ABSTRACT
Apoptosis is a form of programmed cell death that is mediated by intrinsic and extrinsic pathways. Dysregulation of and resistance to cell death are hallmarks of cancer. For over three decades, the development of therapies to promote treatment of cancer by inducing various cell death modalities, including apoptosis, has been a main goal of clinical oncology. Apoptosis pathways also interact with other signaling mechanisms, such as the p53 signaling pathway and the integrated stress response (ISR) pathway. In addition to agents directly targeting the intrinsic and extrinsic pathway components, anticancer drugs that target the p53 and ISR signaling pathways are actively being developed. In this Review, we discuss selected and promising anticancer therapies in various stages of development, including drug targets, mechanisms, and resistance to related treatments, focusing especially on B cell lymphoma 2 (BCL-2) inhibitors, TRAIL analogues, DR5 antibodies, and strategies that target p53, mutant p53, and the ISR.
Subject(s)
Apoptosis , Neoplasms , Signal Transduction , Tumor Suppressor Protein p53 , Humans , Neoplasms/drug therapy , Neoplasms/pathology , Neoplasms/metabolism , Neoplasms/genetics , Apoptosis/drug effects , Tumor Suppressor Protein p53/metabolism , Tumor Suppressor Protein p53/genetics , Signal Transduction/drug effects , Animals , Antineoplastic Agents/therapeutic use , Antineoplastic Agents/pharmacology , Proto-Oncogene Proteins c-bcl-2/antagonists & inhibitors , Proto-Oncogene Proteins c-bcl-2/metabolism , Proto-Oncogene Proteins c-bcl-2/geneticsABSTRACT
BACKGROUND: TROP2 (TACSTD2) expression is associated with decreased overall survival (OS) in some solid tumors, and the TROP2-targeting antibody-drug conjugate (ADC) sacituzumab govitecan has been approved in breast and urothelial carcinomas. We aimed to explore the multi-omic landscape associated with TACSTD2 gene expression in various solid tumors to identify patients most likely to benefit from this approach. METHODS: Breast (Nâ =â 11 246), colorectal (Nâ =â 15 425), hepatocellular (Nâ =â 433), pancreatic (Nâ =â 5488), and urothelial (Nâ =â 4125) tumors were stratified into quartiles by TACSTD2 gene expression, analyzed by next-generation DNA sequencing, whole transcriptome sequencing, and immunohistochemistry at Caris Life Sciences (Phoenix, AZ). Survival data were obtained from insurance claims, and Kaplan-Meier estimates were calculated for molecularly defined cohorts. RESULTS: Several pathogenic mutations were associated with TACSTD2-high tumors, including TP53 in breast, colorectal (CRC), pancreatic, and hepatocellular cancers; KRAS in pancreatic and CRC cancers; ARID1A and FGFR3 in urothelial cancer; and CTNNB1 in hepatocellular cancer. TACSTD2-low breast tumors were enriched for copy number amplifications in CCND1 and FGF/R family member genes. TACSTD2 high was generally associated with more immune cell infiltration and greater T-cell inflammation scores. Patients with TACSTD2-high breast, CRC, and pancreatic cancers demonstrated a significantly shorter OS than TACSTD2-low tumors. This was restricted to CRC with microsatellite stable tumors and patients with pancreatic cancer with KRAS-mutant tumors. Patients with breast cancer with TACSTD2-high tumors also experienced significantly worse OS following immune checkpoint inhibitors. CONCLUSIONS: TACSTD2 expression is associated with key driver alterations and a more active immune microenvironment, suggesting possible combinatorial strategies with TROP2-targeting ADCs plus immunotherapy in various solid tumors.
ABSTRACT
Single-agent TAS102 (trifluridine/tipiracil) and regorafenib are FDA-approved treatments for metastatic colorectal cancer (mCRC). We previously reported that regorafenib combined with a fluoropyrimidine can delay disease progression in clinical case reports of multidrug-resistant mCRC patients. We hypothesized that the combination of TAS102 and regorafenib may be active in CRC and other gastrointestinal (GI) cancers and may in the future provide a treatment option for patients with advanced GI cancer. We investigated the therapeutic effect of TAS102 in combination with regorafenib in preclinical studies employing cell culture, colonosphere assays that enrich for cancer stem cells, and in vivo. TAS102 in combination with regorafenib has synergistic activity against multiple GI cancers in vitro including colorectal and gastric cancer, but not liver cancer cells. TAS102 inhibits colonosphere formation and this effect is potentiated by regorafenib. In vivo anti-tumor effects of TAS102 plus regorafenib appear to be due to anti-proliferative effects, necrosis and angiogenesis inhibition. Growth inhibition by TAS102 plus regorafenib occurs in xenografted tumors regardless of p53, KRAS or BRAF mutations, although more potent tumor suppression was observed with wild-type p53. Regorafenib significantly inhibits TAS102-induced angiogenesis and microvessel density in xenografted tumors, as well inhibits TAS102-induced ERK1/2 activation regardless of RAS or BRAF status in vivo. TAS102 plus regorafenib is a synergistic drug combination in preclinical models of GI cancer, with regorafenib suppressing TAS102-induced increase in microvessel density and p-ERK as contributing mechanisms. The TAS102 plus regorafenib drug combination may be further tested in gastric and other GI cancers.
