Phosphatidylinositol 3-Kinase, Growth Disorders, and Cancer

Combinatorial screen of targeted agents with the PI3K inhibitors inavolisib, alpelisib, duvelisib, and copanlisib in multi-cell type tumor spheroids

Dysregulation of the phosphatidylinositol 3-kinase (PI3K) pathway is a key contributor to cancer, making PI3K inhibitors a promising approach for targeted therapy. The selectivity of available inhibitors varies across different PI3K isoforms. Alpelisib and inavolisib are selective for the α-isoform, while duvelisib targets the δ- and γ-isoforms, and copanlisib is a pan-PI3K inhibitor, active against all isoforms. This study investigated the activity of these four PI3K inhibitors in combination with other targeted agents using multi-cell type tumor spheroids composed of 60% malignant cells, 25% endothelial cells, and 15% mesenchymal stem cells. Twenty-nine tumor spheroid models were evaluated, including twenty-six patient-derived cancer cell lines from the NCI Patient-Derived Models Repository and three established cell lines from the NCI-60 human tumor cell line panel. Additive and/or synergistic effects were observed with alpelisib or inavolisib or copanlisib in combination with a RAS/MEK/ERK pathway inhibitor, either selumetinib (MEK), ravoxertinib (ERK 1/2), or tovorafenib (DAY101, RAF). Combinations of each of these three PI3K inhibitors with the KRAS mutation specific inhibitors MTRX1133 (KRAS G12D) or sotorasib (KRAS G12C) had selective activity in cell lines harboring the corresponding target. Lastly, combination effects were observed from vertical inhibition of the PI3K/AKT/mTOR pathway with a PI3K inhibitor in combination with either the mTORC1/2 inhibitor sapanisertib or an AKT inhibitor, ipatasertib or afuresertib.

Class I PI3Ks activate stretch-induced autophagy in trabecular meshwork cells

Elevated intraocular pressure (IOP) is the primary risk factor for glaucoma, a leading cause of irreversible blindness worldwide. IOP homeostasis is maintained through a balance between aqueous humor production and its drainage through the trabecular meshwork (TM)/Schlemm's Canal (SC) outflow pathway. Prior studies by our laboratory reported a key role of mechanical forces and primary cilia (PC)-dependent stretch-induced autophagy in IOP homeostasis. However, the precise mechanism regulating this process remains elusive. In this study, we investigated the upstream signaling pathway orchestrating autophagy activation during cyclic mechanical stretch (CMS) in primary cultured human TM cells, using biochemical and cell biological analyses. Our results indicate that TM cells express catalytic subunits of class IA PI3Ks (PIK3CA, B, and D), and that inhibition of class IA isoforms, but not class II and III, significantly prevent CMS-induced autophagy. Importantly, PIK3CA was found to localize in the PC. Furthermore, we identified a coordinated action of Class IA PI3Ks along INPP4A/B, a 4' inositol phosphatase, responsible for the formation of PI(3,4)P2 and PI(3)P and stretch-induced autophagy in TM cells. These findings contribute to a deeper understanding of the molecular mechanisms underlying IOP homeostasis.

Understanding the conformational dynamics of PI3Kα due to helical domain mutations: insights from Markov state model analysis

Phosphoinositide 3-kinases (PI3Ks) phosphorylate phosphoinositides on the membrane, which act as secondary signals for various cellular processes. PI3Kα, a heterodimer of the p110α catalytic subunit and the p85α regulatory subunit, is activated by growth factor receptors or mutations. Among these mutations, E545K present in the helical domain is strongly associated with cancer, and is known to disrupt interactions between the regulatory and catalytic subunits, leading to its constitutive activation. However, while the mutation's role in disrupting autoinhibition is well documented, the molecular mechanisms linking this mutation in the helical domain to the structural changes in the kinase domain remain poorly understood. This study aims to understand the conformational events triggered by the E545K mutation, elucidate how these changes propagate from the helical domain to the kinase domain, and identify crucial residues involved in the activation process. Molecular dynamics (MD) simulations combined with Markov state modeling (MSM) were employed to explore the conformational landscapes of both the wild-type and mutant systems. Structural and energetic analyses, including Molecular Mechanics Poisson-Boltzmann Surface Area (MM-PBSA) calculations, revealed that the E545K mutation significantly reduces the binding affinity between the regulatory and catalytic subunits. The mutation was found to induce a sliding motion of the regulatory subunit along the catalytic subunit, leading to the disruption of key salt-bridges between these domains. This disruption releases the inhibitory effect of the regulatory subunit, resulting in increased domain motion, particularly in the adaptor-binding domain (ABD). Enhanced flexibility in the ABD, helical, and C2 domains facilitates the rearrangement of the two lobes of kinase domain, thereby promoting activation. Additionally, the mutation appears to enhance PI3Kα's membrane affinity via the Ras-binding domain (RBD). Network analysis helped to identify key residues that may involve in allosteric signaling pathways, providing insights into the communication between domains. Druggable pockets in the metastable states were predicted followed by its docking with a PI3K inhibitor library. Docking studies revealed the crucial residues that may be participating in inhibitor binding. The identification of residues and regions involved in activation mechanisms using MSM helped to reveal the conformational events and the knowledge on probable allosteric pockets, which may be helpful in designing better therapeutics.

Hepatocellular carcinoma: signaling pathways and therapeutic advances

Liver cancer represents a major global health concern, with projections indicating that the number of new cases could surpass 1 million annually by 2025. Hepatocellular carcinoma (HCC) constitutes around 90% of liver cancer cases and is primarily linked to factors incluidng aflatoxin, hepatitis B (HBV) and C (HCV), and metabolic disorders. There are no obvious symptoms in the early stage of HCC, which often leads to delays in diagnosis. Therefore, HCC patients usually present with tumors in advanced and incurable stages. Several signaling pathways are dis-regulated in HCC and cause uncontrolled cell propagation, metastasis, and recurrence of HCC. Beyond the frequently altered and therapeutically targeted receptor tyrosine kinase (RTK) pathways in HCC, pathways involved in cell differentiation, telomere regulation, epigenetic modification and stress response also provide therapeutic potential. Investigating the key signaling pathways and their inhibitors is pivotal for achieving therapeutic advancements in the management of HCC. At present, the primary therapeutic approaches for advanced HCC are tyrosine kinase inhibitors (TKI), immune checkpoint inhibitors (ICI), and combination regimens. New trials are investigating combination therapies involving ICIs and TKIs or anti-VEGF (endothelial growth factor) therapies, as well as combinations of two immunotherapy regimens. The outcomes of these trials are expected to revolutionize HCC management across all stages. Here, we provide here a comprehensive review of cellular signaling pathways, their therapeutic potential, evidence derived from late-stage clinical trials in HCC and discuss the concepts underlying earlier clinical trials, biomarker identification, and the development of more effective therapeutics for HCC.

Quinazolinones as Potential Anticancer Agents: Synthesis and Action Mechanisms

Quinazolinones, essential quinazoline derivatives, exhibit diverse biological activities with applications in pharmaceuticals and insecticides. Some derivatives have already been developed as commercial drugs. Given the rising cancer incidence, there is a critical need for new anticancer agents, and quinazolinones show promising potential in this domain. The present review focuses on novel advances in the synthesis of these important scaffolds and other medicinal aspects involving drug design, the structure-activity relationship, and action mechanisms of quinazoline and quinazolinone derivatives, to help in the development of new quinazoline and quinazolinone derivatives.

Metabolic interplays between the tumour and the host shape the tumour macroenvironment

Metabolic reprogramming of cancer cells and the tumour microenvironment are pivotal characteristics of cancers, and studying these processes offer insights and avenues for cancer diagnostics and therapeutics. Recent advancements have underscored the impact of host systemic features, termed macroenvironment, on facilitating cancer progression. During tumorigenesis, these inherent features of the host, such as germline genetics, immune profile and the metabolic status, influence how the body responds to cancer. In parallel, as cancer grows, it induces systemic effects beyond the primary tumour site and affects the macroenvironment, for example, through inflammation, the metabolic end-stage syndrome of cachexia, and metabolic dysregulation. Therefore, understanding the intricate metabolic interplay between the tumour and the host is a growing frontier in advancing cancer diagnosis and therapy. In this Review, we explore the specific contribution of the metabolic fitness of the host to cancer initiation, progression and response to therapy. We then delineate the complex metabolic crosstalk between the tumour, the microenvironment and the host, which promotes disease progression to metastasis and cachexia. The metabolic relationships among the host, cancer pathogenesis and the consequent responsive systemic manifestations during cancer progression provide new perspectives for mechanistic cancer therapy and improved management of patients with cancer.

