conditions and conditions treatable or preventable by inhibition of a kinase pathway, comprising administering an adequate amount of a heteroaryl compound to a patient in need thereof. These compounds are mTOR/PI3K/Akt pathway inhibitors.

Elucidation of the Role of the Epigenetic Regulatory Mechanisms of PI3K/Akt/mTOR Signaling Pathway in Human Malignancies

The PI3K/Akt/mTOR pathway modulates cell growth, proliferation, metabolism, and movement. Moreover, significant studies have shown that the genes involved in this pathway are frequently activated in human cancer. Observational and computational modeling of the PI3K/AKt/ mTOR pathway inhibitors has been explored in clinical trials. It has been observed that the effectiveness and safety evidence from clinical studies and various inhibitors of this route have been given FDA approval. In this review article, we focused on the processes behind the overactivation of PI3K/Akt/mTOR signaling in cancer and provided an overview of PI3K/Akt/mTOR inhibitors as either individual drugs or a combination of different doses of drugs for different types of cancer. Furthermore, the review discusses the biological function and activation of the PI3K/AKt/mTOR signaling and their role in the development of cancers. Additionally, we discussed the potential challenges and corresponding prediction biomarkers of response and resistance for PI3K/Akt/m- TOR inhibitor development. The article focuses on the most current breakthroughs in using the PI3K/Akt/mTOR pathway to target certain molecules.

Exploring the role of PI3K/AKT/mTOR inhibitors in hormone-related cancers: A focus on breast and prostate cancer

Breast cancer (BC) and prostate cancer (PC) are at the top of the list when it comes to the most common types of cancers worldwide. The phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway is important, in that it strongly influences the development and progression of these tumors. Previous studies have emphasized the key role of inhibitors of the PIK3/AKT/mTOR signaling pathway in the treatment of BC and PC, and it remains to be a crucial method of treatment. In this review, the inhibitors of these signaling pathways are compared, as well as their effectiveness in therapy and potential as therapeutic agents. The use of these inhibitors as polytherapy is evaluated, especially with the use of hormonal therapy, which has shown promising results.

Function of Long Noncoding RNAs in Glioma Progression and Treatment Based on the Wnt/β-Catenin and PI3K/AKT Signaling Pathways

Gliomas are a deadly primary malignant tumor of the central nervous system, with glioblastoma (GBM) representing the most aggressive type. The clinical prognosis of GBM patients remains bleak despite the availability of multiple options for therapy, which has needed us to explore new therapeutic methods to face the rapid progression, short survival, and therapy resistance of glioblastomas. As the Human Genome Project advances, long noncoding RNAs (lncRNAs) have attracted the attention of researchers and clinicians in cancer research. Numerous studies have found aberrant expression of signaling pathways in glioma cells. For example, lncRNAs not only play an integral role in the drug resistance process by regulating the Wnt/β-catenin or PI3K/Akt signaling but are also involved in a variety of malignant biological behaviors such as glioma proliferation, migration, invasion, and tumor apoptosis. Therefore, the present review systematically assesses the existing research evidence on the malignant progression and drug resistance of glioma, focusing on the critical role and potential function of lncRNAs in the Wnt/β-catenin and PI3K/Akt classical pathways to promote and encourage further research in this field.

Unveiling the connection: Long-chain non-coding RNAs and critical signaling pathways in breast cancer

Breast cancer is a complex and diverse condition that disrupts multiple signaling pathways essential for cell proliferation, survival, and differentiation. Recently, the significant involvement of long-chain non-coding RNAs (lncRNAs) in controlling key signaling pathways associated with breast cancer development has been discovered. This review aims to explore the interaction between lncRNAs and various pathways, including the AKT/PI3K/mTOR, Wnt/β-catenin, Notch, DNA damage response, TGF-β, Hedgehog, and NF-κB signaling pathways, to gain a comprehensive understanding of their roles in breast cancer. The AKT/PI3K/mTOR pathway regulates cell growth, survival, and metabolic function. Recent data suggests that specific lncRNAs can influence the functioning of this pathway, acting as either oncogenes or tumor suppressors. Dysregulation of this pathway is commonly observed in breast cancer cases. Moreover, breast cancer development has been associated with other pathways such as Wnt/β-catenin, Notch, TGF-β, Hedgehog, and NF-κB. Emerging studies have identified lncRNAs that modulate breast cancer's growth, progression, and metastasis by interacting with these pathways. To advance the development of innovative diagnostic tools and targeted treatment options, it is crucial to comprehend the intricate relationship between lncRNAs and vital signaling pathways in breast cancer. By fully harnessing the therapeutic potential of lncRNAs, there is a possibility of developing more effective and personalized therapy choices for breast cancer patients. Further investigation is necessary to comprehensively understand the role of lncRNAs within breast cancer signaling pathways and fully exploit their therapeutic potential.

