In non-small cell lung cancer (NSCLC), radiotherapy not only mediates cytotoxicity but also activates radioresistance drivers like HER2. We investigated radiotherapy combined with HER2-targeted T cell therapy in an NSCLC model. The antitumor efficacy of radiotherapy and engineered T cells expressing a DAP12-associated synthetic antigen receptor (SAR) targeting HER2 was evaluated in HER2-expressing A549 xenografts. HER2 modulation, transcriptional regulation, and tumor T cell infiltration were assessed using immunoblotting, real-time quantitative polymerase chain reaction, flow cytometry, RNA-seq, and immunohistochemistry. High-dose HER2-SAR T cell infusion abolished A549 tumor growth but induced graft-vs-host disease. Low-dose T cell infusion was well-tolerated and provided partial tumor inhibition. Induction radiotherapy (7 d before T cell infusion) synergistically improved tumor control and survival. Radiotherapy transiently upregulated HER2 expression (4 to 24 h), though administering HER2-SAR T cells within this window did not enhance antitumor efficacy. Radiation did not enhance T cell-mediated cytotoxicity in vitro. However, in tumors, radiotherapy increased intratumoral proliferation and accumulation of HER2-SAR T cells and enhanced the extrinsic apoptotic pathway, including induction of Fas transcript and protein levels and cleaved caspase-3 (CC3). RNA-seq of irradiated tumors revealed lasting transcriptional reprogramming with increased immune activation and decreased proliferation and oncogenic signaling. Induction radiotherapy enhances HER2-SAR T cell infiltration and provides synergistic tumor suppression, likely through additional activation of immune-mediated apoptosis. These findings support further assessment of HER2-SAR T cell therapy in HER2-expressing NSCLC.
Androgen receptor (AR) pathway inhibitors (ARPIs) improve outcomes in advanced prostate cancer (PC) in combination with androgen deprivation therapy (ADT). However, PC rapidly develops ARPI resistance, frequently through expression of truncated AR variants (AR-Vs), like AR-V7, highlighting a need for more effective therapies. The sodium-glucose co-transporter 2 inhibitor (SGLT2i) canagliflozin, an approved diabetes drug, also suppresses PC growth and inhibits AR-related gene expression. Therefore, we hypothesized that canagliflozin may directly inhibit AR. Cellular and tumor models of PC were subjected to proliferation, clonogenic, and xenograft studies. RNA-seq and siRNA knockdown approaches defined molecular mechanisms. Molecular docking, thermal shift, and surface plasmon resonance assays assessed drug-target interactions. Stable sh-AR full-length (sh-AR-FL) and sh-AR-V7 cell lines were generated to interrogate the transcriptomic impact of AR and prognostic analysis was performed using clinical datasets. We found that canagliflozin suppresses PC growth through AR. It interacts with the AR ligand binding domain (LBD) with estimated affinity comparable to ARPIs and blocks AR signaling. Canagliflozin reduces the transcript and protein levels of the HSP70 chaperone and suppresses the cytoplasmic and nuclear levels of AR-FL and AR-Vs through proteasomal degradation. It mediates substantial reprogramming of PC transcriptional activity, including inhibition of AR pathway, cell-cycle, E2F and MYC hallmark targets. Its gene expression profile overlaps with silencing AR-FL or AR-V7 is associated with improved prognosis in clinical datasets. The results of this study demonstrate the potential for canagliflozin to function as a clinically useful ARPI and support prospective clinical investigation of this drug in PC.
Background & Aims:Metabolic dysfunction-associated steatohepatitis (MASH) is a growing cause of hepatocellular carcinoma (HCC) worldwide. The complex microenvironment of these tumors, characterized by metabolic dysfunction, hypoxia, steatosis, and fibrosis, limits the effectiveness of standard-of-care therapies, such as the multi-tyrosine kinase inhibitor lenvatinib (LEN). Salsalate (SAL), is a rheumatoid arthritis therapy that enhances fatty acid oxidation and reduces de novo lipogenesis, fibrosis and cell proliferation pathways. We hypothesize that addition of SAL could improve the efficacy of LEN in MASH-HCC. Methods:We assessed the efficacy of combination therapy using clinically relevant concentrations of LEN and SAL in human HCC cell models, orthotopic xenograft and MASH-HCC mouse models. In addition, assays assessing fatty acid oxidation and lipogenesis, protein immunoblotting and RNA-sequencing were used to understand mechanisms involved. Results:LEN + SAL synergistically suppressed the proliferation and clonogenic survival of cells (p ≤0.0001), prolonged survival in an orthotopic xenograft model (p = 0.02), and reduced angiogenesis, fibrosis, and steatosis (p ≤0.05) in a MASH-HCC model. These effects were associated with activation of AMPK and inhibition of the mTOR-HIF1α and Erk1/2 signaling pathways. RNA-sequencing analysis in both Hep3B cells and livers of the MASH-HCC mouse model revealed that SAL enhanced fatty acid oxidation and suppressed fibrosis and cell cycle progression, while LEN reduced angiogenesis with regulatory network analysis, suggesting a potential role for activating transcription factor 3 (ATF3) and ETS-proto-oncogene-1 (ETS-1). Conclusions:These data indicate that combining LEN and SAL, which exert distinct effects leading to improvements in the liver microenvironment (steatosis, angiogenesis, and fibrosis) and inhibition of tumor proliferation, may have therapeutic potential for MASH-driven HCC. Impact and implications:Although rates of MASH-HCC are on the rise globally, standard-of-care multi-tyrosine kinase inhibitors and immunotherapy have limited efficacy in this HCC etiology. Metabolic targeting with SAL inhibits cancer growth kinetics while also alleviating drivers of MASH by increasing fatty acid oxidation and reducing de novo lipogenesis and fibrosis. Combined LEN and SAL improved survival and MASH-HCC pathology in mouse models without adverse effects. Given that SAL is a safe, economical, and approved medication, this concept holds great translational potential that could provide a new treatment avenue for patients with unresected MASH-HCC.