Subject(s)
Drug Combinations , Drug Synergism , Gastrointestinal Neoplasms , Mutation , Neoplastic Stem Cells , Neovascularization, Pathologic , Phenylurea Compounds , Proto-Oncogene Proteins B-raf , Proto-Oncogene Proteins p21(ras) , Pyridines , Pyrrolidines , STAT3 Transcription Factor , Thymine , Trifluridine , Uracil , Xenograft Model Antitumor Assays , Humans , Trifluridine/pharmacology , Phenylurea Compounds/pharmacology , Animals , Pyridines/pharmacology , Proto-Oncogene Proteins B-raf/genetics , Proto-Oncogene Proteins B-raf/metabolism , Proto-Oncogene Proteins p21(ras)/genetics , Proto-Oncogene Proteins p21(ras)/metabolism , Neovascularization, Pathologic/drug therapy , Neovascularization, Pathologic/genetics , Neovascularization, Pathologic/metabolism , Neoplastic Stem Cells/drug effects , Neoplastic Stem Cells/metabolism , Neoplastic Stem Cells/pathology , Gastrointestinal Neoplasms/drug therapy , Gastrointestinal Neoplasms/genetics , Gastrointestinal Neoplasms/pathology , Gastrointestinal Neoplasms/metabolism , Uracil/pharmacology , Uracil/analogs & derivatives , Mice , STAT3 Transcription Factor/metabolism , STAT3 Transcription Factor/genetics , Thymine/pharmacology , Cell Line, Tumor , Pyrrolidines/pharmacology , Pyrrolidines/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/pharmacology , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , MAP Kinase Signaling System/drug effects , Signal Transduction/drug effects , Cell Proliferation/drug effects , AngiogenesisABSTRACT
ONC201 (originally discovered as TRAIL-Inducing Compound #10 or TIC10) and analogue ONC206 have been found to induce an integrated stress response with suggested primary targets and mechanisms involving targeting mitochondrial protein ClpP and antagonism of dopamine receptors D2/3 (DRD2/3). We hypothesized that dopamine, the agonist of DRD2, may counteract ONC201 or ONC206 for DRD2/3 and impair the anti-cancer effect of ONC201 or ONC206, thus protect the tumor cells from the cytotoxic effect of ONC201 or ONC206. We therefore pre-treated cancer cells from different tissue origins including breast cancer, pancreatic cancer, colorectal cancer, and diffuse midline glioma (DMG) with dopamine, followed by treatment of ONC201, ONC206 or ONC212. We observed that 48 hours of pre-treatment with dopamine impaired the cell viability suppression effect of ONC201, ONC206 and ONC212 in pancreatic cancer cells and colorectal cancer cells. We pre-treated multiple cancer cell lines with dopamine for one week followed by ONC201, ONC206, or ONC212 treatment and performed colony assays. Pre-treatment with dopamine impaired the anti-cancer effect of ONC201 or ONC206 in pancreatic cancer and colorectal cancer. Impairment of ONC212 effect by pre-treatment with dopamine was also seen in colony assay for colorectal cancer, but not in pancreatic cancer cells by colony assay. No protection from killing by imipridones was observed with DRD2 agonist sumanirole in tumor cells, or with brain tumor cell lines pretreated with dopamine. Immunoblotting was conducted to investigate whether dopamine pre-treatment impacts signaling pathways reported to be affected by ONC201. The dopamine pre-treatment did not impact changes in ATF4, CHOP, DR5 and ClpX which were reported to be affected by ONC201. The mechanism of impairment of ONC201/206/212 effect caused by dopamine pre-treatment appears to involve upregulation of anti-apoptotic p-Bad, XIAP, FLIP and pAkt. Our results shed light on mechanisms of cancer cell protection by dopamine after imipridone treatment, heterogeneity among different tumor cell types, and suggest that effects of dopamine adaptation on tumor cells may impact on cell survival pathways in ways that may or may not depend on expression of dopamine receptors.
