Mitigating Cardiotoxicity Associated with Anticancer Drugs: An Updated Systematic Review.

Introduction: This systematic review investigated strategies to mitigate cardiotoxicity induced by anticancer medications, emphasizing exercise and pharmacological interventions. Methods: We systematically reviewed three randomized controlled trials, one ATOPE trial, and one retrospective cohort study. Results: Among 448 patients, exercise interventions, particularly in breast cancer patients, demonstrated significant improvements in left ventricular ejection fraction (LVEF) and cardiotoxicity prevention. Pharmacological interventions, including candesartan and carvedilol, have shown potential in reducing early DOX-induced subclinical cardiotoxicity (DISC). The protective efficacy of candesartan in alleviating DISC was greater than carvedilol and the control group. Combination therapy with lisinopril and bisoprolol effectively preserved the LVEF. A retrospective cohort study demonstrated the cardioprotective potential of sodium-glucose cotransporter-2 inhibitors in reducing cardiovascular events. Conclusion: This systematic review underscores the promise of exercise and pharmacological interventions for preserving cardiac function in cancer patients receiving chemotherapy. These findings have significant implications for enhancing the quality of care for cancer patients.

Reshaping the Tumor Microenvironment of KRASG12D Pancreatic Ductal Adenocarcinoma with Combined SOS1 and MEK Inhibition for Improved Immunotherapy Response.

KRAS inhibitors have demonstrated exciting preclinical and clinical responses, although resistance occurs rapidly. Here, we investigate the effects of KRAS-targeting therapies on the tumor microenvironment using a library of KrasG12D, p53-mutant, murine pancreatic ductal adenocarcinoma-derived cell lines (KPCY) to leverage immune-oncology combination strategies for long-term tumor efficacy. Our findings show that SOS1 and MEK inhibitors (SOS1i+MEKi) suppressed tumor growth in syngeneic models and increased intratumoral CD8+ T cells without durable responses. Single-cell RNA sequencing revealed an increase in inflammatory cancer-associated fibroblasts (iCAF), M2 macrophages, and a decreased dendritic cell (DC) quality that ultimately resulted in a highly immunosuppressive microenvironment driven by IL6+ iCAFs. Agonist CD40 treatment was effective to revert macrophage polarization and overcome the lack of mature antigen-presenting DCs after SOS1i+MEKi therapy. Treatment increased the overall survival of KPCY tumor-bearing mice. The addition of checkpoint blockade to SOS1i+MEKi combination resulted in tumor-free mice with established immune memory. Our data suggest that KRAS inhibition affects myeloid cell maturation and highlights the need for combining KRAS cancer-targeted therapy with myeloid activation to enhance and prolong antitumor effects. SIGNIFICANCE: Combination of SOS1 and MEK inhibitors increase T cell infiltration while blunting pro-immune myeloid cell maturation and highlights the need for combining KRAS cancer-targeted therapy with myeloid activation to enhance and prolong anti-tumor effects.

Is Masquelet Technique A Successful Viable Treatment In Reconstructing Large Tumor Bone Gaps in Adolescent and Adult?