Recent advances in targeted strategies for triple-negative breast cancer

Triple-negative breast cancer (TNBC), a highly aggressive subtype of breast cancer, negatively expresses estrogen receptor, progesterone receptor, and the human epidermal growth factor receptor 2 (HER2). Although chemotherapy is the main form of treatment for patients with TNBC, the effectiveness of chemotherapy for TNBC is still limited. The search for more effective therapies is urgent. Multiple targeted therapeutic strategies have emerged according to the specific molecules and signaling pathways expressed in TNBC. These include PI3K/AKT/mTOR inhibitors, epidermal growth factor receptor inhibitors, Notch inhibitors, poly ADP-ribose polymerase inhibitors, and antibody-drug conjugates. Moreover, immune checkpoint inhibitors, for example, pembrolizumab, atezolizumab, and durvalumab, are widely explored in the clinic. We summarize recent advances in targeted therapy and immunotherapy in TNBC, with the aim of serving as a reference for the development of individualized treatment of patients with TNBC in the future.

PI3K/AKT/mTOR signaling transduction pathway and targeted therapies in cancer

The PI3K/AKT/mTOR (PAM) signaling pathway is a highly conserved signal transduction network in eukaryotic cells that promotes cell survival, cell growth, and cell cycle progression. Growth factor signalling to transcription factors in the PAM axis is highly regulated by multiple cross-interactions with several other signaling pathways, and dysregulation of signal transduction can predispose to cancer development. The PAM axis is the most frequently activated signaling pathway in human cancer and is often implicated in resistance to anticancer therapies. Dysfunction of components of this pathway such as hyperactivity of PI3K, loss of function of PTEN, and gain-of-function of AKT, are notorious drivers of treatment resistance and disease progression in cancer. In this review we highlight the major dysregulations in the PAM signaling pathway in cancer, and discuss the results of PI3K, AKT and mTOR inhibitors as monotherapy and in co-administation with other antineoplastic agents in clinical trials as a strategy for overcoming treatment resistance. Finally, the major mechanisms of resistance to PAM signaling targeted therapies, including PAM signaling in immunology and immunotherapies are also discussed.

Update Breast Cancer 2023 Part 2 - Advanced-Stage Breast Cancer

In recent years, a number of new therapies have led to advances in the treatment of patients with advanced breast carcinoma. These substances are mainly CDK4/6 inhibitors and other substances that can overcome endocrine resistance, oral selective estrogen receptor degraders, antibody drug conjugates (ADCs), and PARP inhibitors. This review summarizes and evaluates the latest study results that have been published in recent months. This includes the overall survival data of the Destiny-Breast03 study, the first analysis of the CAPItello-291 study, the comparison of CDK4/6 inhibitor treatment with chemotherapy in the first line of therapy (RIGHT Choice study), the first analysis of the Destiny-Breast02 study in the treatment setting after T-DM1 treatment, and the first analysis of the Serena-2 study. Most of these studies have the potential to significantly change the therapeutic landscape for patients with advanced breast carcinoma and show that the continued rapid development of new therapies is always producing new results.

FOXK2 amplification and overexpression promotes breast cancer development and chemoresistance

Activation of oncogenes through DNA amplification/overexpression plays an important role in cancer initiation and progression. Chromosome 17 has many cancer-associated genetic anomalies. This cytogenetic anomaly is strongly associated with poor prognosis of breast cancer. FOXK2 gene is located on 17q25 and encodes a transcriptional factor with a forkhead DNA binding domain. By integrative analysis of public genomic datasets of breast cancers, we found that FOXK2 is frequently amplified and overexpressed in breast cancers. FOXK2 overexpression in breast cancer patients is associated with poor overall survival. FOXK2 knockdown significantly inhibits cell proliferation, invasion and metastasis, and anchorage-independent growth, as well as causes G0/G1 cell cycle arrest in breast cancer cells. Moreover, inhibition of FOXK2 expression sensitizes breast cancer cells to frontline anti-tumor chemotherapies. More importantly, co-overexpression of FOXK2 and PI3KCA with oncogenic mutations (E545K or H1047R) induces cellular transformation in non-tumorigenic MCF10A cells, suggesting that FOXK2 is an oncogene in breast cancer and is involved in PI3KCA-driven tumorigenesis. Our study identified CCNE2, PDK1, and Estrogen receptor alpha (ESR1) as direct transcriptional targets of FOXK2 in MCF-7 cells. Blocking CCNE2- and PDK1-mediated signaling by using small molecule inhibitors has synergistic anti-tumor effects in breast cancer cells. Furthermore, FOXK2 inhibition by gene knockdown or inhibitors for its transcriptional targets (CCNE2 and PDK1) in combination with PI3KCA inhibitor, Alpelisib, showed synergistic anti-tumor effects on breast cancer cells with PI3KCA oncogenic mutations. In summary, we provide compelling evidence that FOXK2 plays an oncogenic role in breast tumorigenesis and targeting FOXK2-mediated pathways may be a potential therapeutic strategy in breast cancer.