Ablation of PI3Kγ in neurons protects mice from diet-induced obesity MASLD and insulin resistance

Mice with genetic ablation of PI3Kγ are protected from diet-induced obesity. However, the cell type responsible for PI3Kγ action in obesity remains unknown. We generated mice with conditional deletion of PI3Kγ in neurons using the nestin promoter to drive the expression of the Cre recombinase (PI3KγNest mice) and investigated their metabolic phenotype in a model of diet-induced obesity. On a chow diet, lean PI3KγNest mice display reduced linear growth and a normal metabolic phenotype. PI3KγNest mice were largely protected from diet-induced obesity and liver steatosis and showed improved glucose tolerance and insulin sensitivity. This phenotype was associated with increased phosphorylation of hormone-sensitive lipase (HSL) at protein kinase A (PKA) sites in white fat. It is concluded that PI3Kγ action in diet-induced obesity depends on its activity in neurons controlling adipose tissue lipolysis. Future clinical studies on PI3Kγ inhibitors capable of crossing the brain-blood barrier will reveal the relevance of these findings to humans.

Coffee, Phosphoinositide 3-Kinase Signaling Pathway, and Prostate Cancer: A Prospective Study in the Health Professionals Follow-Up Study

BACKGROUND

Higher coffee intake has been associated with reduced risk of prostate cancer, particularly aggressive forms. The activation of the phosphoinositide 3-kinase (PI3K) signaling pathway plays an important role in prostate carcinogenesis.

OBJECTIVE

To evaluate associations between prediagnostic coffee intake and a PI3K activation score, the expression/presence of PI3K regulators, and downstream effectors in tumor tissue from men with prostate cancer in the Health Professionals Follow-Up Study, a prospective cohort study conducted in the United States.

DESIGN

A case-only study design was applied. Coffee intake was assessed using validated food frequency questionnaires completed in 1986 and every 4 years thereafter until prostate cancer diagnosis.

PARTICIPANTS SETTING

Study participants comprised 1242 men diagnosed with prostate cancer from 1986 to 2009 and with tumor markers assessed from tissue microarrays constructed from tumor specimens.

MAIN OUTCOME MEASURES

The outcomes include the PI3K activation score; expression of insulin receptor and insulin-like growth factor 1 receptor; angiogenesis markers; and presence of the tumor suppressor phosphatase and tensin homolog, chronic and acute inflammation, simple atrophy, and post-atrophic hyperplasia.

STATISTICAL ANALYSES PERFORMED

Multivariable linear or logistic regression was conducted to estimate associations between coffee intake and tumor marker expression/presence.

RESULTS

Among coffee drinkers (86.6% of the population), median (25th, 75th percentile) coffee intake was 2 c/day (1, 3 c/day). The associations between coffee consumption and the tumor markers of interest were generally weak with modest precision. When comparing men who drank >3 c/day coffee with nondrinkers, the absolute percent difference in the PI3K activation score and angiogenesis markers ranged from 0.6% to 3.6%. The odds ratios for phosphatase and tensin homolog loss, insulin-like growth factor 1 receptor and insulin receptor expression, and presence of chronic and acute inflammation, simple atrophy, and postatrophic hyperplasia also were not statistically significant, were imprecise, and ranged from 0.82 to 1.58.

CONCLUSIONS

Coffee intake was not observed to be associated with PI3K activation, related regulators, and several effectors in prostate tumor tissue. Studies exploring alternative pathways or earlier steps in carcinogenesis are needed to investigate the underlying mechanisms of the coffee and prostate cancer association.

9. Pharmacologic Approaches to Glycemic Treatment: Standards of Care in Diabetes-2025

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, an interprofessional expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Effective Strategies for the Prevention and Mitigation of Phosphatidylinositol-3-Kinase Inhibitor-Associated Hyperglycemia: Optimizing Patient Care

Hyperglycemia is a common adverse event (AE) associated with phosphatidylinositol-3-kinase inhibitors (PI3Kis) and considered an on-target effect. Presence of hyperglycemia is associated with poor outcomes in patients with cancer, and there is need for further refinement of hyperglycemia prevention and mitigation strategies in patients receiving PI3Kis. In this review, the authors highlight effective strategies for preventing PI3Ki-induced hyperglycemia before and during treatment as well as hyperglycemia management. Prior to initiating treatment with PI3Ki, identify baseline risk factors of patients at increased risk for developing hyperglycemia, which include older age, obesity, and glycosylated hemoglobin (HbA1c) 5.7%-6.4% (prediabetes or Type 2 diabetes). To prevent new-onset hyperglycemia, optimize blood glucose, and recommend a low-carbohydrate (60-130 g/day) diet along with regular exercise to all patients prior to initiating the PI3Ki. Prophylactic metformin may be considered in all patients starting a PI3Ki with HbA1c ≤6.4%. Although existing recommendations support monitoring fasting blood glucose (FBG) once weekly (twice-weekly for intermediate-risk, daily for high-risk patients) and HbA1c every 3 months upon initiation of PI3Ki, more frequent FBG monitoring may be considered for prompt detection of hyperglycemia. Experts also recommend considering postprandial glucose monitoring because it is an early indicator of glucose intolerance. If hyperglycemia develops, metformin (first-line) and/or sodium glucose co-transporter 2 inhibitors or thiazolidinediones (second-/third-line) are the preferred agents; consider early referral to an endocrinologist. In conclusion, hyperglycemia is a common but manageable AE associated with PI3Kis. Multidisciplinary approach to the prevention, monitoring, and management of hyperglycemia optimizes patient care and allows patients to maintain therapy on PI3Ki.

A whole food, plant-based diet reduces amino acid levels in patients with metastatic breast cancer

BACKGROUND

Amino acids are critical to tumor survival. Tumors can acquire amino acids from the surrounding microenvironment, including the serum. Limiting dietary amino acids is suggested to influence their serum levels. Further, a plant-based diet is reported to contain fewer amino acids than an animal-based diet. The extent to which a plant-based diet lowers the serum levels of amino acids in patients with cancer is unclear.

METHODS

Patients with metastatic breast cancer (n = 17) were enrolled in a clinical trial with an ad libitum whole food, plant-based diet for 8 weeks without calorie or portion restriction. Dietary changes by participants were monitored using a three-day food record. Serum was collected from participants at baseline and 8 weeks. Food records and serum were analyzed for metabolic changes.

RESULTS

We found that a whole food, plant-based diet resulted in a lower intake of calories, fat, and amino acids and higher levels of fiber. Additionally, body weight, serum insulin, and IGF were reduced in participants. The diet contained lower levels of essential and non-essential amino acids, except for arginine (glutamine and asparagine were not measured). Importantly, the lowered dietary intake of amino acids translated to reduced serum levels of amino acids in participants (5/9 essential amino acids; 4/11 non-essential amino acids).

CONCLUSIONS

These findings provide a tractable approach to limiting amino acid levels in persons with cancer. This data lays a foundation for studying the relationship between amino acids in patients and tumor progression. Further, a whole-food, plant-based diet has the potential to synergize with cancer therapies that exploit metabolic vulnerabilities.

TRIAL REGISTRATION

The clinical trial was registered with ClinicalTrials.gov identifier NCT03045289 on 2017-02-07.

Recent advancements in biomarkers and molecular diagnostics in hormonal receptor-positive breast cancer

Molecular applications have limited use in breast cancer compared to other cancer types. In recent years, with an improving appreciation of the molecular genetics of breast cancer and innovative novel targeted and immune-mediated therapeutics, opportunities have arisen for more biomarker analysis and molecular applications in the diagnosis and treatment of both locally advanced and metastatic breast cancers. In hormone receptor-positive, HER2-negative breast cancers, a growing number of revolutionized personalized therapies are in clinical use or on trials, such as CDK4/6 inhibitors and immune checkpoint inhibitors in adjuvant and neoadjuvant settings, and PIK3CA inhibitors in metastatic disease. In this review, we focus on biomarkers associated with those new therapeutic targets and molecular applications for genetic alterations associated with drug resistance or interaction from a pathology perspective for selecting and optimizing breast cancer treatment.