Objectives: The reconstruction of large bony defect caused by tumor resection can be managed by different technique like bone graft, Masquelet technique, mega-prosthesis etc. Literature lacks studies discussing Masquelet technique in tumor cases especially pertaining to infected tumor in adults. We aimed to determine 1) How often and how fast is the bone healing achieved after resection greater than 10 cm bone in tumour patient's using Masquelet technique?, 2) Whether Masquelet technique can achieve optimum outcomes in adult infected cases too? Methods: We reviewed 154 patients of benign & malignant tumour managed by us between 2013 and 2019. Patients belonging to all the age group with infected tumor/diaphysial tumor/periarticular tumor, where single stage surgery or mega-prosthesis is not a viable option and were treated with Masquelet technique for reconstructing a bone defect of at least 10 cm were included in our study. We evaluated outcomes of eight patients for four parameters i.e. bony union, healing index, number of re-do surgeries required and limb length discrepancy. Results: Mean age of our study group was 20.25 years and patients followed for mean duration of 3.36 years. Mean bone loss after tumor resection was 13.1 cm (range = 11.5 cm to 15 cm). There was no sign of recurrence of tumor in any patient at the time of last follow up. Average time required to achieve bony union was 23.25 months (mean healing index of 1.67 months/cm). All but one patient achieved bony union. Mean limb length discrepancy seen was 1.44cm. Infected cases showed low healing index with higher percentage of re-do surgeries. Conclusion: Induced membrane technique is quick, safe and reliable alternative method of reconstruction to mega-prosthesis in cases with all age group where risk of failure of mega-prosthesis is high, either due to infection or shorter expected lifespan of prosthesis. However, obtaining union can be a difficult preposition in infected tumor cases and multiple surgeries may be required to get the desired result even after two stages. However, a comparative study with large sample size is required to further validate our results.

Dual TLR9 and PD-L1 targeting unleashes dendritic cells to induce durable antitumor immunity.

BACKGROUND: Although immune checkpoint inhibitors have been a breakthrough in clinical oncology, these therapies fail to produce durable responses in a significant fraction of patients. This lack of long-term efficacy may be due to a poor pre-existing network linking innate and adaptive immunity. Here, we present an antisense oligonucleotide (ASO)-based strategy that dually targets toll-like receptor 9 (TLR9) and programmed cell death ligand 1 (PD-L1), aiming to overcome resistance to anti-PD-L1 monoclonal therapy. METHODS: We designed a high-affinity immunomodulatory IM-TLR9:PD-L1-ASO antisense oligonucleotide (hereafter, IM-T9P1-ASO) targeting mouse PD-L1 messenger RNA and activating TLR9. Then, we performed in vitro and in vivo studies to validate the IM-T9P1-ASO activity, efficacy, and biological effects in tumors and draining lymph nodes. We also performed intravital imaging to study IM-T9P1-ASO pharmacokinetics in the tumor. RESULTS: IM-T9P1-ASO therapy, unlike PD-L1 antibody therapy, results in durable antitumor responses in multiple mouse cancer models. Mechanistically, IM-T9P1-ASO activates a state of tumor-associated dendritic cells (DCs), referred to here as DC3s, which have potent antitumor potential but express the PD-L1 checkpoint. IM-T9P1-ASO has two roles: it triggers the expansion of DC3s by engaging with TLR9 and downregulates PD-L1, thereby unleashing the antitumor functions of DC3s. This dual action leads to tumor rejection by T cells. The antitumor efficacy of IM-T9P1-ASO depends on the antitumor cytokine interleukin-12 (IL-12), produced by DC3s, and Batf3, a transcription factor required for DC development. CONCLUSIONS: By simultaneously targeting TLR9 and PD-L1, IM-T9P1-ASO amplifies antitumor responses via DC activation, leading to sustained therapeutic efficacy in mice. By highlighting differences and similarities between mouse and human DCs, this study could serve to develop similar therapeutic strategies for patients with cancer.

Accuracy of Patient-Specific, 3D-Printed Laminofacetal Based Trajectory-Guide for Pedicle Screw Placement in Subaxial Cervical and Thoracic Spine.