ABSTRACT
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and COVID-19 infection has led to worsened outcomes for patients with cancer. SARS-CoV-2 spike protein mediates host cell infection and cell-cell fusion that causes stabilization of tumor suppressor p53 protein. In-silico analysis previously suggested that SARS-CoV-2 spike interacts with p53 directly but this putative interaction has not been demonstrated in cells. We examined the interaction between SARS-CoV-2 spike, p53 and MDM2 (E3 ligase, which mediates p53 degradation) in cancer cells using an immunoprecipitation assay. We observed that SARS-CoV-2 spike protein interrupts p53-MDM2 protein interaction but did not detect SARS-CoV-2 spike bound with p53 protein in the cancer cells. We further observed that SARS-CoV-2 spike suppresses p53 transcriptional activity in cancer cells including after nutlin exposure of wild-type p53-, spike-expressing tumor cells and inhibits chemotherapy-induced p53 gene activation of p21(WAF1), TRAIL Death Receptor DR5 and MDM2. The suppressive effect of SARS-CoV-2 spike on p53-dependent gene activation provides a potential molecular mechanism by which SARS-CoV-2 infection may impact tumorigenesis, tumor progression and chemotherapy sensitivity. In fact, cisplatin-treated tumor cells expressing spike were found to have increased cell viability as compared to control cells. Further observations on γ-H2AX expression in spike-expressing cells treated with cisplatin may indicate altered DNA damage sensing in the DNA damage response pathway. The preliminary observations reported here warrant further studies to unravel the impact of SARS-CoV-2 and its various encoded proteins including spike on pathways of tumorigenesis and response to cancer therapeutics. More efforts should be directed at studying the effects of the SARS-CoV-2 spike and other viral proteins on host DNA damage sensing, response and repair mechanisms. A goal would be to understand the structural basis for maximal anti-viral immunity while minimizing suppression of host defenses including the p53 DNA damage response and tumor suppression pathway. Such directions are relevant and important including not only in the context of viral infection and mRNA vaccines in general but also for patients with cancer who may be receiving cytotoxic or other cancer treatments.
Subject(s)
Cell Survival , Cyclin-Dependent Kinase Inhibitor p21 , Proto-Oncogene Proteins c-mdm2 , Receptors, TNF-Related Apoptosis-Inducing Ligand , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Tumor Suppressor Protein p53 , Humans , Proto-Oncogene Proteins c-mdm2/metabolism , Tumor Suppressor Protein p53/metabolism , Cyclin-Dependent Kinase Inhibitor p21/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Spike Glycoprotein, Coronavirus/genetics , Cell Survival/drug effects , Receptors, TNF-Related Apoptosis-Inducing Ligand/metabolism , Receptors, TNF-Related Apoptosis-Inducing Ligand/genetics , SARS-CoV-2/physiology , Cell Line, Tumor , Neoplasms/metabolism , Neoplasms/drug therapy , Antineoplastic Agents/pharmacology , Transfection , COVID-19/virology , COVID-19/metabolismABSTRACT
Background: Immune checkpoint inhibitors alone, or in combination with chemotherapy failed to provide meaningful clinical activity for patients with microsatellite stable (MSS) colorectal cancer (CRC). ONC201 is a small molecule that inactivates AKT and ERK signaling and actives the TRAIL pathway. Preclinical studies indicated potential benefits of combining ONC201 with checkpoint inhibitors. This is a phase Ib/II trial of ONC201 plus nivolumab for patient with MSS CRC who progressed on standard treatment. Methods: Enrolled patients received ONC201 plus nivolumab in a dose de-escalation fashion to determine the maximum tolerated dose (MTD). Additional patients were enrolled in the dose-expansion cohort. ONC201 at a dose of 625 mg was given orally at day -7 of cycle 1, followed by weekly dosing. Nivolumab was given every 2 weeks at 240 mg IV starting on day 1 of every cycle (cycle =28 days). The primary end point was dose-limiting toxicity (DLT) during the observation window (run-in dose day -7, cycle 1 to assessment pre-dosing cycle 2). The plan was to enroll 28 additional patients at the MTD so that a total of 34 patients would be treated at the MTD. Pharmacokinetics (PKs) and tumor biopsies were collected at several time points per study protocol. Results: A total of 13 patients (8 patients in the dose escalation *6 evaluable*) were enrolled between December 4, 2019 and March 2021. All patients had received ≥2 previous lines of chemotherapy and had confirmed microsatellite stability or mismatch repair-proficient tumors. No DLTs were observed with 625 mg ONC201 in the first three patients. Three additional patients were enrolled at the same dose to confirm safety. Two patients progressed during the DLT period and had to be replaced. During the dose-expansion part, five patients were enrolled and none required dose reduction or modification. No objective tumor response was observed in the 13 treated patients. Disease progression was confirmed at the time of the first imaging evaluation at 8 weeks following cycle 2. Post discussion at the Data and Safety Monitoring Board (DSMB) on May 25, 2021, the principal investigator (PI) and Committee voted to close the study to new patient enrollment prior to reaching accrual of 34 patients, secondary to lack of efficacy. Conclusions: In this study of patients with advanced MSS CRC, combination ONC201/nivolumab was well-tolerated; objective responses to ONC201/nivolumab were not observed.