Genomic alterations associated with resistance and circulating tumor DNA dynamics for early detection of progression on CDK4/6 inhibitor in advanced breast cancer

Combined CDK4/6 inhibitor (CDK4/6i) and endocrine therapy significantly improves outcome for patients with estrogen receptor-positive (ER+) metastatic breast cancer, but drug resistance and thus disease progression inevitably occur. Herein, we aimed to identify genomic alterations associated with combined CDK4/6i and endocrine therapy resistance, and follow the levels of specific mutations in longitudinal circulating tumor DNA (ctDNA) for early detection of progression. From a cohort of 86 patients with ER+ metastatic breast cancer we performed whole exome sequencing or targeted sequencing of paired tumor (N = 8) or blood samples (N = 5) obtained before initiation of combined CDK4/6i and endocrine therapy and at disease progression. Mutations in oncogenic genes at progression were rare, while amplifications of growth-regulating genes were more frequent. The most frequently acquired alterations observed were PIK3CA and TP53 mutations and PDK1 amplification. Longitudinal ctDNA dynamics of mutant PIK3CA or private mutations revealed increased mutation levels at progression in 8 of 10 patients (80%). Impressively, rising levels of PIK3CA-mutated ctDNA were detected 4-17 months before imaging. Our data add to the growing evidence supporting longitudinal ctDNA analysis for real-time monitoring of CDK4/6i response and early detection of progression in advanced breast cancer. Further, our analysis suggests that amplification of growth-related genes may contribute to combined CDK4/6i and endocrine therapy resistance.

Alk1/Endoglin signaling restricts vein cell size increases in response to hemodynamic cues

Hemodynamic cues are thought to control blood vessel hierarchy through a shear stress set point, where flow increases lead to blood vessel diameter expansion, while decreases in blood flow cause blood vessel narrowing. Aberrations in blood vessel diameter control can cause congenital arteriovenous malformations (AVMs). We show in zebrafish embryos that while arteries behave according to the shear stress set point model, veins do not. This behavior is dependent on distinct arterial and venous endothelial cell (EC) shapes and sizes. We show that arterial ECs enlarge more strongly when experiencing higher flow, as compared to vein cells. Through the generation of chimeric embryos, we discover that this behavior of vein cells depends on the bone morphogenetic protein (BMP) pathway components Endoglin and Alk1. Endoglin (eng) or alk1 (acvrl1) mutant vein cells enlarge when in normal hemodynamic environments, while we do not observe a phenotype in either acvrl1 or eng mutant ECs in arteries. We further show that an increase in vein diameters initiates AVMs in eng mutants, secondarily leading to higher flow to arteries. These enlarge in response to higher flow through increasing arterial EC sizes, fueling the AVM. This study thus reveals a mechanism through which BMP signaling limits vein EC size increases in response to flow and provides a framework for our understanding of how a small number of mutant vein cells via flow-mediated secondary effects on wildtype arterial ECs can precipitate larger AVMs in disease conditions, such as hereditary hemorrhagic telangiectasia (HHT).

Molecular characteristics of advanced colorectal cancer and multi-hit PIK3CA mutations

INTRODUCTION

Approximately 20% of patients living with colorectal cancer (CRC) have activating mutations in their tumors in the PIK3CA oncogene. Two or more activating mutations (multi-hit) for the PIK3CA allele increase PI3K⍺ signaling compared to single-point mutations, resulting in exceptional response to PI3K⍺ inhibition. We aimed to identify the prevalence of PIK3CA multi-hit mutations in metastatic CRC to identify patients who may benefit from PI3K inhibitors.

METHODS

The Foundation Medicine database (Boston, MA, USA) was analyzed for patients with CRC who underwent genomic profiling on tumor DNA isolated during routine clinical care from 2013 to 2021. Molecular and clinical variables were abstracted for patients with PIK3CA mutations.

RESULTS

We identified 49 051 patients with CRC who underwent Foundation Medicine testing. 710/41154 (1.7%) patients had multi-hit PIK3CA mutations, of which 53% were male (n = 448) with a median age of 60. Microsatellite status was available for 697 patients with multi-hit PIK3CA and 17.6% (123/697) were microsatellite instability-high. Clinically relevant mutations in KRAS and BRAFV600E were seen in 459/710 (64.7%) and 65/710 (9.1%), respectively. The 4 most common PIK3CA variants were H1047R (9.8%), E545K (9.2%), E542K (9.0%), and R88Q (7.1%). The most common variant pair was E542K-E545K (4.7%).

CONCLUSIONS

Multi-hit mutations in PIK3CA are seen in 1.7% of advanced CRC, a meaningful prevalence given the high burden of CRC worldwide, and may represent a subset of patients that have enhanced sensitivity to PI3K inhibition. Future investigation regarding the clinical utility of PI3K inhibitors is warranted in multi-hit PIK3CA CRC.

ATP-competitive inhibitors of PI3K enzymes demonstrate an isoform selective dual action by controlling membrane binding

PI3Kα, consisting of the p110α isoform of the catalytic subunit of PI 3-kinase (encoded by PIK3CA) and the p85α regulatory subunit (encoded by PI3KR1) is activated by growth factor receptors. The identification of common oncogenic mutations in PIK3CA has driven the development of many inhibitors that bind to the ATP-binding site in the p110α subunit. Upon activation, PI3Kα undergoes conformational changes that promote its membrane interaction and catalytic activity, yet the effects of ATP-site directed inhibitors on the PI3Kα membrane interaction are unknown. Using FRET and biolayer interferometry assays, we show that a class of ATP-site directed inhibitors represented by GSK2126458 block the growth factor activated PI3KαWT membrane interaction, an activity dependent on the ligand forming specific ATP-site interactions. The membrane interaction for hot spot oncogenic mutations that bypass normal p85α regulatory mechanisms was insensitive to GSK2126458, while GSK2126458 could regulate mutations found outside of these hot spot regions. Our data show that the effect of GSK126458 on the membrane interaction requires the enzyme to revert from its growth factor activated state to a basal state. We find that an ATP substrate analogue can increase the wild type PI3Kα membrane interaction, uncovering a substrate based regulatory event that can be mimicked by different inhibitor chemotypes. Our findings, together with the discovery of small molecule allosteric activators of PI3Kα illustrate that PI3Kα membrane interactions can be modulated by factors related to ligand binding both within the ATP site and at allosteric sites.

Targeted and cytotoxic inhibitors used in the treatment of breast cancer

Breast cancer is the most commonly diagnosed malignancy and the fifth leading cause of cancer deaths worldwide. Surgery and radiation therapy are localized therapies for early-stage and metastatic breast cancer. The management of breast cancer is determined in large part by the HER2 (human epidermal growth factor receptor 2), HR (hormone receptor), ER (estrogen receptor), and PR (progesterone receptor) status. Our views of breast cancer are evolving as its molecular hallmarks are examined, which now include immunohistochemical markers (ER, PR, HER2, and proliferation marker protein Ki-67), genomic markers (BRCA1/2 and PIK3CA), and immunomarkers (tumor-infiltrating lymphocytes and PDL1). About two-thirds of malignancies of the breast are HR-positive/HER2-negative; accordingly, endocrine-based therapy is a major treatment option for these patients. Hormonal or endocrine therapy includes selective estrogen receptor modulators (SERMs) such as raloxifene, tamoxifen and toremifene, selective estrogen-receptor degraders (SERDs) including elacestrant and fulvestrant, and aromatase inhibitors such as anastrozole, letrozole, and exemestane. A variety of cytotoxic chemotherapeutic agents are used to treat HR-negative breast cancer patients. These agents include taxanes (docetaxel, nab-paclitaxel, and paclitaxel), anthracyclines (doxorubicin, epirubicin), anti-metabolites (capecitabine, gemcitabine, fluorouracil, methotrexate), alkylating agents (carboplatin, cisplatin, and cyclophosphamide), and drugs that target microtubules (eribulin, ixabepilone, ado-trastuzumab emtansine). Patients with ER-positive tumors are treated with 5-10 years of endocrine therapy and chemotherapy. For patients with metastatic breast cancer, standard first-line and follow-up therapy options include targeted approaches such as CDK4/6 inhibitors, PI3K inhibitors, PARP inhibitors, and anti-PDL1 immunotherapy, depending on the tumor type and molecular profile.

RNF43 and ZNRF3: Versatile regulators at the membrane and their role in cancer

RNF43 and ZNRF3 are recognized as important regulators of Wnt/β-catenin signaling by maintaining Wnt-receptors at minimal essential levels. In various cancer types, particularly gastrointestinal tumors, mutations in these genes lead to abnormal Wnt-dependent activation of β-catenin signaling. However, recent findings implicate RNF43/ZNRF3 also in the regulation of other tumor-related proteins, including EGFR, BRAF, and the BMP-signaling pathway, which may have important implications for tumor biology. Additionally, we describe in detail how phosphorylation and ubiquitination may finetune RNF43 and ZNRF3 activity. We also address the variety of mutations observed in cancers and the mechanism through which they support tumor growth, and challenge the prevailing view that specific missense mutations in the R-spondin and RING domains may possess dominant-negative activity in contributing to tumor formation.