Background: Conventional methods of pedicle-screw placement have higher breach rates due to variations in pedicle trajectories. Objective: We studied the accuracy of patient-specific, three-dimensional (3D)-printed laminofacetal-based trajectory guide for pedicle-screw placement in the subaxial-cervical and thoracic spine. Materials and Methods: We enrolled 23 consecutive patients who underwent subaxial cervical and thoracic pedicle-screw instrumentation. They were divided into two groups: group A (cases without spinal deformity) and group B (cases with pre-existing spinal deformity). Patient-specific, 3D-printed laminofacetal-based trajectory guide for each instrumented level was designed. The accuracy of screw placement was assessed on postoperative computed tomography (CT) using the Gertzbein-Robbins grading. Results: A total of 194 pedicle screws (114 cervical and 80 thoracics) were placed using trajectory guides, of which 102 belonged to group B (34 cervical and 68 thoracics). Out of a total of 194 pedicle screws, 193 had clinically acceptable placement (grade A: 187; grade B: 6; and grade C: 1). In the cervical spine, 110 pedicle screws out of a total of 114 had grade A placement (grade B: 4). In the thoracic spine, 77 pedicle screws out of a total of 80 had grade A placement (grade B: 2; grade C: 1). Out of a total of 92 pedicle screws in group A, 90 had grade A placement, and the rest 2 had grade B breach. Similarly, 97 out of a total of 102 pedicle screws in group B were placed accurately, 4 had grade B and another had a grade C breach. Conclusions: Patient-specific, 3D-printed laminofacetal-based trajectory guide may help in accurate placement of subaxial cervical and thoracic pedicle screws. It may help reduce surgical time, blood loss, and radiation exposure.

Evaluation of vertebral shortening and interbody fusion with short segment pedicle screw fixation for unstable thoracolumbar fractures.

Background: Various operative procedures have been described for the treatment of traumatic paraplegia caused by unstable thoracolumbar fractures. We prospectively evaluated interbody fusion (IBF) with SS-PSF in these cases with regard to clinico-radiological outcome with the objectives: (1) Does IBF and short segment pedicle screw fixation (SS-PSF) prevent progression of kyphotic angle after surgery? (2) Can this procedure be safely performed in the setting of acute trauma?. Methods: Sixteen patients suffering from traumatic paraplegia caused by acute unstable thoracolumbar fractures were enrolled prospectively and underwent IBF with SS-PSF. They were evaluated for magnitude of shortening in spine, progression of kyphotic angle, and neurological improvement by American spinal injury association scale (ASIA). Results: Out of total sixteen, 14 patients were ASIA grade A and 2 were grade C, at the time of presentation. Thirteen out of these 14 remained grade A and one improved to B. Both the patients who had grade C involvement at the time of presentation improved to grade D at one-year follow-up. The mean blood loss was 750 ml (range; 650 ml-1150 ml). Mean kyphotic angle decreased from 20.6° (range; 13° to 37°) preoperatively to 6.2° (range; 3° to 10°) at postoperative day 2 (p = 0.002). Its mean value after 6 months was 6.5° (range; 3° to 11°). The procedure resulted in mean spinal column shortening of 18 mm (range; 16 mm-22 mm) in the spinal column. All the patients achieved bony union by a mean duration of 3.9 months (range; 3 months-6 months). Conclusions: IBF with SS-PSF has the shortest possible instrumented construct for thoracolumbar junction fusion done by posterior approach. The interbody fusion for unstable thoracolumbar junction fractures prevents the progression of kyphotic angle post-operatively. Level of evidence: Level 4.

Bone defect classifications in revision total knee arthroplasty, their reliability and utility: a systematic review.

BACKGROUND: There are various classification systems described in the literature for managing bone defects in revision knee arthroplasty (RTKA). We analysed the reliability and usefulness of these classification systems. QUESTIONS/PURPOSES: (1) To review and critique the various classification systems proposed for bone loss in RTKA. (2) Among all the proposed classifications which one is the most commonly used by surgeons to report their results. (3) What is the reliability of various bone defect classification systems for RTKA. In this review, we have assessed the studies validating those classifications with a detailed description of the limitations and the proposed modifications. METHODS: This systematic review was conducted following PRISMA guidelines. Pubmed/Medline, CINAHL, EMBASE, Scopus, Cochrane databases and Web of Science databases were searched using multiple search terms and MeSH terms where possible. Studies meeting inclusion criteria were assessed for statistical parameters of reliability of a classification system. RESULTS: We found 16 classification systems for bone defects in RTKA. Six studies were found evaluating a classification system with reporting their reliability parameters. Fifty-four studies were found which classified bone loss using AORI classification in their series. AORI classification is most commonly reported for classifying bone defects. Type T2B and F2B are the most common bone defects in RTKA. The average kappa value for AORI classification for femoral bone loss was 0.38 (0.27-0.50) and 0.76 (0.63-1) for tibial bone loss assessment. CONCLUSION: None of the available classification systems is reliably established in determining the bone loss and treatment plans in RTKA. Among all, AORI classification is the most widely used system in clinical practice. The reliability of AORI Classification is fair for femoral bone loss and substantial for tibial bone loss.

