Purpose: Therapeutic blockade of immune checkpoints has revolutionized cancer treatment. Durable responses, however, occur in less than half of those treated, and efforts to improve treatment efficacy are confounded by a lack of understanding of the characteristics of the cells that initiate antitumor immune response. Patients and Methods: We performed multiparameter flow cytometry and quantitative multiplex immunofluorescence staining on tumor specimens from immunotherapy-naïve melanoma patients and longitudinal biopsy specimen obtained from patients undergoing anti–PD-1 therapy. Results: Increased numbers of CD69+CD103+ tumor-resident CD8+ T cells were associated with improved melanoma-specific survival in immunotherapy-naïve melanoma patients. Local IL15 expression levels strongly correlated with these tumor-resident T-cell numbers. The expression of several immune checkpoints including PD-1 and LAG3 was highly enriched in this subset, and these cells significantly expanded early during anti–PD-1 immunotherapy. Conclusions: Tumor-resident CD8+ T-cell numbers are more prognostic than total CD8+ T cells in metastatic melanoma. In addition, they are likely to initiate response to anti–PD-1 and anti–LAG-3 treatments. We propose that the immune profile of these cells prior to treatment could inform strategies for immune checkpoint blockade. Clin Cancer Res; 24(13); 3036–45. ©2018 AACR.

Re is emerging. While TACE improves survival in selected patients, the resulting tumor hypoxia stimulates proliferation, angiogenesis, treatment resistance and metastasis, which limits its overall efficacy. Vessel normalization decreases hypoxia and improves anti-tumor immune infiltrate and drug delivery. Several pre-clinical agents aimed at normalizing tumor vasculature in HCC appear promising. Although anti-angiogenic agents with vessel normalizing potential have been trialed in advanced HCC with modest results, to date their primary intention had been to starve the tumor. Judicious use of anti-angiogenic therapies is required to achieve vessel normalization yet avoid excessive pruning of vessels. This balance, termed the normalization window, is yet uncharacterized in HCC. However, the optimal class, dose and schedule of vascular normalization agents, alone or in combination with other therapies needs to be explored further....

Lipotoxic stress‐induced β‐cell death (lipotoxicity) is recognized as a key contributor to the development of type 2 diabetes mellitus (T2DM). The current study reports a critical role of sphingosine kinase 1 (SphK1) in β‐cell survival under lipotoxic conditions. In an attempt to investigate the role of SphK1 in lipotoxicity in vivo, we fed Sphk1 ^–/– and wild‐type (WT) mice with a high‐fat diet (HFD) or normal chow diet. Remarkably, while HFD‐fed WT mice developed glucose intolerance and compensatory hyperinsulinemia, all HFD‐fed Sphk1 ^–/– mice manifested evident diabetes, accompanied by a nearly 3‐fold reduction in insulin levels compared with the WT mice. Pancreatic β‐cell mass was increased by 140% in HFD‐fed WT mice but decreased to 50% in HFD‐fed Sphk1 ^–/– mice, in comparison with the chow diet control groups, respectively. Accordingly, by blocking the enzyme activity, expression of a dominant negative form of SphK1 markedly promoted palmitate‐induced cell death in MIN6 and INS‐1 β‐cell lines. Moreover, primary islets isolated from Sphk1 ^–/– mice exhibited higher susceptibility to lipotoxicity than WT controls. Of note, sphingosine 1‐phosphate (S1P) profoundly abrogated lipotoxicity in β cells or the cells lacking SphK1 activity and Sphk1 ^–/– islets, highlighting a pivotal role of S1P in β‐cell survival under lipotoxic conditions. These findings could suggest a new therapeutic strategy for preventing β‐cell death and thus the onset of T2DM.—Qi, Y., Chen, J., Lay, A., Don, A., Vadas, M., Xia, P., Loss of sphingosine kinase 1 predisposes to the onset of diabetes via promoting pancreatic β‐cell death in diet‐induced obese mice. FASEB J. 27, 4294–4304 (2013). www.fasebj.org