ABSTRACT
Prostate cancer (PCa) is a common malignancy in males. The pathology review of PCa is crucial for clinical decision-making, but traditional pathology review is labor intensive and subjective to some extent. Digital pathology and whole-slide imaging enable the application of artificial intelligence (AI) in pathology. This review highlights the success of AI in detecting and grading PCa, predicting patient outcomes, and identifying molecular subtypes. We propose that AI-based methods could collaborate with pathologists to reduce workload and assist clinicians in formulating treatment recommendations. We also introduce the general process and challenges in developing AI pathology models for PCa. Importantly, we summarize publicly available datasets and open-source codes to facilitate the utilization of existing data and the comparison of the performance of different models to improve future studies.
Subject(s)
Artificial Intelligence , Prostatic Neoplasms , Male , Humans , Clinical Decision-MakingABSTRACT
Oncogenic drivers such as KRAS extensively modulate the tumor inflammatory microenvironment (TIME) of colorectal cancer (CRC). The influence of KRAS on modulating immune cell composition remains unclear. The objective of this study was to identify signatures of infiltrative immune cells and distinctive patterns that differ between RAS wild-type (WT) and oncogenic mutant (MT) CRC that explain immune evasion in MT tumors. A total of 7,801 CRC specimens were analyzed using next-generation DNA sequencing, whole-exome sequencing, and/or whole transcriptome sequencing. Deficiency of mismatch repair (dMMR)/microsatellite instability (MSI) and tumor mutation burden (TMB) were also assessed. KRAS mutations were present in 48% of CRC, similarly distributed in patients younger than vs. 50 years and older. In microsatellite stable (MSS) KRAS MT tumors, composition of the TIME included higher neutrophil infiltration and lower infiltration of B cells. MSI-H/dMMR was significantly more prevalent in RAS WT (9.1%) than in KRAS MT (2.9%) CRC. In MSS CRC, TMB-high cases were significantly higher in RAS MT (3.1%) than in RAS WT (2.1%) tumors. KRAS and NRAS mutations are associated with increased neutrophil infiltration, with codon-specific differences. These results demonstrate significant differences in the TIME of RAS mutant CRC that match previous reports of immunoevasive characteristics of such tumors.
ABSTRACT
Immune checkpoint inhibitors (ICIs) targeting programmed cell death protein 1 or its ligand (PD-1/L1) have expanded the treatment landscape against cancers but are effective in only a subset of patients. Tumor mutation burden (TMB) is postulated to be a generic determinant of ICI-dependent tumor rejection. Here we describe the association between TMB and survival outcomes among microsatellite-stable cancers in a real-world clinicogenomic cohort consisting of 70,698 patients distributed across 27 histologies. TMB was associated with survival benefit or detriment depending on tissue and treatment context, with eight cancer types demonstrating a specific association between TMB and improved outcomes upon treatment with anti-PD-1/L1 therapies. Survival benefits were noted over a broad range of TMB cutoffs across cancer types, and a dose-dependent relationship between TMB and outcomes was observed in a subset of cancers. These results have implications for the use of cancer-agnostic and universal TMB cutoffs to guide the use of anti-PD-1/L1 therapies, and they underline the importance of tissue context in the development of ICI biomarkers.
Subject(s)
B7-H1 Antigen , Biomarkers, Tumor , Immune Checkpoint Inhibitors , Mutation , Neoplasms , Programmed Cell Death 1 Receptor , Humans , Neoplasms/genetics , Neoplasms/drug therapy , Neoplasms/immunology , Immune Checkpoint Inhibitors/therapeutic use , B7-H1 Antigen/antagonists & inhibitors , B7-H1 Antigen/genetics , Programmed Cell Death 1 Receptor/antagonists & inhibitors , Prognosis , Biomarkers, Tumor/genetics , Microsatellite Instability , Female , Microsatellite Repeats , MaleABSTRACT
Colorectal cancer (CRC) and breast cancer (BC) are deadly diseases that rank as the second and fourth leading causes of cancer-related deaths, respectively. We have previously shown that miR-6883 targets CDK4/6 and that palbociclib-mediated CDK4/6 inhibition destabilizes HIF1α. We hypothesize that miR-6883 downregulates HIF1α in CRC and BC cells. miR-6883 was transfected into cells under normoxia or hypoxia and western blot analysis revealed that miR-6883 downregulates CDK4/6 and HIF1α in CRC and BC cells, pointing to miR-6883 as a promising therapeutic to target hypoxic tumors or HIF1α-deregulated cancer cells. Future studies will further investigate miR-6883 as a cancer biomarker, effects on HIF-related proteins, and therapeutic uses in vivo .