Targeting cancer glycosylation repolarizes tumor-associated macrophages allowing effective immune checkpoint blockade.

Immune checkpoint blockade (ICB) has substantially improved the prognosis of patients with cancer, but the majority experiences limited benefit, supporting the need for new therapeutic approaches. Up-regulation of sialic acid-containing glycans, termed hypersialylation, is a common feature of cancer-associated glycosylation, driving disease progression and immune escape through the engagement of Siglec receptors on tumor-infiltrating immune cells. Here, we show that tumor sialylation correlates with distinct immune states and reduced survival in human cancers. The targeted removal of Siglec ligands in the tumor microenvironment, using an antibody-sialidase conjugate, enhanced antitumor immunity and halted tumor progression in several murine models. Using single-cell RNA sequencing, we revealed that desialylation repolarized tumor-associated macrophages (TAMs). We also identified Siglec-E as the main receptor for hypersialylation on TAMs. Last, we found that genetic and therapeutic desialylation, as well as loss of Siglec-E, enhanced the efficacy of ICB. Thus, therapeutic desialylation represents an immunotherapeutic approach to reshape macrophage phenotypes and augment the adaptive antitumor immune response.

NK cells with tissue-resident traits shape response to immunotherapy by inducing adaptive antitumor immunity.

T cell-directed cancer immunotherapy often fails to generate lasting tumor control. Harnessing additional effectors of the immune response against tumors may strengthen the clinical benefit of immunotherapies. Here, we demonstrate that therapeutic targeting of the interferon-γ (IFN-γ)-interleukin-12 (IL-12) pathway relies on the ability of a population of natural killer (NK) cells with tissue-resident traits to orchestrate an antitumor microenvironment. In particular, we used an engineered adenoviral platform as a tool for intratumoral IL-12 immunotherapy (AdV5-IL-12) to generate adaptive antitumor immunity. Mechanistically, we demonstrate that AdV5-IL-12 is capable of inducing the expression of CC-chemokine ligand 5 (CCL5) in CD49a+ NK cells both in tumor mouse models and tumor specimens from patients with cancer. AdV5-IL-12 imposed CCL5-induced type I conventional dendritic cell (cDC1) infiltration and thus increased DC-CD8 T cell interactions. A similar observation was made for other IFN-γ-inducing therapies such as Programmed cell death 1 (PD-1) blockade. Conversely, failure to respond to IL-12 and PD-1 blockade in tumor models with low CD49a+ CXCR6+ NK cell infiltration could be overcome by intratumoral delivery of CCL5. Thus, therapeutic efficacy depends on the abundance of NK cells with tissue-resident traits and, specifically, their capacity to produce the DC chemoattractant CCL5. Our findings reveal a barrier for T cell-focused therapies and offer mechanistic insights into how T cell-NK cell-DC cross-talk can be enhanced to promote antitumor immunity and overcome resistance.

A Review on Structurally Diversified Synthesized Molecules as Monoacylglycerol Lipase Inhibitors and their Therapeutic uses.

Monoacylglycerol is a metabolic key serine hydrolase engaged in the regulation of the signalling network system of endocannabinoids, which is associated with various physiological processes like pain, inflammation, feeding cognition, and neurodegenerative diseases like Alzheimer's and Parkinson's disease. The monoacylglycerol was also found to act as a regulator and the free fatty acid provider in the proliferation of cancer cells as well as numerous aggressive tumours such as colorectal cancer, neuroblastoma, and nasopharyngeal carcinoma. It also played an important role in increasing the concentration of specific lipids derived from free fatty acids like phosphatidic acid, lysophosphatidic acid, sphingosine-1-phosphate, and prostaglandin E2. These signalling lipids are associated with cell proliferation, survival, tumour cell migration, contribution to tumour development, maturation, and metastases. In this study, we present a review on structurally diverse MAGL inhibitors, their development, and their evaluation for different pharmacological activities.

