Unlocking the therapeutic potential of rigosertib as a selective therapy for ovarian cancer.

Precision oncology seeks to exploit tumor-specific drug sensitivities. Traditionally, this is accomplished through the identification and targeting of highly recurrent mutations. This paradigm falls short in ovarian cancer where the oncogenic alterations are more diverse, necessitating an alternate approach for the identification of tumor-specific vulnerabilities.

Multi-node inhibition targeting mTORC1, mTORC2 and PI3Kα potently inhibits the PI3K/AKT/mTOR pathway in endometrial and breast cancer models.

Background: While PI3K/AKT/mTOR signalling plays a critical role in cancer, targeting this pathway with single node inhibitors has limited efficacy due to several known factors such as pathway feedback reactivation, co-occurring pathway mutations, and systemic glucose dysregulation leading to hyperinsulinemia. While multi-node inhibition approaches have shown promising clinical efficacy, they require further mechanistic characterisation.

Methods: Using models of endometrial and breast cancer, we evaluated the efficacy of a multi-node PI3K/AKT/mTOR pathway inhibitor approach utilising the dual mTORC1/mTORC2 inhibitor sapanisertib, PI3Kα inhibitor serabelisib and an insulin-supressing diet.

Epigenomic analysis identifies DTP subpopulation using HOPX to develop targeted therapy resistance in lung adenocarcinoma.

Genomic studies have identified oncogenic drivers in lung cancer, enabling effective targeted therapies. However, patients who initially respond inevitably experience regrowth. The drug-tolerant persister (DTP) stage is a key source of non-genetic resistance, yet its epigenetic regulation remains unclear.

The role of biomarkers in the management of HPV-related oropharyngeal cancer.

Purpose Of Review: Patients with HPV-related oropharyngeal cancer have very good survival outcomes but a high burden of toxicity. This has led to significant efforts to attempt to use a variety of biomarkers to select patients who are candidates for de-escalated treatment.

Recent Findings: Initially, the field used HPV status alone as a biomarker to select patients with oropharyngeal cancer for de-escalation, however, the recently presented results of NRG Oncology HN005 showed that this is an insufficient strategy to select patients for potential de-escalation as patients in that study who received 60 Gy rather than the standard 70 Gy of radiation had diminished progression-free survival.

Functional genomics pipeline identifies CRL4 inhibition for the treatment of ovarian cancer.

Background: The goal of precision oncology is to find effective therapeutics for every patient. Through the inclusion of emerging therapeutics in a high-throughput drug screening platform, our functional genomics pipeline inverts the common paradigm to identify patient populations that are likely to benefit from novel therapeutic strategies.

Approach: Utilizing drug screening data across a panel of 46 cancer cell lines from 11 tumor lineages, we identified an ovarian cancer-specific sensitivity to the first-in-class CRL4 inhibitors KH-4-43 and 33-11.

Risk of late radiation necrosis more than 5 years after stereotactic radiosurgery.

Objective: Radiation necrosis (RN) is a well-recognized late complication most commonly occurring within 2 years of stereotactic radiosurgery (SRS); however, late RN (LRN), RN occurring or recurring > 5 years after SRS, has been poorly described. This study analyzes the incidence of and risk factors for LRN occurring > 5 years after SRS.

Methods: This retrospective analysis included patients treated with linear accelerator-based SRS for tumors or arteriovenous malformations with > 5 years of clinical and serial MRI follow-up.

Epinephrine inhibits PI3Kα via the Hippo kinases.

The phosphoinositide 3-kinase p110α is an essential mediator of insulin signaling and glucose homeostasis. We interrogated the human serine, threonine, and tyrosine kinome to search for novel regulators of p110α and found that the Hippo kinases phosphorylate p110α at T1061, which inhibits its activity. This inhibitory state corresponds to a conformational change of a membrane-binding domain on p110α, which impairs its ability to engage membranes.

Obesity promotes breast epithelium DNA damage in women carrying a germline mutation in .