ABSTRACT
BACKGROUND: Natural killer (NK) cells are non-antigen specific innate immune cells that can be redirected to targets of interest using multiple strategies, although none are currently FDA-approved. We sought to evaluate NK cell infiltration into tumors to develop an improved understanding of which histologies may be most amenable to NK cell-based therapies currently in the developmental pipeline. METHODS: DNA (targeted/whole-exome) and RNA (whole-transcriptome) sequencing was performed from tumors from 45 cancer types (N = 90,916 for all cancers and N = 3365 for prostate cancer) submitted to Caris Life Sciences. NK cell fractions and immune deconvolution were inferred from RNA-seq data using quanTIseq. Real-world overall survival (OS) and treatment status was determined and Kaplan-Meier estimates were calculated. Statistical significance was determined using X2 and Mann-Whitney U tests, with corrections for multiple comparisons where appropriate. RESULTS: In both a pan-tumor and prostate cancer (PCa) -specific setting, we demonstrated that NK cells represent a substantial proportion of the total cellular infiltrate (median range 2-9% for all tumors). Higher NK cell infiltration was associated with improved OS in 28 of 45 cancer types, including (PCa). NK cell infiltration was negatively correlated with common driver mutations and androgen receptor variants (AR-V7) in primary prostate biopsies, while positively correlated with negative immune regulators. Higher levels of NK cell infiltration were associated with patterns consistent with a compensatory anti-inflammatory response. CONCLUSIONS: Using the largest available dataset to date, we demonstrated that NK cells infiltrate a broad range of tumors, including both primary and metastatic PCa. NK cell infiltration is associated with improved PCa patient outcomes. This study demonstrates that NK cells are capable of trafficking to both primary and metastatic PCa and are a viable option for immunotherapy approaches moving forward. Future development of strategies to enhance tumor-infiltrating NK cell-mediated cytolytic activity and activation while limiting inhibitory pathways will be key.
ABSTRACT
Advancements in cutting-edge molecular profiling techniques, such as next-generation sequencing and bioinformatic analytic tools, have allowed researchers to examine tumour biology in detail and stratify patients based on factors linked with clinical outcome and response to therapy. This manuscript highlights the most relevant prognostic and predictive biomarkers in kidney, bladder, prostate and testicular cancers with recognised impact in clinical practice. In bladder and prostate cancer, new genetic acquisitions concerning the biology of tumours have modified the therapeutic scenario and led to the approval of target directed therapies, increasing the quality of patient care. Thus, it has become of paramount importance to choose adequate molecular tests, i.e., FGFR screening for urothelial cancer and BRCA1-2 alterations for prostate cancer, to guide the treatment plan for patients. While no tissue or blood-based biomarkers are currently used in routine clinical practice for renal cell carcinoma and testicular cancers, the field is quickly expanding. In kidney tumours, gene expression signatures might be the key to identify patients who will respond better to immunotherapy or anti-angiogenic drugs. In testicular germ cell tumours, the use of microRNA has outperformed conventional serum biomarkers in the diagnosis of primary tumours, prediction of chemoresistance, follow-up monitoring, and relapse prediction.
Subject(s)
Kidney Neoplasms , Prostatic Neoplasms , Testicular Neoplasms , Urologic Neoplasms , Male , Humans , Prognosis , Neoplasm Recurrence, Local , Urologic Neoplasms/diagnosis , Urologic Neoplasms/genetics , Kidney Neoplasms/diagnosis , Kidney Neoplasms/genetics , Biomarkers , Testicular Neoplasms/diagnosis , Testicular Neoplasms/genetics , Biomarkers, Tumor/geneticsABSTRACT
Pancreatic cancer is a devastating disease with a poor prognosis. Novel chemotherapeutics in pancreatic cancer have shown limited success, illustrating the urgent need for new treatments. Lurbinectedin (PM01183; LY-01017) received FDA approval in 2020 for metastatic small cell lung cancer on or after platinum-based chemotherapy and is currently undergoing clinical trials in a variety of tumor types. Lurbinectedin stalls and degrades RNA Polymerase II and introduces breaks in DNA, causing subsequent apoptosis. We now demonstrate lurbinectedin's highly efficient killing of human-derived pancreatic tumor cell lines PANC-1, BxPC-3, and HPAF-II as a single agent. We further demonstrate that a combination of lurbinectedin and irinotecan, a topoisomerase I inhibitor with FDA approval for advanced pancreatic cancer, results in the synergistic killing of pancreatic tumor cells. Western blot analysis of combination therapy indicates an upregulation of γH2AX, a DNA damage marker, and the Chk1/ATR pathway, which is involved in replicative stress and DNA damage response. We further demonstrate that the triple combination between lurbinectedin, irinotecan, and 5-fluorouracil (5-FU) results in a highly efficient killing of tumor cells. Our results are developing insights regarding molecular mechanisms underlying the therapeutic efficacy of a novel combination drug treatment for pancreatic cancer.