A whole food, plant-based diet reduces amino acid levels in patients with metastatic breast cancer

Background

Amino acids are critical to tumor survival. Tumors can acquire amino acids from the surrounding microenvironment, including the serum. Limiting dietary amino acids is suggested to influence their serum levels. Further, a plant-based diet is reported to contain fewer amino acids than an animal-based diet. The extent to which a plant-based diet lowers the serum levels of amino acids in patients with cancer is unclear.

Methods

Patients with metastatic breast cancer (n=17) were enrolled in a clinical trial with an ad libitum whole food, plant-based diet for 8 weeks without calorie or portion restriction. Dietary changes by participants were monitored using a three-day food record. Serum was collected from participants at baseline and 8 weeks. Food records and serum were analyzed for metabolic changes.

Results

We found that a whole food, plant-based diet resulted in a lower intake of calories, fat, and amino acids and higher levels of fiber. Additionally, body weight, serum insulin, and IGF were reduced in participants. The diet contained lower levels of essential and non-essential amino acids, except for arginine (glutamine and asparagine were not measured). Importantly, the lowered dietary intake of amino acids translated to reduced serum levels of amino acids in participants (5/9 essential amino acids; 4/11 non-essential amino acids).

Conclusions

These findings provide a tractable approach to limiting amino acid levels in persons with cancer. This data lays a foundation for studying the relationship between amino acids in patients and tumor progression. Further, a whole-food, plant-based diet has the potential to synergize with cancer therapies that exploit metabolic vulnerabilities.

Trial Registration

The clinical trial was registered with ClinicalTrials.gov identifier NCT03045289 on 2017-02-07.

The Interlinking Metabolic Association between Type 2 Diabetes Mellitus and Cancer: Molecular Mechanisms and Therapeutic Insights

Type 2 diabetes mellitus (T2DM) and cancer share common risk factors including obesity, inflammation, hyperglycemia, and hyperinsulinemia. High insulin levels activate the PI3K/Akt/mTOR signaling pathway promoting cancer cell growth, survival, proliferation, metastasis, and anti-apoptosis. The inhibition of the PI3K/Akt/mTOR signaling pathway for cancer remains a promising therapy; however, drug resistance poses a major problem in clinical settings resulting in limited efficacy of agents; thus, combination treatments with therapeutic inhibitors may solve the resistance to such agents. Understanding the metabolic link between diabetes and cancer can assist in improving the therapeutic strategies used for the management of cancer patients with diabetes and vice versa. This review provides an overview of shared molecular mechanisms between diabetes and cancer as well as discusses established and emerging therapeutic anti-cancer agents targeting the PI3K/Akt/mTOR pathway in cancer management.

A single center experience on PI3K/AKT/MTOR signaling defects: Towards pathogenicity assessment for four novel defects

BACKGROUND

Phosphoinositide 3 kinases (PI3K) are lipid kinases expressed in lymphocytes/myeloid cells. PI3K/AKT/mTOR signaling defects present with recurrent infections, autoimmunity, lymphoproliferation, and agammaglobulinemia.

OBJECTIVE

To characterize the PI3K/AKT/mTOR pathway defects and perform pathway analyses to assess novel variant pathogenicity.

METHODS

We included 12 patients (heterozygous PIK3CD (n = 9) and PIK3R1 (n = 1) (activated PI3K delta syndrome (APDS) with gain-of-function mutations) and homozygous PIK3R1 variant (n = 2)), performed clinical/laboratory/genetic evaluation, and flow cytometric PI3K/AKT/mTOR pathway analyses.

RESULTS

Median age at onset of complaints was 17.5 months (3 months to 12 years) and at diagnosis was 15.7 years (2.5-37) in APDS. Median diagnostic delay was 12.9 years (1.6-27). Recurrent respiratory tract infections (90%), lymphoproliferation (70%), autoimmune/inflammatory findings (60%), and allergy (40%) were common in APDS. Recurrent viral infections were present in 4/10 and malignancy (non-Hodgkin lymphoma and testicular yolk sac tumor) was present in 2/10 in APDS. Low CD4+ T cells(5/8) with increased CD4+ effector memory (8/8) and CD4+ TEMRA cells (6/8) were present in the given number of APDS patients. We diagnosed tubulointerstitial nephritis, Langerhans cell histiocytosis, and late-onset congenital adrenal hyperplasia in APDS. Allergic findings, lymphoproliferation/malignancy, and high IgM were present in the APDS but not in PIK3R1 deficiency. Low IgM/IgG/CD19+ B cell counts were characteristic in patients with PIK3R1 homozygous loss-of function mutations.

CONCLUSION

Differential diagnosis with combined immunodeficiency and diseases of immune dysregulation make molecular genetic analysis crucial for diagnosing mTOR pathway defects. It is easy to differentiate APDS and homozygous PIK3R1 defects with specific laboratory features. Additionally, mTOR pathway functional analysis is a definitive diagnostic and pathogenicity assessment tool for novel APDS mutations.

The molecular genetics of PI3K/PTEN/AKT/mTOR pathway in the malformations of cortical development

Malformations of cortical development (MCD) are a group of developmental disorders characterized by abnormal cortical structures caused by genetic or harmful environmental factors. Many kinds of MCD are caused by genetic variation. MCD is the common cause of intellectual disability and intractable epilepsy. With rapid advances in imaging and sequencing technologies, the diagnostic rate of MCD has been increasing, and many potential genes causing MCD have been successively identified. However, the high genetic heterogeneity of MCD makes it challenging to understand the molecular pathogenesis of MCD and to identify effective targeted drugs. Thus, in this review, we outline important events of cortical development. Then we illustrate the progress of molecular genetic studies about MCD focusing on the PI3K/PTEN/AKT/mTOR pathway. Finally, we briefly discuss the diagnostic methods, disease models, and therapeutic strategies for MCD. The information will facilitate further research on MCD. Understanding the role of the PI3K/PTEN/AKT/mTOR pathway in MCD could lead to a novel strategy for treating MCD-related diseases.

PIK3CA mutations enhance the adipogenesis of ADSCs in facial infiltrating lipomatosis through TRPV1

Facial infiltrating lipomatosis (FIL) is a congenital disorder. The pathogenesis of FIL is associated with PIK3CA mutations, but the underlying mechanisms remain undetermined. We found that the adipose tissue in FIL demonstrated adipocytes hypertrophy and increased lipid accumulation. All adipose-derived mesenchymal stem cells from FIL (FIL-ADSCs) harbored PIK3CA mutations. Moreover, FIL-ADSCs exhibited a greater capacity for adipogenesis. Knockdown of PIK3CA resulted in a reduction in the adipogenic potential of FIL-ADSCs. Furthermore, WX390, a dual-target PI3K/mTOR inhibitor, was found to impede PIK3CA-mediated adipogenesis both in vivo and in vitro. RNA sequencing (RNA-seq) revealed that the expression of transient receptor potential vanilloid subtype 1 (TRPV1) was upregulated after PI3K pathway inhibition, and overexpression or activation of TRPV1 both inhibited adipogenesis. Our study showed that PIK3CA mutations promoted adipogenesis in FIL-ADSCs and this effect was achieved by suppressing TPRV1. Pathogenesis experiments suggested that WX390 may serve as an agent for the treatment of FIL.

Lipidomics Profiling Reveals Differential Alterations after FAS Inhibition in 3D Colon Cancer Cell Culture Models

Cancerous cells synthesize most of their lipids de novo to keep up with their rapid growth and proliferation. Fatty acid synthase (FAS) is a key enzyme in the lipogenesis pathway that is upregulated in many cancers and has gained popularity as a druggable target of interest for cancer treatment. The first FAS inhibitor discovered, cerulenin, initially showed promise for chemotherapeutic purposes until it was observed that it had adverse side effects in mice. TVB-2640 (Denifanstat) is part of the newer generation of inhibitors. With multiple generations of FAS inhibitors being developed, it is vital to understand their distinct molecular downstream effects to elucidate potential interactions in the clinic. Here, we profile the lipidome of two different colorectal cancer (CRC) spheroids treated with a generation 1 inhibitor (cerulenin) or a generation 2 inhibitor (TVB-2640). We observe that the cerulenin causes drastic changes to the spheroid morphology as well as alterations to the lipid droplets found within CRC spheroids. TVB-2640 causes higher abundances of polyunsaturated fatty acids (PUFAs) whereas cerulenin causes a decreased abundance of PUFAs. The increase in PUFAs in TVB-2640 exposed spheroids indicates it is causing cells to die via a ferroptotic mechanism rather than a conventional apoptotic or necrotic mechanism.