Obesity, defined as a body mass index (BMI) ≥ 30, is an established risk factor for breast cancer among women in the general population after menopause. Whether elevated BMI is a risk factor for women with a germline mutation in or is less clear because of inconsistent findings from epidemiological studies and a lack of mechanistic studies in this population. Here, we show that DNA damage in normal breast epithelia of women carrying a mutation is positively correlated with BMI and with biomarkers of metabolic dysfunction.

PI3King the Environment for Growth: PI3K Activation Drives Transcriptome Changes That Support Oncogenic Growth.

PI3K signaling plays an integral role in cells, coordinating the necessary alterations in cellular metabolism and programs to support survival and proliferation. In the first genome-wide analysis of alternative splicing in PIK3CA-mutant breast cancer, Ladewig and colleagues show that activating mutations in PIK3CA alter the use of known exons and splice junctions, leading to changes in gene expression and transcription factor activity that promote an oncogenic phenotype. Their work reveals a novel mechanism underlying the functional impact of PI3K signal activation in the context of breast cancer, where PIK3CA mutations are common and PI3K inhibitors are part of the standard of care.

Occipital Headache Evaluation and Rates of Migraine Assessment, Diagnosis, and Treatment in Patients Receiving Greater Occipital Nerve Blocks in an Academic Pain Clinic.

Objective: Diagnosis of patients with occipital headache can be challenging, as both primary and secondary causes must be considered. Our study assessed how often migraine is screened for, diagnosed, and treated in patients receiving greater occipital nerve blocks (GONBs) in a pain clinic.

Design: Institutional review board-approved, retrospective observational study.

Circling back to PTEN: Fumarate inhibits canonical tumor suppressor.

Ge et al. (2022) describes an inhibitory, post-translational modification of PTEN at C211 by fumarate, which offers new insight into the integration of PI3K signaling and metabolism via a potential feedforward regulatory mechanism involving a PI3K-glucose-fumarate-PTEN axis.

Patient-Derived In Vitro and In Vivo Models of Cancer.

Over the last two decades, cancer researchers have taken the promise offered by the Human Genome Project and have expanded its capacity to use sequencing to identify the genomic alterations that give rise to and sustain individual tumors. This expansion has allowed researchers to identify and target highly recurrent alterations in specific cancer contexts, such as EGFR mutations in non-small cell lung cancer (Lynch et al, N Engl J Med 350:2129-2139, 2004; Sharifnia et al., Proc Natl Acad Sci U S A 111:18661-18666, 2014), BCR-ABL translocations in chronic myeloid leukemia (Deininger, Pharmacol Rev 55:401-423.

A Functional Precision Oncology Approach to Identify Treatment Strategies for Myxofibrosarcoma Patients.

In this era of precision medicine, numerous workflows for the targeting of high-recurrent mutations in common tumor types have been developed, leaving patients with rare diseases with few options. Here, we implement a functional precision oncology approach utilizing comprehensive genomic profiling in combination with high-throughput drug screening, to identify tumor-specific drug sensitivities for patients with rare tumor types such as myxofibrosarcoma. From a patient with a high-grade myxofibrosarcoma, who was enrolled in the Englander Institute for Precision Medicine (EIPM) program, we established patient-derived 3D - and models for functional testing.

Targeting Cullin-RING E3 Ubiquitin Ligase 4 by Small Molecule Modulators.

Cullin-RING E3 ubiquitin ligase 4 (CRL4) plays an essential role in cell cycle progression. Recent efforts using high throughput screening and follow up hit-to-lead studies have led to identification of small molecules and that inhibit E3 CRL4's core ligase complex and exhibit anticancer potential. This review provides: 1) an updated perspective of E3 CRL4, including structural organization, major substrate targets and role in cancer; 2) a discussion of the challenges and strategies for finding the CRL inhibitor; and 3) a summary of the properties of the identified CRL4 inhibitors as well as a perspective on their potential utility to probe CRL4 biology and act as therapeutic agents.