Subject(s)
Fluorouracil , Pancreatic Neoplasms , Humans , Irinotecan/pharmacology , Irinotecan/therapeutic use , Fluorouracil/pharmacology , Fluorouracil/therapeutic use , Carbolines/pharmacology , Carbolines/therapeutic use , Pancreatic Neoplasms/drug therapy , Pancreatic Neoplasms/pathology , Pancreatic NeoplasmsABSTRACT
p53 is a transcription factor that regulates the expression of genes involved in tumor suppression. p53 mutations mediate tumorigenesis and occur in approximately 50% of human cancers. p53 regulates hundreds of target genes that induce various cell fates including apoptosis, cell cycle arrest, and DNA damage repair. p53 also plays an important role in anti-tumor immunity by regulating TRAIL, DR5, TLRs, Fas, PKR, ULBP1/2, and CCL2; T-cell inhibitory ligand PD-L1; pro-inflammatory cytokines; immune cell activation state; and antigen presentation. Genetic alteration of p53 can contribute to immune evasion by influencing immune cell recruitment to the tumor, cytokine secretion in the TME, and inflammatory signaling pathways. In some contexts, p53 mutations increase neoantigen load which improves response to immune checkpoint inhibition. Therapeutic restoration of mutated p53 can restore anti-cancer immune cell infiltration and ameliorate pro-tumor signaling to induce tumor regression. Indeed, there is clinical evidence to suggest that restoring p53 can induce an anti-cancer immune response in immunologically cold tumors. Clinical trials investigating the combination of p53-restoring compounds or p53-based vaccines with immunotherapy have demonstrated anti-tumor immune activation and tumor regression with heterogeneity across cancer type. In this Review, we discuss the impact of wild-type and mutant p53 on the anti-tumor immune response, outline clinical progress as far as activating p53 to induce an immune response across a variety of cancer types, and highlight open questions limiting effective clinical translation.
ABSTRACT
Integrin receptors have long posed as a potentially attractive target for disrupting cancer hallmarks. Promising preliminary findings with integrin inhibition as an adjuvant to chemotherapy have not translated to clinical success. However, the effect of integrin inhibition on tumor-immune cell interactions remains largely unexplored. Further investigation could shed light on a connection between integrin signaling and immune checkpoint expression, opening the path for using integrin inhibitors to sensitize otherwise resistant tumors to immunotherapy. Fluorescently labeled wild-type HCT-116 colorectal cancer cells and TALL-104 T-cells were co-cultured and treated with GLPG-0187, a small molecule integrin inhibitor, at various doses. This assay revealed dose dependent cancer cell killing, indicating that integrin inhibition may be sensitizing cancer cells to immune cells. The hypothesized mechanism involves TGF-ß-mediated PD-L1 upregulation in cancer cells. To investigate this mechanism, both WT and p53-/- HCT-116 cells were pre-treated with GLPG-0187 and subsequently with latent-TGF-ß. Western blot analysis demonstrated that the addition of latent-TGF-ß increased the expression of PD-L1 in cancer cells. Additionally, a low dose of integrin inhibitor rescued these effects, returning PD-L1 expression back to control levels. This indicates that the immunostimulatory effects of integrin inhibition may be due to downregulation of immune checkpoint PD-L1 on cancer cells. It must be noted that the higher dose of the drug did not reduce PD-L1 expression. This could potentially be due to off-target effects conflicting with the proposed pathway; however, these findings are still under active investigation. Ongoing proteomic experiments will include a larger range of both drug and latent-TGF-ß doses. Probing for additional downstream markers of TGF-ß and up-stream markers of PD-L1 will help to further elucidate this mechanism. Further co-culture experiments will also include anti-PD-L1 and anti-PD-1 therapy to investigate the viability of integrin inhibition as an adjuvant to immune checkpoint blockade.