Experience, exposure, and attitudes regarding off-pump coronary artery bypass grafting techniques in US cardiothoracic surgical residents: Results of a survey.

Background: We sought to determine the current level of exposure to and interest in off-pump coronary artery bypass and beating heart surgery techniques regarding cardiothoracic surgical residents in the United States. Methods: An email survey consisting of 6 questions was sent to all cardiothoracic surgery residents of approved cardiothoracic training programs in the United States. The survey was emailed using the Qualtrics XM cloud-based survey platform. When the email responses were received, the answers to the survey questions were tabulated by the Qualtrics software and the resident's institution and year of graduation from their residency was noted. Results: Of 400 surveys sent, we received 99 responses for a response rate of 25%. A total of 78% of cardiothoracic surgery residents reported that they are at programs that do off-pump coronary artery bypass or beating heart surgery infrequently, noting that these cases are done in less than 5% of the coronary artery bypass graftings to which they are exposed. A total of 51% responded that they do not feel comfortable with off-pump coronary artery bypass grafting under any circumstances. A total of 49% reported some comfort with the technique with most of these respondents noting that they would do off-pump coronary artery bypass or beating heart surgery on a selective basis if the clinical situation arose and 4% plan to do off-pump coronary artery bypass routinely. Exposure to off-pump coronary artery bypass and beating heart surgery significantly correlated with future adoption of the technique by the cardiothoracic surgery residents. Cardiothoracic surgery residents in the lowest, middle, and highest terciles of exposure to off-pump coronary artery bypass and beating heart surgery plan to use these techniques 31%, 86%, and 75%, respectively, in selective cases when they are in independent practice. Conclusions: Over half of graduating cardiothoracic surgery residents do not feel comfortable with off-pump coronary artery bypass or beating heart surgery techniques. Exposure to these techniques in training correlates with comfort level and plans to use them in independent practice.

Plinabulin, a Distinct Microtubule-Targeting Chemotherapy, Promotes M1-Like Macrophage Polarization and Anti-tumor Immunity.

Reprogramming tumor infiltrating myeloid cells to elicit pro-inflammatory responses is an exciting therapeutic maneouver to improve anti-tumor responses. We recently demonstrated that a distinct microtubule-targeting drug, plinabulin-a clinical-stage novel agent-modulates dendritic cell maturation and enhances anti-tumor immunity. Here, we investigated the effects of plinabulin on macrophage polarization in vitro and in vivo. Plinabulin monotherapy induced significant tumor growth inhibition in mice bearing subcutaneous MC38 colon cancer. Importantly, the regressing tumors were characterized by an increase in M1-like/M2-like tumor-associated macrophages (TAM) ratio. The efficacy of plinabulin remained unaltered in T cell-deficient Rag2-/- mice, suggesting an important role of macrophages in driving the drug's anti-tumor effect. Exposure of murine and healthy human macrophages to plinabulin induced polarization toward the M1 phenotype, including increased expression of co-stimulatory molecules CD80, CD86 and pro-inflammatory cytokines IL-1ß, IL-6, and IL-12. M2-associated immunosuppressive cytokines IL-10 and IL-4 were reduced. This pro-inflammatory M1-like skewing of TAMs in response to plinabulin was dependent on the JNK pathway. Functionally, plinabulin-polarized human M1 macrophages directly killed HuT 78 tumor cells in vitro. Importantly, plinabulin induced a functional M1-like polarization of tumor infiltrating macrophages in murine tumors as well as in tumor samples from ovarian cancer patients, by preferentially triggering M1 proliferation. Our study uncovers a novel immunomodulatory effect of plinabulin in directly triggering M1 polarization and proliferation as well as promoting TAM anti-tumoral effector functions.