Obesity-associated Adipose Stromal Cells Promote Breast Cancer Invasion Through Direct Cell Contact and ECM Remodeling.

Obesity increases the risk and worsens the prognosis for breast cancer due, in part, to altered adipose stromal cell (ASC) behavior. Whether ASCs from obese individuals increase migration of breast cancer cells relative to their lean counterparts, however, remains unclear. To test this connection, multicellular spheroids composed of MCF10A-derived tumor cell lines of varying malignant potential and lean or obese ASCs were embedded into collagen scaffolds mimicking the elastic moduli of interstitial breast adipose tissue.

Inhibitors of cullin-RING E3 ubiquitin ligase 4 with antitumor potential.

Cullin-RING (really intersting new gene) E3 ubiquitin ligases (CRLs) are the largest E3 family and direct numerous protein substrates for proteasomal degradation, thereby impacting a myriad of physiological and pathological processes including cancer. To date, there are no reported small-molecule inhibitors of the catalytic activity of CRLs. Here, we describe high-throughput screening and medicinal chemistry optimization efforts that led to the identification of two compounds, 33-11 and KH-4-43, which inhibit E3 CRL4 and exhibit antitumor potential.

Precision Targeting of -Null Triple-Negative Breast Tumors Guided by Electrophilic Metabolite Sensing.

Off-target effects continue to impede disease interventions, particularly when targeting a specific protein within a family of similar proteins, such as kinase isoforms that play tumor-subtype-specific roles in cancers. Exploiting the specific electrophilic-metabolite-sensing capability of Akt3, versus moderate or no sensing, respectively, by Akt2 and Akt1, we describe a first-in-class functionally Akt3-selective covalent inhibitor [MK-H(F)NE], wherein the electrophilic core is derived from the native reactive lipid metabolite HNE. Mechanistic profiling and pathway interrogations point to retention of the metabolite's structure-as opposed to implicit electrophilicity-as being essential for biasing isoform preference, which we found translates to tumor-subtype specificity against -null triple-negative breast cancers (TNBCs).

Insulin-PI3K signalling: an evolutionarily insulated metabolic driver of cancer.

Cancer is driven by incremental changes that accumulate, eventually leading to oncogenic transformation. Although genetic alterations dominate the way cancer biologists think about oncogenesis, growing evidence suggests that systemic factors (for example, insulin, oestrogen and inflammatory cytokines) and their intracellular pathways activate oncogenic signals and contribute to targetable phenotypes. Systemic factors can have a critical role in both tumour initiation and therapeutic responses as increasingly targeted and personalized therapeutic regimens are used to treat patients with cancer.

PIP4Ks Suppress Insulin Signaling through a Catalytic-Independent Mechanism.

Insulin stimulates the conversion of phosphatidylinositol-4,5-bisphosphate (PI(4,5)P) to phosphatidylinositol-3,4,5-trisphosphate (PI(3,4,5)P), which mediates downstream cellular responses. PI(4,5)P is produced by phosphatidylinositol-4-phosphate 5-kinases (PIP5Ks) and by phosphatidylinositol-5-phosphate 4-kinases (PIP4Ks). Here, we show that the loss of PIP4Ks (PIP4K2A, PIP4K2B, and PIP4K2C) in vitro results in a paradoxical increase in PI(4,5)P and a concomitant increase in insulin-stimulated production of PI(3,4,5)P.

Rac-Mediated Macropinocytosis of Extracellular Protein Promotes Glucose Independence in Non-Small Cell Lung Cancer.

Cancer cells can adapt to nutrient poor conditions by rewiring their metabolism and using alternate fuel sources. Identifying these adaptive metabolic pathways may provide novel targets for cancer therapy. Here, we identify a subset of non-small cell lung cancer (NSCLC) cell lines that survive in the absence of glucose by internalizing and metabolizing extracellular protein via macropinocytosis.

Publisher Correction: Suppression of insulin feedback enhances the efficacy of PI3K inhibitors.

In this Letter, author Xing Du was incorrectly listed as Du Xing; this has been corrected online.