Carbohydrate quality indices and lung cancer risk: a case-control study from Iran

Considering that carbohydrates play an important role in supplying the body with energy and exhibit diverse mechanisms that can either prevent or stimulate cancer, we hypothesize that the quality of carbohydrate intake may be associated with cancer risk, including lung cancer. This hospital-based case-control study was conducted on 135 newly diagnosed lung cancer patients, and 237 healthy age- and sex-matched hospitalized controls. We used a valid and reliable 148-item Food Frequency Questionnaire to collect the dietary intake of subjects. Multivariate logistic regression was used to estimate the association between carbohydrate quality indices and the odds of lung cancer. After adjustment for confounding variables, the high glycemic index appears to be an increased risk factor for lung cancer [odds ratio (OR) = 2.51, 95% confidence interval (CI): 1.28-4.91]. No statistically significant association was found between glycemic load and lung cancer (OR = 2.51, 95% CI: 0.98-6.43). In contrast, the carbohydrate quality index (OR = 0.23, 95% CI: 0.11-0.48) and low-carbohydrate diet score (OR = 0.17, 95% CI: 0.08-0.36), were associated with a decrease in the risk of lung cancer. In summary, our study showed that a high glycemic index is a risk factor for lung cancer, however carbohydrate quality index and low-carbohydrate diet score is a dietary approach to reduce the risk of lung cancer.

Fasting Blood Glucose-Based Novel Predictors in Detecting Metastases and Predicting Prognosis for Patients with PNENs

OBJECTIVE

To explore three novel fasting blood glucose (FBG)-based novel indicators, including the FBG-to-albumin ratio (FAR), FBG-to-lymphocytes ratio (FLR), and FBG-to-hemoglobin ratio (FHR), in predicting prognosis and detecting metastasis for patients with pancreatic neuroendocrine neoplasms (pNENs) after resection.

MATERIALS AND METHODS

A total of 178 pNENs patients who underwent surgical resection were included in this study. Receiver operating characteristic (ROC) curves were used to evaluate the diagnosis values of FAR, FLR, and FHR, and the cutoff values were obtained for further analyses. Univariate and multivariate analyses were conducted to determine the independent predictors. The Kaplan-Meier method was used to evaluate the progression-free survival (PFS) and overall survival (OS) of the pNENs patients.

RESULTS

The optimal cutoff values of FAR, FLR, and FHR were 0.17, 2.85, and 0.028, respectively. As for PFS, the area under the curve (AUC) was 0.693 for FAR, 0.690 for FLR, and 0.661 for FHR, respectively. The AUC was 0.770, 0.692, and 0.715 accordingly for OS. The groups with lower FAR, FLR, and FHR were significantly associated with prolonged PFS and OS (p < 0.05). In patients with metastasis, the lower FAR group was correlated with significantly longer PFS and OS (p = 0.022 and 0.002, respectively). The FLR was an independent predictor of PFS in pNENs patients, and the FAR was a predictor of OS. FAR was an independent indicator of PFS in patients with metastasis.

CONCLUSIONS

Preoperative FAR, FLR, and FHR are effective in predicting the prognosis of pNEN patients and detecting the synchronous metastases.

Delineation of the phenotypes and genotypes of PIK3CA-related overgrowth spectrum in East asians

PIK3CA-related overgrowth spectrum (PROS) is an umbrella term to describe a diverse range of developmental disorders. Research to date has predominantly emerged from Europe and North America, resulting in a notable scarcity of studies focusing on East Asian populations. Currently, the prevalence and distribution of PIK3CA variants across various genetic loci and their correlation with distinct phenotypes in East Asian populations remain unclear. This study aims to elucidate the phenotype-genotype correlations of PROS in East Asian populations. We presented the phenotypes and genotypes of 82 Chinese patients. Among our cohort, 67 individuals carried PIK3CA variants, including missense, frameshift, and splice variants. Six patients presented with both PIK3CA and an additional variant. Seven PIK3CA-negative patients exhibited overlapping PROS manifestations with variants in GNAQ, AKT1, PTEN, MAP3K3, GNA11, or KRAS. An integrative review of the literature pertaining to East Asian populations revealed that specific variants are uniquely associated with certain PROS phenotypes. Some rare variants were exclusively identified in cases of megalencephaly and diffuse capillary malformation with overgrowth. Non-hotspot variants with undefined oncogenicity were more common in CNS phenotypes. Diseases with vascular malformation were more likely to have variants in the helical domain, whereas phenotypes involving adipose/muscle overgrowth without vascular abnormalities predominantly presented variants in the C2 domain. Our findings underscore the unique phenotype-genotype patterns within the East Asian PROS population, highlighting the necessity for an expanded cohort to further elucidate these correlations. Such endeavors would significantly facilitate the development of PI3Kα selective inhibitors tailored for the East Asian population in the future.

Molecular mechanism analysis of nontuberculous mycobacteria infection in patients with cystic fibrosis

Aim: This study aims to explore the molecular mechanisms of cystic fibrosis (CF) complicated with nontuberculous mycobacteria (NTM) infection. Materials & methods: Expression profiles of CF with NTM-infected patients were downloaded from GEO database. Intersection analysis yielded 78 genes associated with CF with NTM infection. The protein-protein interaction (PPI) network and the functions of hub genes were investigated. Results: Five hub genes (PIK3R1, IL1A, CXCR4, ACTN1, PFN1) were identified, which were primarily enriched in actin-related biological processes and pathways. Transcription factors RELA, JUN, NFKB1 and FOS that regulated hub genes modulated IL1A expression, while 21 other transcription factors regulated CXCR4 expression. Conclusion: In summary, this study may provide new insights into the mechanisms of CF with NTM infection.

Characterizing multi-PIK3CA mutations across cancer types: Toward precision oncology

BACKGROUND

PIK3CA mutations are implicated in various cancers, but the implications of multiple concurrent mutations and their orientations within the gene have not been fully explored.

METHODS

In this study, we analyzed multi-PIK3CA mutations across a diverse pan-cancer cohort comprising 3564 tumors.

RESULTS

Multi-PIK3CA mutations were present in 10.3% of all PIK3CA-mutant tumors, predominantly occurring in breast and gynecological cancers. Notably, mutations within the helical domain (E542:E545) exclusively occurred in the trans-orientation, contrasting with mutations in the kinase ABD and C2 domains, which mainly appeared in the cis orientation.

CONCLUSIONS

The distinct pattern of mutation orientations in PIK3CA suggests variable oncogenic potential, with helical domain mutations in the trans-orientation potentially being less oncogenic. These findings highlight the importance of mutation orientation in the PIK3CA gene as potential biomarkers for targeted therapy. This understanding is crucial for designing clinical trials that leverage PI3K inhibitors, aiming for more effective and precise cancer treatment.

Quality-Assured Analysis of PIK3CA Mutations in Hormone Receptor-Positive/Human Epidermal Growth Factor Receptor 2-Negative Breast Cancer Tissue

In precision oncology, reliable testing of predictive molecular biomarkers is a prerequisite for optimal patient treatment. Interlaboratory comparisons are a crucial tool to verify diagnostic performance and reproducibility of one's approach. Herein is described the design and results of the first recurrent, internationally performed PIK3CA (phosphatidylinositol-4,5-bisphosphate 3 kinase catalytic subunit α) breast cancer tissue external quality assessment (EQA), organized by German Quality in Pathology GmbH and started in 2021. After the internal pretesting phase performed by the (lead) panel institutes, in both 2021 and 2022, each EQA test set comprised n = 10 tissue samples of hormone receptor-positive, human epidermal growth factor receptor 2-negative invasive breast cancer that had to be analyzed and reported by the participants. In 2021, the results were evaluated separately for German-speaking countries (part 1) and international laboratories (part 2). In 2022, the EQA was performed across the European Union. The EQA success rates were 84.6% (n = 11/13), 88.6% (n = 39/44), and 87.9% (n = 29/33) for EQA 2021 part 1, part 2, and EQA 2022, respectively. The most commonly used methods were next-generation sequencing and mutation-/allele-specific qualitative PCR-based assays. In summary, this recurrent PIK3CA EQA proved to be a suitable approach to obtain an international overview of methods used for PIK3CA mutation analysis, to evaluate them qualitatively, and identify the strengths and weaknesses of individual methods.