Metabolic dysregulation is an early event in carcinogenesis. Here, we examined the expression of enzymes involved in de novo lipogenesis (ATP-citrate lyase: ACLY), glucose uptake (Glucose Transporter 1: GLUT1), and folate–glutamate metabolism (Prostate-Specific Membrane Antigen: PSMA) as potential biomarkers of risk for early prostate cancer progression. Patients who were managed initially on active surveillance with a Gleason score of 6 or a low-volume Gleason score of 7 (3 + 4) were accrued from a prostate cancer diagnostic assessment program. Patients were asked to donate their baseline diagnostic biopsy tissues and permit access to their clinical data. PSMA, GLUT1, and ACLY expression were examined with immunohistochemistry (IHC) in baseline biopsies, quantitated by Histologic Score for expression in benign and malignant glands, and compared with patient time remaining on active surveillance (time-on-AS). All three markers showed trends for elevated expression in malignant compared to benign glands, which was statistically significant for ACLY. On univariate analysis, increased PSMA and GLUT1 expression in malignant glands was associated with shorter time-on-AS (HR: 5.06, [CI 95%: 1.83–13.94] and HR: 2.44, [CI 95%: 1.10–5.44], respectively). Malignant ACLY and benign gland PSMA and GLUT1 expression showed non-significant trends for such association. On multivariate analysis, overexpression of PSMA in malignant glands was an independent predictor of early PC progression (p = 0.006). This work suggests that the expression of metabolic enzymes determined by IHC on baseline diagnostic prostate biopsies may have value as biomarkers of risk for rapid PC progression. PSMA may be an independent predictor of risk for progression and should be investigated further in systematic studies.
Non‐small cell lung cancer (NSCLC) has a poor prognosis, and effective therapeutic strategies are lacking. The diabetes drug canagliflozin inhibits NSCLC cell proliferation and the mammalian target of rapamycin (mTOR) pathway, which mediates cell growth and survival, but it is unclear whether this drug can enhance response rates when combined with cytotoxic therapy. Here, we evaluated the effects of canagliflozin on human NSCLC response to cytotoxic therapy in tissue cultures and xenografts. Ribonucleic acid sequencing (RNA‐seq), real‐time quantitative PCR (RT‐qPCR), metabolic function, small interfering ribonucleic acid (siRNA) knockdown, and protein expression assays were used in mechanistic analyses. We found that canagliflozin inhibited proliferation and clonogenic survival of NSCLC cells and augmented the efficacy of radiotherapy to mediate these effects and inhibit NSCLC xenograft growth. Canagliflozin treatment alone moderately inhibited mitochondrial oxidative phosphorylation and exhibited greater antiproliferative capacity than specific mitochondrial complex‐I inhibitors. The treatment downregulated genes mediating hypoxia‐inducible factor (HIF)‐1α stability, metabolism and survival, activated adenosine monophosphate‐activated protein kinase (AMPK) and inhibited mTOR, a critical activator of hypoxia‐inducible factor‐1α (HIF‐1α) signaling. HIF‐1α knockdown and stabilization experiments suggested that canagliflozin mediates antiproliferative effects, in part, through suppression of HIF‐1α. Transcriptional regulatory network analysis pinpointed histone deacetylase 2 (HDAC2), a gene suppressed by canagliflozin, as a key mediator of canagliflozin's transcriptional reprogramming. HDAC2 knockdown eliminated HIF‐1α levels and enhanced the antiproliferative effects of canagliflozin. HDAC2‐regulated genes suppressed by canagliflozin are associated with poor prognosis in several clinical NSCLC datasets. In addition, we include evidence that canagliflozin also improves NSCLC response to chemotherapy. In summary, canagliflozin may be a promising therapy to develop in combination with cytotoxic therapy in NSCLC.
Radiotherapy is a non-invasive standard treatment for prostate cancer (PC). However, PC develops radio-resistance, highlighting a need for agents to improve radiotherapy response. Canagliflozin, an inhibitor of sodium-glucose co-transporter-2, is approved for use in diabetes and heart failure, but is also shown to inhibit PC growth. However, whether canagliflozin can improve radiotherapy response in PC remains unknown. Here, we show that well-tolerated doses of canagliflozin suppress proliferation and survival of androgen-sensitive and insensitive human PC cells and tumors and sensitize them to radiotherapy. Canagliflozin blocks mitochondrial respiration, promotes AMPK activity, inhibits the MAPK and mTOR-p70S6k/4EBP1 pathways, activates cell cycle checkpoints, and inhibits proliferation in part through HIF-1α suppression. Canagliflozin mediates transcriptional reprogramming of several metabolic and survival pathways known to be regulated by ETS and E2F family transcription factors. Genes downregulated by canagliflozin are associated with poor PC prognosis. This study lays the groundwork for clinical investigation of canagliflozin in PC prevention and treatment in combination with radiotherapy.