Objective— The transcription factor early growth response (EGR)-1 has been implicated as a key vascular phenotypic switch through its control of inducible transcription. EGR-1 autoregulation, and histone modification in the EGR-1 promoter, represent key mechanisms in EGR-1 control, but have not been explored. Methods and Results— We demonstrate that EGR-1 regulates its own transcription and that this involves histone H3 phosphorylation and acetylation. EGR-1 transactivates its promoter in smooth muscle cells exposed to interleukin (IL) 1β through a novel cis -acting element (−211/−203). PD98059, which inhibits mitogen-activated protein kinase kinase/extracellular regulated kinase (MEK/ERK) attenuates IL-1β–inducible phosphorylation of extracellular signal–regulated kinase 1/2 and mitogen and stress–activated protein kinases 1/2; and reduces levels of phosphorylated and acetylated histone H3. Histone deacetylase inhibition enhances EGR-1 transcription in response to cytokine. Conversely, suppression of histone modification with mitogen and stress–activated protein kinase 1/2 short interfering RNA, or the histone H3 acetyltransferase inhibitor Garcinol, inhibits IL-1β–inducible EGR-1 transcription. EGR-1 interacts with the acetyltransferase p300. Acetylated H3 and phosphorylated H3 are enriched at the promoter of EGR-1; and EGR-1 is enriched at the promoters of tissue factor and plasminogen activator inhibitor 1 in response to IL-1β, and attenuated by PD98059, Garcinol, and mitogen and stress–activated protein kinase 1/2 short interfering RNA. Conclusion— IL-1β induction of EGR-1 transcription involves histone H3 phosphorylation, acetylation, and autoregulation by EGR-1.

Embryonal cancer can arise from postnatally persistent embryonal remnant or rest cells, which are uniquely characterized by the absence of p53 mutations. Perinatal overexpression of the MycN oncoprotein in embryonal cancer precursor cells causes postnatal rests, and later tumor formation through unknown mechanisms. However, overexpression of Myc in adult tissues normally activates apoptosis and/or senescence signals as an organismal defense mechanism against cancer. Here, we show that perinatal neuroblastoma precursor cells exhibited a transiently diminished p53 response to MycN oncoprotein stress and resistance to trophic factor withdrawal, compared with their adult counterpart cells from the TH-MYCN^+/+ transgenic mouse model of neuroblastoma. The adult stem cell maintenance factor and Polycomb group protein, Bmi1 (B-cell-specific Moloney murine leukemia virus integration site), had a critical role at neuroblastoma initiation in the model, by repressing p53 responses in precursor cells. We further show in neuroblastoma tumor cells that Bmi1 could directly bind p53 in a complex with other Polycomb complex proteins, Ring1A or Ring1B, leading to increased p53 ubiquitination and degradation. Repressed p53 signal responses were also seen in precursor cells for other embryonal cancer types, medulloblastoma and acute lymphoblastic leukemia. Collectively, these date indicate a general mechanism for p53 inactivation in some embryonal cell types and consequent susceptibility to MycN oncogenesis at the point of embryonal tumor initiation.

T-cell infiltration of solid tumors is associated with improved prognosis and favorable responses to immunotherapy. Mechanisms that enable tumor infiltration of CD8⁺ T cells have not been defined, nor have drugs that assist this process been discovered. Here we address these issues with a focus on VE-cadherin, a major endothelial cell–specific junctional protein that controls vascular integrity. A decrease in VE-cadherin expression is associated with tumor pathology. We developed an oligonucleotide-based inhibitor (CD5-2), which disrupted the interaction of VE-cadherin with its regulator miR-27a, resulting in increased VE-cadherin expression. Administration of CD5-2 in tumor-bearing mice enhanced expression of VE-cadherin in tumor endothelium, activating TIE-2 and tight junction pathways and normalizing vessel structure and function. CD5-2 administration also enhanced tumor-specific T-cell infiltration and spatially redistributed CD8⁺ T cells within the tumor parenchyma. Finally, CD5-2 treatment enhanced the efficacy of anti-PD-1 blocking antibody. Our work establishes a role for VE-cadherin in T-cell infiltration in tumors and offers a preclinical proof of concept for CD5-2 as a therapeutic modifier of cancer immunotherapy via effects on the tumor vasculature. Cancer Res; 77(16); 4434–47. ©2017 AACR.