Intervention of exogenous VEGF protect brain microvascular endothelial cells from hypoxia-induced injury by regulating PLCγ/RAS/ERK and PI3K/AKT pathways

Ischemic stroke rapidly increases the expression level of vascular endothelial growth factor (VEGF), which promotes neovascularization during hypoxia. However, the effect and mechanism of VEGF intervention on cerebrovascular formation remain unclear. Therefore, our research discussed the protective effect of exogenous VEGF on cells in hypoxia environment in cerebral microvascular endothelial cells, simulating ischemic stroke in hypoxic environment. Firstly, we detected the proliferation and apoptosis of cerebral microvascular endothelial cells under hypoxia environment, as well the expression levels of VEGF-E, vascular endothelial growth factor re-ceptor-2 (VEGFR-2), BCL2, PRKCE and PINK1. Moreover, immunofluorescence and western blotting were used to verify the regulation of exogenous VEGF-E on VEGFR-2 expression in hypoxic or normal oxygen environment. Lastly, we manipulated the concentration of VEGF-E in the culture medium to investigate its impact on phospholipase Cγ1 (PLCγ1)/extracellular signaling regulatory protein kinase (ERK) -1/2 and protein kinase B (AKT) pathways. Additionally, we employed a PLCγ1 inhibitor (U73122) to investigate its impact on proliferation and PLCγ1/ERK pathways. The results show that hypoxia inhibited the proliferation of cerebral microvascular endothelial cells, promoted cell apoptosis, significantly up-regulated the expression of VEGF-E, VEGFR-2, PRKCE and PINK1, but down-regulated the expression of BCL2. Interference from exogenous VEGF-E activated PLCγ1/ERK-1/2 and AKT pathways, promoting cell proliferation and inhibiting apoptosis of hypoxic brain microvascular endothelial cells. In summary, exogenous VEGF-E prevents hypoxia-induced damage to cerebral microvascular endothelial cells by activating the PLCγ1/ERK and AKT pathways. This action inhibits the apoptosis pathway in hypoxic cerebral microvascular endothelial cells, thereby safeguarding the blood-brain barrier and the nervous system.

Transcriptome analysis of cynomolgus macaques throughout their lifespan reveals age-related immune patterns

Despite the different perspectives by diverse research sectors spanning several decades, aging research remains uncharted territory for human beings. Therefore, we investigated the transcriptomic characteristics of eight male healthy cynomolgus macaques, and the annual sampling was designed with two individuals in four age groups. As a laboratory animal, the macaques were meticulously shielded from all environmental factors except aging. The results showed recent findings of certain immune response and the age-associated network of primate immunity. Three important aging patterns were identified and each gene clusters represented a different immune response. The increased expression pattern was predominantly associated with innate immune cells, such as Neutrophils and NK cells, causing chronic inflammation with aging whereas the other two decreased patterns were associated with adaptive immunity, especially "B cell activation" affecting antibody diversity of aging. Furthermore, the hub gene network of the patterns reflected transcriptomic age and correlated with human illness status, aiding in future human disease prediction. Our macaque transcriptome profiling results offer systematic insights into the age-related immunological features of primates.

Resistance to Targeted Inhibitors of the PI3K/AKT/mTOR Pathway in Advanced Oestrogen-Receptor-Positive Breast Cancer

The PI3K/AKT/mTOR signalling pathway is one of the most frequently activated pathways in breast cancer and also plays a central role in the regulation of several physiologic functions. There are major efforts ongoing to exploit precision medicine by developing inhibitors that target the three kinases (PI3K, AKT, and mTOR). Although multiple compounds have been developed, at present, there are just three inhibitors approved to target this pathway in patients with advanced ER-positive, HER2-negative breast cancer: everolimus (mTOR inhibitor), alpelisib (PIK3CA inhibitor), and capivasertib (AKT inhibitor). Like most targeted cancer drugs, resistance poses a major problem in the clinical setting and is a factor that has frequently limited the overall efficacy of these agents. Drug resistance can be categorised into intrinsic or acquired resistance depending on the timeframe it has developed within. Whereas intrinsic resistance exists prior to a specific treatment, acquired resistance is induced by a therapy. The majority of patients with ER-positive, HER2-negative advanced breast cancer will likely be offered an inhibitor of the PI3K/AKT/mTOR pathway at some point in their cancer journey, with the options available depending on the approval criteria in place and the cancer's mutation status. Within this large cohort of patients, it is likely that most will develop resistance at some point, which makes this an area of interest and an unmet need at present. Herein, we review the common mechanisms of resistance to agents that target the PI3K/AKT/mTOR signalling pathway, elaborate on current management approaches, and discuss ongoing clinical trials attempting to mitigate this significant issue. We highlight the need for additional studies into AKT1 inhibitor resistance in particular.

Alpelisib-Induced Diabetic Ketoacidosis: A Pharmacovigilance Analysis of the FDA Adverse Event Reporting System and Review of the Literature

BACKGROUND

Alpelisib is a PI3K inhibitor indicated with fulvestrant for treatment of advanced or metastatic hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative, PIK3CA-mutated breast cancer. In the phase III SOLAR-1 trial, grade 3/4 hyperglycemic events were reported in 36.6% of patients receiving alpelisib-fulvestrant compared to 0.7% receiving placebo-fulvestrant. As case reports of diabetic ketoacidosis (DKA) have been associated with alpelisib use, the goal of this study was to characterize the FAERS reported cases of this severe adverse effect.

METHODS

A retrospective disproportionality analysis was performed using the FAERS database by calculating the reporting odds ratio (ROR) of DKA events with alpelisib from 2019 to 2022. A PubMed literature review of case reports characterizing alpelisib-induced DKA was performed.

RESULTS

Pharmacovigilance database analysis revealed significance in reporting among 87 DKA cases with alpelisib (ROR 9.84, 95% confidence interval 7.3-13.2), including hospitalization and death as reported outcomes. Review of 11 published case reports reveals median onset of DKA at 14 days with successful rechallenge possible.

CONCLUSION

Significant association with reporting exists between DKA and alpelisib exposure. We observed similar median time to onset of hyperglycemia between our analysis compared to that reported in SOLAR-1. Considering early onset of this toxicity, it is imperative that patients be closely monitored when initiating alpelisib. Addition of a preemptive antihyperglycemic or escalation in those previously on antihyperglycemic medications is beneficial in decreasing the severity of hyperglycemia with alpelisib. Further study investigating risk factors is warranted to better elucidate which patients require preemptive therapy.

Dissecting microenvironment in cystadenomas and hepatic cysts based on single nucleus RNA-sequencing data

Hepatic cystadenoma is a rare disease, accounting for about 5% of all cystic lesions, with a high tendency of malignant transformation. The preoperative diagnosis of cystadenoma is difficult, and some cystadenomas are easily misdiagnosed as hepatic cysts at first. Hepatic cyst is a relatively common liver disease, most of which are benign, but large hepatic cysts can lead to pressure on the bile duct, resulting in abnormal liver function. To better understand the difference between the microenvironment of cystadenomas and hepatic cysts, we performed single-nuclei RNA-sequencing on cystadenoma and hepatic cysts samples. In addition, we performed spatial transcriptome sequencing of hepatic cysts. Based on nucleus RNA-sequencing data, a total of seven major cell types were identified. Here we described the tumor microenvironment of cystadenomas and hepatic cysts, particularly the transcriptome signatures and regulators of immune cells and stromal cells. By inferring copy number variation, it was found that the malignant degree of hepatic stellate cells in cystadenoma was higher. Pseudotime trajectory analysis demonstrated dynamic transformation of hepatocytes in hepatic cysts and cystadenomas. Cystadenomas had higher immune infiltration than hepatic cysts, and T cells had a more complex regulatory mechanism in cystadenomas than hepatic cysts. Immunohistochemistry confirms a cystadenoma-specific T-cell immunoregulatory mechanism. These results provided a single-cell atlas of cystadenomas and hepatic cyst, revealed a more complex microenvironment in cystadenomas than in hepatic cysts, and provided new perspective for the molecular mechanisms of cystadenomas and hepatic cyst.

Metformin is a potential therapeutic for COVID-19/LUAD by regulating glucose metabolism

Lung adenocarcinoma (LUAD) is the most common and aggressive subtype of lung cancer, and coronavirus disease 2019 (COVID-19) has become a serious public health threat worldwide. Patients with LUAD and COVID-19 have a poor prognosis. Therefore, finding medications that can be used to treat COVID-19/LUAD patients is essential. Bioinformatics analysis was used to identify 20 possible metformin target genes for the treatment of COVID-19/LUAD. PTEN and mTOR may serve as hub target genes of metformin. Metformin may be able to cure COVID-19/LUAD comorbidity through energy metabolism, oxidoreductase NADH activity, FoxO signalling pathway, AMPK signalling system, and mTOR signalling pathway, among other pathways, according to the results of bioinformatic research. Metformin has ability to inhibit the proliferation of A549 cells, according to the results of colony formation and proliferation assays. In A549 cells, metformin increased glucose uptake and lactate generation, while decreasing ATP synthesis and the NAD+/NADH ratio. In summary, PTEN and mTOR may be potential targets of metformin for the treatment of COVID-19/LUAD. The mechanism by which metformin inhibits lung adenocarcinoma cell proliferation may be related to glucose metabolism regulated by PI3K/AKT signalling and mTOR signalling pathways. Our study provides a new theoretical basis for the treatment of COVID-19/LUAD.