Fibroblast activation protein-targeted-4-1BB ligand agonist amplifies effector functions of intratumoral T cells in human cancer.

BACKGROUND: The costimulatory receptor 4-1BB (CD137, TNFRSF9) plays an important role in sustaining effective T cell immune responses and is investigated as target for cancer therapy. Systemic 4-1BB directed therapies elicit toxicity or low efficacy, which significantly hampered advancement of 4-1BB-based immunotherapy. Therefore, targeted delivery of 4-1BB agonist to the tumor side is needed for eliciting antitumor efficacy while avoiding systemic toxicity. METHODS: We analyzed the immunostimulatory properties of a fibroblast activation protein (FAP)-targeted 4-1BB agonist (FAP-4-1BBL) by assessing tumor-infiltrating lymphocytes' (TIL) activity from patients with non-small cell lung cancer and epithelial ovarian cancer. RESULTS: Combination treatment with FAP-4-1BBL and T cell receptor stimulation by either anti-CD3 or T cell bispecific antibodies significantly enhanced TIL activation and effector functions, including T cell proliferation, secretion of proinflammatory cytokines and cytotoxicity. Notably, costimulation with FAP-4-1BBL led to de novo secretion of interleukin (IL)-13. This was associated with cytokine-mediated tumor cell apoptosis, which was partially dependent on IL-13 alpha 1/2 receptors and STAT6 phosphorylation. CONCLUSIONS: Our study provides mechanistic insights into T cell stimulation induced by FAP-4-1BBL in primary human tumors and supports the investigation of FAP-4-1BBL compound in early clinical trials.

Optimized antiangiogenic reprogramming of the tumor microenvironment potentiates CD40 immunotherapy.

Cancer immunotherapies are increasingly combined with targeted therapies to improve therapeutic outcomes. We show that combination of agonistic anti-CD40 with antiangiogenic antibodies targeting 2 proangiogenic factors, vascular endothelial growth factor A (VEGFA) and angiopoietin 2 (Ang2/ANGPT2), induces pleiotropic immune mechanisms that facilitate tumor rejection in several tumor models. On the one hand, VEGFA/Ang2 blockade induced regression of the tumor microvasculature while decreasing the proportion of nonperfused vessels and reducing leakiness of the remaining vessels. On the other hand, both anti-VEGFA/Ang2 and anti-CD40 independently promoted proinflammatory macrophage skewing and increased dendritic cell activation in the tumor microenvironment, which were further amplified upon combination of the 2 treatments. Finally, combined therapy provoked brisk infiltration and intratumoral redistribution of cytotoxic CD8+ T cells in the tumors, which was mainly driven by Ang2 blockade. Overall, these nonredundant synergistic mechanisms endowed T cells with improved effector functions that were conducive to more efficient tumor control, underscoring the therapeutic potential of antiangiogenic immunotherapy in cancer.

GEF-H1 Signaling upon Microtubule Destabilization Is Required for Dendritic Cell Activation and Specific Anti-tumor Responses.

Dendritic cell (DC) activation is a critical step for anti-tumor T cell responses. Certain chemotherapeutics can influence DC function. Here we demonstrate that chemotherapy capable of microtubule destabilization has direct effects on DC function; namely, it induces potent DC maturation and elicits anti-tumor immunity. Guanine nucleotide exchange factor-H1 (GEF-H1) is specifically released upon microtubule destabilization and is required for DC activation. In response to chemotherapy, GEF-H1 drives a distinct cell signaling program in DCs dominated by the c-Jun N-terminal kinase (JNK) pathway and AP-1/ATF transcriptional response for control of innate and adaptive immune responses. Microtubule destabilization, and subsequent GEF-H1 signaling, enhances cross-presentation of tumor antigens to CD8 T cells. In absence of GEF-H1, anti-tumor immunity is hampered. In cancer patients, high expression of the GEF-H1 immune gene signature is associated with prolonged survival. Our study identifies an alternate intracellular axis in DCs induced upon microtubule destabilization in which GEF-H1 promotes protective anti-tumor immunity.