ABSTRACT
Colorectal cancer is the third leading cause of cancer-related death and the third most common cause of cancer. As the five-year survival with advanced metastatic colorectal cancer (mCRC) is 14%, new treatment strategies are needed. Immune checkpoint blockade, which takes advantage of an individual's immune system to fight cancer, has an impact in the clinic; however, for CRC, it is only effective and approved for treating mismatch repair (MMR)-deficient cancer. Moreover, long-term outcomes in MMR-deficient mCRC suggest that most patients are not cured and eventually develop therapy resistance. We hypothesized that targeting TGF-ß signaling may enhance immune-mediated T-cell killing by MMR-deficient CRC cells. Using GLPG-0187, an inhibitor of multiple integrin receptors and TGF-ß, we demonstrate minimal cytotoxicity against MMR-deficient HCT116 or p53null HCT116 human CRC cells. GLPG-0187 promoted significant immune cell killing of the CRC cells by TALL-104 T lymphoblast cells and reduced phosphoSMAD2 in HCT116 p53-null cells either in the absence or presence of exogenous TGF-ß. We observed a reduction in CCL20, CXCL5, prolactin, and TRAIL-R3, while GDF-15 was increased in TALL-104 cells treated with a T-cell activating dose of GLPG-0187 (4 µM). Our results suggest that TGF-ß signaling inhibition by a general integrin receptor inhibitor may boost T-cell killing of MMR-deficient colorectal cancer cells and suggest that a combination of anti-GDF-15 in combination with TGF-ß blockade be further investigated in the treatment of MMR-deficient mCRC. Our results support the development of a novel immune-based therapeutic strategy to treat colorectal cancer by targeting the TGF-ß signaling pathway through integrin receptor blockade.
ABSTRACT
Glycogen synthase kinase-3 (GSK-3) is a serine/threonine kinase that has been implicated in numerous oncogenic processes. GSK-3 inhibitor elraglusib (9-ING-41) has shown promising preclinical and clinical antitumor activity across multiple tumor types. Despite promising early-phase clinical trial results, there have been limited efforts to characterize the potential immunomodulatory properties of elraglusib. We report that elraglusib promotes immune cell-mediated tumor cell killing of microsatellite stable colorectal cancer (CRC) cells. Mechanistically, elraglusib sensitized CRC cells to immune-mediated cytotoxicity and enhanced immune cell effector function. Using western blots, we found that elraglusib decreased CRC cell expression of NF-κB p65 and several survival proteins. Using microarrays, we discovered that elraglusib upregulated the expression of proapoptotic and antiproliferative genes and downregulated the expression of cell proliferation, cell cycle progression, metastasis, TGFß signaling, and anti-apoptotic genes in CRC cells. Elraglusib reduced CRC cell production of immunosuppressive molecules such as VEGF, GDF-15, and sPD-L1. Elraglusib increased immune cell IFN-γ secretion, which upregulated CRC cell gasdermin B expression to potentially enhance pyroptosis. Elraglusib enhanced immune effector function resulting in augmented granzyme B, IFN-γ, TNF-α, and TRAIL production. Using a syngeneic, immunocompetent murine model of microsatellite stable CRC, we evaluated elraglusib as a single agent or combined with immune checkpoint blockade (anti-PD-1/L1) and observed improved survival in the elraglusib and anti-PD-L1 group. Murine responders had increased tumor-infiltrating T cells, augmented granzyme B expression, and fewer regulatory T cells. Murine responders had reduced immunosuppressive (VEGF, VEGFR2) and elevated immunostimulatory (GM-CSF, IL-12p70) cytokine plasma concentrations. To determine the clinical significance, we then utilized elraglusib-treated patient plasma samples and found that reduced VEGF and BAFF and elevated IL-1 beta, CCL22, and CCL4 concentrations correlated with improved survival. Using paired tumor biopsies, we found that tumor-infiltrating immune cells had a reduced expression of inhibitory immune checkpoints (VISTA, PD-1, PD-L2) and an elevated expression of T-cell activation markers (CTLA-4, OX40L) after elraglusib treatment. These results address a significant gap in knowledge concerning the immunomodulatory mechanisms of GSK-3 inhibitor elraglusib, provide a rationale for the clinical evaluation of elraglusib in combination with immune checkpoint blockade, and are expected to have an impact on additional tumor types, besides CRC.