Therapy for Hormone Receptor-Positive, Human Epidermal Growth Receptor 2-Negative Metastatic Breast Cancer Following Treatment Progression via CDK4/6 Inhibitors: A Literature Review

Endocrine therapy (ET) with a cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) is currently the first-line standard treatment for most patients with hormone receptor-positive (HR+) and human epidermal growth receptor 2-negative (HER2-) metastatic or advanced breast cancer. However, the majority of tumors response to and eventually develop resistance to CDK4/6is. The mechanisms of resistance are poorly understood, and the optimal postprogression treatment regimens and their sequences continue to evolve in the rapidly changing treatment landscape. In this review, we generally summarize the mechanisms of resistance to CDK4/6is and ET, and describe the findings from clinical trials using small molecule inhibitors, antibody-drug conjugates and immunotherapy, providing insights into how these novel strategies may reverse treatment resistance, and discussing how some have not translated into clinical benefit. Finally, we provide rational treatment strategies based on the current emerging evidence.

A real-world disproportionality analysis of FDA adverse event reporting system (FAERS) events for alpelisib

In this study, we delved into the safety profile of alpelisib, an FDA-approved treatment for hormone receptor-positive, HER2-negative, PIK3CA-mutated advanced or metastatic breast cancer, and PIK3CA-Related Overgrowth Spectrum (PROS). Despite its approval, real-world, long-term safety data is lacking. Our research scrutinizes the FDA database to assess alpelisib 's safety. We retrospectively analyzed data from April 2019 to June 2023 using four algorithms. Among 7,609,450 reports, 6692 implicated alpelisib as the primary suspected drug, uncovering adverse events (AEs) across 26 organ systems. Notably, we identified 21 previously unlisted AEs. Furthermore, differences in AEs emerged between patients with PIK3CA-mutated breast cancer and those with PROS. This study provides vital insights for healthcare professionals to navigate AEs in clinical practice and informs future research for enhancing alpelisib 's safety profile.

Serum lipidomic changes and sex differences in androgenetic alopecia

Background

Androgenetic alopecia (AGA) is the most common form of hair loss. Studies have suggested a potential link to metabolic disorders, but with conflicting results. To elucidate the lipidomics profile and sex-specific variations in AGA, while exploring correlation between AGA and metabolic syndrome (MetS).

Methods

The AGA patients (n = 83) and healthy controls (n = 84) were collected in the study. The lipid profiles were analyzed using ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Serum levels of important factors associated with AGA, namely dihydrotestosterone (DHT), prostaglandin D2 (PGD2) and transforming growth factor-β1 (TGF-β1) were quantified using ELISA.

Results

Compared with controls, AGA patients had a higher probability of MetS (26.51% vs 11.9%, P < 0.05). Fifty-one differentially expressed lipids were identified in AGA. The kind of triglyceride (TG) were significantly increased, while phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), phosphatidylinositol (PI), and phosphatidylserine (PS) exhibited remarkable decrease. PC (16:2/21:6), PC (34:4p), PE (41:7), PE (44:12), PG (40:9), PI (32:2) and TG (15:0/18:1/18:1) were identified as potential biomarkers of AGA with the highest specificity. The levels of DHT, PGD2 and TGF-β1 were significantly elevated in AGA. All seven lipids showed significant correlations with DHT, PC (34:4p) and TG (15:0/18:1/18:1) were significantly associated with PGD2, TGF-β1 displayed exclusively correlation with TG (15:0/18:1/18:1) (all P < 0.05). Furthermore, these lipids were also significantly linked to systolic blood pressure and BMI, while some of them also showed significant associations with total cholesterol and HDL-C. In subgroups, forty-two differentially expressed lipids were identified in male AGA vs male control and eighty-one in female AGA vs female control. PC (16:2/21:6) was the only specific lipids common to both sexes.

Conclusions

Aberrant lipid metabolism was observed in AGA, with distinct lipidomic profiles between male and female AGA. The potential biomarkers were closely related to DHT, PGD2, TGF-β1 and MetS-related indicators. It provides the foundation for revealing the mechanisms of AGA.

Discovery and Clinical Proof-of-Concept of RLY-2608, a First-in-Class Mutant-Selective Allosteric PI3Kα Inhibitor That Decouples Antitumor Activity from Hyperinsulinemia

PIK3CA (PI3Kα) is a lipid kinase commonly mutated in cancer, including ∼40% of hormone receptor-positive breast cancer. The most frequently observed mutants occur in the kinase and helical domains. Orthosteric PI3Kα inhibitors suffer from poor selectivity leading to undesirable side effects, most prominently hyperglycemia due to inhibition of wild-type (WT) PI3Kα. Here, we used molecular dynamics simulations and cryo-electron microscopy to identify an allosteric network that provides an explanation for how mutations favor PI3Kα activation. A DNA-encoded library screen leveraging electron microscopy-optimized constructs, differential enrichment, and an orthosteric-blocking compound led to the identification of RLY-2608, a first-in-class allosteric mutant-selective inhibitor of PI3Kα. RLY-2608 inhibited tumor growth in PIK3CA-mutant xenograft models with minimal impact on insulin, a marker of dysregulated glucose homeostasis. RLY-2608 elicited objective tumor responses in two patients diagnosed with advanced hormone receptor-positive breast cancer with kinase or helical domain PIK3CA mutations, with no observed WT PI3Kα-related toxicities.

SIGNIFICANCE

Treatments for PIK3CA-mutant cancers are limited by toxicities associated with the inhibition of WT PI3Kα. Molecular dynamics, cryo-electron microscopy, and DNA-encoded libraries were used to develop RLY-2608, a first-in-class inhibitor that demonstrates mutant selectivity in patients. This marks the advance of clinical mutant-selective inhibition that overcomes limitations of orthosteric PI3Kα inhibitors. See related commentary by Gong and Vanhaesebroeck, p. 204 . See related article by Varkaris et al., p. 227 . This article is featured in Selected Articles from This Issue, p. 201.

Therapeutic Role of Synthetic Lethality in ARID1A-Deficient Malignancies

AT-rich interaction domain 1A (ARID1A), a mammalian switch/sucrose nonfermenting complex subunit, modulates several cellular processes by regulating chromatin accessibility. It is encoded by ARID1A, an immunosuppressive gene frequently disrupted in a many tumors, affecting the proliferation, migration, and invasion of cancer cells. Targeting molecular pathways and epigenetic regulation associated with ARID1A loss, such as inhibiting the PI3K/AKT pathway or modulating Wnt/β-catenin signaling, may help suppress tumor growth and progression. Developing epigenetic drugs like histone deacetylase or DNA methyltransferase inhibitors could restore normal chromatin structure and function in cells with ARID1A loss. As ARID1A deficiency correlates with enhanced tumor mutability, microsatellite instability, high tumor mutation burden, increased programmed death-ligand 1 expression, and T-lymphocyte infiltration, ARID1A-deficient cells can be a potential therapeutic target for immune checkpoint inhibitors that warrants further exploration. In this review, we discuss the role of ARID1A in carcinogenesis, its crosstalk with other signaling pathways, and strategies to make ARID1A-deficient cells a potential therapeutic target for patients with cancer.

MCM2 is involved in subtyping and tamoxifen resistance of ERα-positive breast cancer by acting as the downstream factor of ERα

Tamoxifen (TAM) resistance is finally developed in over 40% of patients with estrogen receptor α-positive breast cancer (ERα+ -BC), documenting that discovering new molecular subtype is needed to confer perception to the heterogeneity of ERα+ -BC. We obtained representative gene sets subtyping ERα+ -BC using gene set variation analysis (GSVA), non-negative matrix factorization (NMF), and COX regression methods on the basis of METABRIC, TCGA, and GEO databases. Furthermore, the risk score of ERα+ -BC subtyping was established using least absolute shrinkage and selection operator (LASSO) regression on the basis of genes in the representative gene sets, thereby generating the two subtypes of ERα+ -BC. We further found that minichromosome maintenance complex component 2 (MCM2) functioned as the hub gene subtyping ERα+ -BC using GO, KEGG, and MCODE. MCM2 expression was capable for specifically predicting 1-year overall survival (OS) of ERα+ -BC and correlated with T stage, AJCC stage, and tamoxifen (TAM) sensitivity of ERα+ -BC. The downregulation of MCM2 expression inhibited proliferation, migration, and invasion of TAM-resistant cells and promoted G0/G1 arrest. Altogether, tamoxifen resistance entails that MCM2 is a hub gene subtyping ERα+ -BC, providing a novel dimension for discovering a potential target of TAM-resistant BC.