Discordant findings on preoperative imaging for primary hyperparathyroidism and thyroid disease: Choosing the path to follow.

BACKGROUND: Preoperative localization of abnormal parathyroid glands in primary hyperparathyroidism is often obtained by sestamibi, and ultrasonography. We aimed to identify which modality is most accurate when laterality of abnormal glands on preoperative imaging is discordant. METHODS: A single institution retrospective review identified 112 consecutive patients with primary hyperparathyroidism who underwent successful parathyroidectomy and sestamibi with pertechnetate. RESULTS: Sestamibi with pertechnetate had a sensitivity of 72% and positive predictive value of 90%; ultrasonography had sensitivity of 50% and positive predictive value 80%. Patients with thyroiditis had lesser sensitivity and positive predictive value on sestamibi with pertechnetate (53% and 77%, respectively), in contrast to ultrasonography (54%, 88%, respectively). The sensitivity and positive predictive value of sestamibi with pertechnetate and ultrasonography did not differ in patients with thyroid nodules. Seventeen patients (15%) had discordant laterality on preoperative imaging. In discordant cases, sestamibi with pertechnetate was correct in 53% overall but in only 17% of those with thyroiditis (P = .01), whereas ultrasonography was correct in 26% overall but in 50% of those with thyroiditis (P = .01). CONCLUSION: Thyroiditis decreased the sensitivity and positive predictive value of sestamibi with pertechnetate in primary hyperparathyroidism. In patients with discordant laterality on preoperative imaging, sestamibi with pertechnetate is the more accurate choice to guide operative planning, although ultrasonography may be a better guide in those with thyroiditis.

Antisense oligonucleotide targeting CD39 improves anti-tumor T cell immunity.

BACKGROUND: Cancer cells are known to develop mechanisms to circumvent effective anti-tumor immunity. The two ectonucleotidases CD39 and CD73 are promising drug targets, as they act in concert to convert extracellular immune-stimulating ATP to adenosine. CD39 is expressed by different immune cell populations as well as cancer cells of different tumor types and supports the tumor in escaping immune recognition and destruction. Thus, increasing extracellular ATP and simultaneously reducing adenosine concentrations in the tumor can lead to effective anti-tumor immunity. METHODS: We designed locked nucleic acid (LNA)-modified antisense oligonucleotides (ASOs) with specificity for human or mouse CD39 that do not need a transfection reagent or delivery system for efficient target knockdown. Knockdown efficacy of ASOs on mRNA and protein level was investigated in cancer cell lines and in primary human T cells. The effect of CD39 knockdown on ATP-degrading activity was evaluated by measuring levels of ATP in tumor cell supernatants and analysis of T cell proliferation in the presence of extracellular ATP. The in vivo effects of CD39-specific ASOs on target expression, anti-tumor immune responses and on tumor growth were analyzed in syngeneic mouse tumor models using multi-color flow cytometry. RESULTS: CD39-specific ASOs suppressed expression of CD39 mRNA and protein in different murine and human cancer cell lines and in primary human T cells. Degradation of extracellular ATP was strongly reduced by CD39-specific ASOs. Strikingly, CD39 knockdown by ASOs was associated with improved CD8+ T cell proliferation. Treatment of tumor-bearing mice with CD39-specific ASOs led to dose-dependent reduction of CD39-protein expression in regulatory T cells (Tregs) and tumor-associated macrophages. Moreover, frequency of intratumoral Tregs was substantially reduced in CD39 ASO-treated mice. As a consequence, the ratio of CD8+ T cells to Tregs in tumors was improved, while PD-1 expression was induced in CD39 ASO-treated intratumoral CD8+ T cells. Consequently, CD39 ASO treatment demonstrated potent reduction in tumor growth in combination with anti-PD-1 treatment. CONCLUSION: Targeting of CD39 by ASOs represents a promising state-of-the art therapeutic approach to improve immune responses against tumors.