Subject(s)
Colorectal Neoplasms , Glycogen Synthase Kinase 3 , Humans , Animals , Mice , Glycogen Synthase Kinase 3/metabolism , Granzymes/genetics , Granzymes/metabolism , Disease Models, Animal , Immune Checkpoint Inhibitors/metabolism , Vascular Endothelial Growth Factor A/metabolism , Colorectal Neoplasms/metabolism , Lymphocytes, Tumor-Infiltrating , Biopsy , Cell Line, Tumor , B7-H1 AntigenABSTRACT
Polybromo-1 (PBRM1) loss of function mutations are present in a fraction of biliary tract cancers (BTCs). PBRM1, a subunit of the PBAF chromatin-remodeling complex, is involved in DNA damage repair. Herein, we aimed to decipher the molecular landscape of PBRM1 mutated (mut) BTCs and to define potential translational aspects. Totally, 1848 BTC samples were analyzed using next-generation DNA-sequencing and immunohistochemistry (Caris Life Sciences, Phoenix, AZ). siRNA-mediated knockdown of PBRM1 was performed in the BTC cell line EGI1 to assess the therapeutic vulnerabilities of ATR and PARP inhibitors in vitro. PBRM1 mutations were identified in 8.1% (n = 150) of BTCs and were more prevalent in intrahepatic BTCs (9.9%) compared to gallbladder cancers (6.0%) or extrahepatic BTCs (4.5%). Higher rates of co-mutations in chromatin-remodeling genes (e.g., ARID1A 31% vs. 16%) and DNA damage repair genes (e.g., ATRX 4.4% vs. 0.3%) were detected in PBRM1-mutated (mut) vs. PBRM1-wildtype (wt) BTCs. No difference in real-world overall survival was observed between PBRM1-mut and PBRM1-wt patients (HR 1.043, 95% CI 0.821-1.325, p = 0.731). In vitro, experiments suggested that PARP ± ATR inhibitors induce synthetic lethality in the PBRM1 knockdown BTC model. Our findings served as the scientific rationale for PARP inhibition in a heavily pretreated PBRM1-mut BTC patient, which induced disease control. This study represents the largest and most extensive molecular profiling study of PBRM1-mut BTCs, which in vitro sensitizes to DNA damage repair inhibiting compounds. Our findings might serve as a rationale for future testing of PARP/ATR inhibitors in PBRM1-mut BTCs.
ABSTRACT
Purpose: Gene fusions involving receptor tyrosine kinases (RTKs) define an important class of genomic alterations with many successful targeted therapies now approved for ALK, ROS1, RET and NTRK gene fusions. Fusions involving the ERBB family of RTKs have been sporadically reported, but their frequency has not yet been comprehensively analyzed and functional characterization is lacking on many types of ERBB fusions. Materials and methods: We analyzed tumor samples submitted to Caris Life Sciences (n=64,354), as well as the TCGA (n=10,967), MSK IMPACT (n=10,945) and AACR GENIE (n=96,324) databases for evidence of EGFR, ERBB2 and ERBB4 gene fusions. We also expressed several novel fusions in cancer cell lines and analyzed their response to EGFR and HER2 tyrosine kinase inhibitors (TKIs). Results: In total, we identified 1,251 ERBB family fusions, representing an incidence of approximately 0.7% across all cancer types. EGFR, ERBB2, and ERBB4 fusions were most frequently found in glioblastoma, breast cancer and ovarian cancer, respectively. We modeled two novel types of EGFR and ERBB2 fusions, one with a tethered kinase domain and the other with a tethered adapter protein. Specifically, we expressed EGFR-ERBB4, EGFR-SHC1, ERBB2-GRB7 and ERBB2-SHC1, in cancer cell lines and demonstrated that they are oncogenic, regulate downstream signaling and are sensitive to small molecule inhibition with EGFR and HER2 TKIs. Conclusions: We found that ERBB fusions are recurrent mutations that occur across multiple cancer types. We also establish that adapter-tethered and kinase-tethered fusions are oncogenic and can be inhibited with EGFR or HER2 inhibitors. We further propose a nomenclature system to categorize these fusions into several functional classes.
ABSTRACT
Tumor suppressor TP53 is an important gene in human cancer because it is mutated in the majority of tumors, leading to loss-of-function or gain-of-function phenotypes. Mutated TP53 acts like an oncogene, driving cancer progression and causing poor patient outcomes. The role of mutated p53 in cancer has been known for over three decades, yet there is no FDA-approved drug to address the problem. This brief historical perspective highlights some of the insightful advances as well as challenges in therapeutic targeting of p53, especially the mutated forms. The article focuses on a functional p53 pathway restoration approach to drug discovery that years ago was not mainstream, encouraged by anyone, taught in textbooks, or embraced by medicinal chemists. With some knowledge, a clinician scientist's interest, and motivation, the author pursued a unique line of investigation leading to insights for functional bypass of TP53 mutations in human cancer. Like mutated Ras proteins, mutant p53 is fundamentally important as a therapeutic target in cancer and probably deserves a "p53 initiative" like the NCI's "Ras initiative." There is a link between naivete and enthusiasm for pursuing difficult problems, but important solutions are discovered through hard work and persistence. Hopefully, some benefit comes to patients with cancer from such drug discovery and development efforts.