Immunosurveillance encounters cancer metabolism

Tumor cells reprogram nutrient acquisition and metabolic pathways to meet their energetic, biosynthetic, and redox demands. Similarly, metabolic processes in immune cells support host immunity against cancer and determine differentiation and fate of leukocytes. Thus, metabolic deregulation and imbalance in immune cells within the tumor microenvironment have been reported to drive immune evasion and to compromise therapeutic outcomes. Interestingly, emerging evidence indicates that anti-tumor immunity could modulate tumor heterogeneity, aggressiveness, and metabolic reprogramming, suggesting that immunosurveillance can instruct cancer progression in multiple dimensions. This review summarizes our current understanding of how metabolic crosstalk within tumors affects immunogenicity of tumor cells and promotes cancer progression. Furthermore, we explain how defects in the metabolic cascade can contribute to developing dysfunctional immune responses against cancers and discuss the contribution of immunosurveillance to these defects as a feedback mechanism. Finally, we highlight ongoing clinical trials and new therapeutic strategies targeting cellular metabolism in cancer.

Managing hyperglycemia and rash associated with alpelisib: expert consensus recommendations using the Delphi technique

Hyperglycemia and rash are expected but challenging adverse events of phosphatidylinositol-3-kinase inhibition (such as with alpelisib). Two modified Delphi panels were conducted to provide consensus recommendations for managing hyperglycemia and rash in patients taking alpelisib. Experts rated the appropriateness of interventions on a 1-to-9 scale; median scores and dispersion were used to classify the levels of agreement. Per the hyperglycemia panel, it is appropriate to start alpelisib in patients with HbA1c 6.5% (diabetes) to <8%, or at highest risk for developing hyperglycemia, if they have a pre-treatment endocrinology consult. Recommend prophylactic metformin in patients with baseline HbA1c 5.7% to 6.4%. Metformin is the preferred first-line anti-hyperglycemic agent. Per the rash panel, initiate prophylactic nonsedating H1 antihistamines in patients starting alpelisib. Nonsedating H1 antihistamines and topical steroids are the preferred initial management for rash. In addition to clinical trial evidence, these recommendations will help address gaps encountered in clinical practice.

Frequency of genetic alterations differs in advanced breast cancer between metastatic sites

About 20%-30% of breast cancer (BC) patients will develop distant metastases, preferentially in bones, liver, lung, and brain. BCs with different intrinsic subtypes prefer different sites for metastasis. These subtypes vary in the abundance of genetic alterations which may influence the localization of metastases. Currently, information about the relation between metastatic site and mutational profile of BC is limited. In this study, n = 521 BC metastases of the most frequently affected sites (bone, brain, liver, and lung) were investigated for the frequency of AKT1, ERBB2, ESR1, PIK3CA, and TP53 mutations via NGS and pyrosequencing. Somatic mutations were present in 64% cases. PIK3CA and TP53 were the most frequently mutated genes under study. We provide an analysis of the mutational profile of BCs and the affected metastatic site. Genetic alterations differed significantly depending on the organ site affected by metastases. TP53 mutations were mostly observed in brain metastases (51.0%), metastases outside of the brain revealed a much lower proportion of TP53 mutated samples. PIK3CA mutations are frequent in liver (40.6%), lung (36.8%), and bone metastases (35.7%), whereas less common in brain metastases (18.4%). The highest percentage of ESR1 mutations was observed in liver and lung metastases (about 30% each), whereas metastatic lesions in the brain showed significantly less ESR1 mutations, only in 2.0% of the cases. In summary, we found significant differences of mutational status in mBC depending on the affected organ and intrinsic subtype. Organotropism of metastatic cancer spread may be influenced by the mutational profile of individual BCs.

The Interplay of Lipid Signaling in Musculoskeletal Cross Talk: Implications for Health and Disease

The intricate interplay between the muscle and bone tissues is a fundamental aspect of musculoskeletal physiology. Over the past decades, emerging research has highlighted the pivotal role of lipid signaling in mediating communication between these tissues. This chapter delves into the multifaceted mechanisms through which lipids, particularly phospholipids, sphingolipids, and eicosanoids, participate in orchestrating cellular responses and metabolic pathways in both muscle and bone. Additionally, we examine the clinical implications of disrupted lipid signaling in musculoskeletal disorders, offering insights into potential therapeutic avenues. This chapter aims to shed light on the complex lipid-driven interactions between the muscle and bone tissues, paving the way for a deeper understanding of musculoskeletal health and disease.

Prognostic Value of IGFBP6 in Breast Cancer: Focus on Glucometabolism

IGFBP6, a member of the IGF binding protein (IGFBP) family, is a specific inhibitor of insulin-like growth factor II (IGF-II) and can inhibit the growth of malignant tumors overexpressing IGF-II. Type 2 diabetes (T2D) is a basic disorder of glucose metabolism that can be regulated by IGF-related pathways. We performed bioinformatics analysis of the TCGA database to explore the possible mechanism of IGFBP6 in breast cancer (BC) metabolism and prognosis and collected clinical samples from BC patients with and without T2D to compare and verify the prognostic effect of IGFBP6. In our study, the levels of IGFBP1-6 were positively correlated with overall survival (OS) in patients with breast cancer. IGFBP6 was upregulated in estrogen receptor (ER)-positive BC, and ER-positive and progesterone receptor (PR) positive patients had a higher expression level of IGFBP6 than ER-negative and PR-negative patients. IGFBP6 could be used as an independent prognostic factor in BC. The expression of IGFBP6 was decreased in BC tissue, and BC tissue from patients with T2D had lower IGFBP6 expression levels than BC tissue from patients without T2D. IGFBP6 is mainly involved in the PI3K-Akt and TGF-β signaling pathways and tumor microenvironment regulation. In terms of metabolism, the expression of IGFBP6 was negatively correlated with that of most glucose metabolism-related genes. IGFBP6 expression was mainly correlated with mutations in TP53, PIK3CA, CDH1, and MAP3K1. In addition, the upregulation of IGFBP6 in BC increased the drug sensitivity to docetaxel, paclitaxel and gemcitabine. Overall, these results indicated that high expression of IGFBP6 is associated with a good prognosis in BC patients, especially in those without T2D. It is not only involved in the maintenance of the tumor microenvironment in BC but also inhibits the energy metabolism of cancer cells through glucose metabolism-related pathways. These findings may provide a new perspective on IGFBP6 as a potential prognostic marker for BC.

Sodium-glucose cotransporter-2 inhibitors for hypergycemia in phosphoinositide 3-kinase pathway inhibition

PURPOSE

Phosphoinositide 3-kinase (PI3K) inhibition is used for the treatment of certain cancers, but can cause profound hyperglycemia and insulin resistance, for which sodium-glucose cotransporter-2 (SGLT2) inhibitors have been proposed as a preferred therapy. The objective of this research is to assess the effectiveness and safety of SGLT2 inhibitors for hyperglycemia in PI3K inhibition.

METHODS

We conducted a single-center retrospective review of adults initiating the PI3K inhibitor alpelisib. Exposure to different antidiabetic drugs and adverse events including diabetic ketoacidosis (DKA) were assessed through chart review. Plasma and point-of-care blood glucoses were extracted from the electronic medical record. Change in serum glucose and the rate of DKA on SGLT2 inhibitor versus other antidiabetic drugs were examined as co-primary outcomes.

RESULTS

We identified 103 patients meeting eligibility criteria with median follow-up of 92 days after starting alpelisib. When SGLT2 inhibitors were used to treat hyperglycemia, they were associated with a decrease in mean random glucose by -46 mg/dL (95% CI - 77 to - 15) in adjusted linear modeling. Five cases of DKA were identified, two occurring in patients on alpelisib plus SGLT2 inhibitor. Estimated incidence of DKA was: alpelisib plus SGLT2 inhibitor, 48 DKA cases per 100 patient-years (95% CI 6, 171); alpelisib with non-SGLT2 inhibitor antidiabetic drugs, 15 (95% CI 2, 53); alpelisib only, 4 (95% CI 0.1, 22).

CONCLUSIONS

SGLT2 inhibitors are effective treatments for hyperglycemia in the setting of PI3K inhibition.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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