A Variant of a Killer Cell Immunoglobulin-like Receptor Is Associated with Resistance to PD-1 Blockade in Lung Cancer.

PURPOSE: PD-(L)1-blocking antibodies have clinical activity in metastatic non-small cell lung cancer (NSCLC) and mediate durable tumor remissions. However, the majority of patients are resistant to PD-(L)1 blockade. Understanding mechanisms of primary resistance may allow prediction of clinical response and identification of new targetable pathways. EXPERIMENTAL DESIGN: Peripheral blood mononuclear cells were collected from 35 patients with NSCLC receiving nivolumab monotherapy. Cellular changes, cytokine levels, gene expression, and polymorphisms were compared between responders and nonresponders to treatment. Findings were confirmed in additional cohorts of patients with NSCLC receiving immune checkpoint blockade. RESULTS: We identified a genetic variant of a killer cell immunoglobulin-like receptor (KIR) KIR3DS1 that is associated with primary resistance to PD-1 blockade in patients with NSCLC. This association could be confirmed in independent cohorts of patients with NSCLC. In a multivariate analysis of the pooled cohort of 135 patients, the progression-free survival was significantly associated with presence of the KIR3DS1 allele (HR, 1.72; 95% confidence interval, 1.10-2.68; P = 0.017). No relationship was seen in cohorts of patients with NSCLC who did not receive immunotherapy. Cellular assays from patients before and during PD-1 blockade showed that resistance may be due to NK-cell dysfunction. CONCLUSIONS: We identified an association of the KIR3DS1 allelic variant with response to PD-1-targeted immunotherapy in patients with NSCLC. This finding links NK cells with response to PD-1 therapy. Although the findings are interesting, a larger analysis in a randomized trial will be needed to confirm KIRs as predictive markers for response to PD-1-targeted immunotherapy.

A novel anti-HER2 anthracycline-based antibody-drug conjugate induces adaptive anti-tumor immunity and potentiates PD-1 blockade in breast cancer.

Increasing evidence suggests that antibody-drug conjugates (ADCs) can enhance anti-tumor immunity and improve clinical outcome. Here, we elucidate the therapeutic efficacy and immune-mediated mechanisms of a novel HER2-targeting ADC bearing a potent anthracycline derivate as payload (T-PNU) in a human HER2-expressing syngeneic breast cancer model resistant to trastuzumab and ado-trastuzumab emtansine. Mechanistically, the anthracycline component of the novel ADC induced immunogenic cell death leading to exposure and secretion of danger-associated molecular signals. RNA sequencing derived immunogenomic signatures and TCRß clonotype analysis of tumor-infiltrating lymphocytes revealed a prominent role of the adaptive immune system in the regulation of T-PNU mediated anti-cancer activity. Depletion of CD8 T cells severely reduced T-PNU efficacy, thus confirming the role of cytotoxic T cells as drivers of the T-PNU mediated anti-tumor immune response. Furthermore, T-PNU therapy promoted immunological memory formation in tumor-bearing animals protecting those from tumor rechallenge. Finally, the combination of T-PNU and checkpoint inhibition, such as α-PD1, significantly enhanced tumor eradication following the treatment. In summary, a novel PNU-armed, HER2-targeting ADC elicited long-lasting immune protection in a murine orthotopic breast cancer model resistant to other HER2-directed therapies. Our findings delineate the therapeutic potential of this novel ADC payload and support its clinical development for breast cancer patients and potentially other HER2 expressing malignancies.

Correction: A molecular portrait of epithelial-mesenchymal plasticity in prostate cancer associated with clinical outcome.

Following the publication of the above article, the authors noted an error in Figure 4, panel B. The colours of the localized and mCRPC samples were accidentally switched. The authors have corrected the colour scheme and added a key to the figure. They have also updated the colour scheme of panel C, both bars are now red instead of one red and one blue. The authors wish to apologize for any inconvenience caused.