BM-derived DC (BMDC) are powerful antigen-presenting cells. When loaded with immune complexes (IC), consisting of tumor antigens bound to antitumor antibody, BMDC induce powerful antitumor immunity in mice. However, attempts to employ this strategy clinically with either tumor-associated DC (TADC) or monocyte-derived DC (MoDC) have been disappointing. To investigate the basis for this phenomenon, we compared the response of BMDC, TADC, and MoDC to tumor IgG-IC. Our findings revealed, in both mice and humans, that upon exposure to IgG-IC, BMDC internalized the IC, increased costimulatory molecule expression, and stimulated autologous T cells. In contrast, TADC and, surprisingly, MoDC remained inert upon contact with IC due to dysfunctional signaling following engagement of Fcγ receptors. Such dysfunction is associated with elevated levels of the Src homology region 2 domain–containing phosphatase-1 (SHP-1) and phosphatases regulating Akt activation. Indeed, concomitant inhibition of both SHP-1 and phosphatases that regulate Akt activation conferred upon TADC and MoDC the capacity to take up and process IC and induce antitumor immunity in vivo. This work identifies the molecular checkpoints that govern activation of MoDC and TADC and their capacity to elicit T cell immunity.
Yaron Carmi, Tyler R. Prestwood, Matthew H. Spitzer, Ian L. Linde, Jonathan Chabon, Nathan E. Reticker-Flynn, Nupur Bhattacharya, Hong Zhang, Xiangyue Zhang, Pamela A. Basto, Bryan M. Burt, Michael N. Alonso, Edgar G. Engleman
To identify the molecules involved in epithelial to mesenchymal transition (EMT) in urothelial carcinoma (UC) after acquisition of platinum resistance, here we examined the changes in global gene expression before and after platinum treatment. Four invasive UC cell lines, T24, 5637, and their corresponding sublines T24PR and 5637PR with acquired platinum resistance, were assessed by microarray, and the ubiquitin E3 ligase FBXO32 was newly identified as a negative regulator of EMT in UC tumors after acquisition of platinum resistance. In vitro and in vivo studies showed an intimate relationship between FBXO32 expression and EMT, demonstrating that FBXO32 dysregulation in T24PR cells results in elevated expression of the mesenchymal molecules SNAIL and vimentin and decreased expression of the epithelial molecule E-cadherin. The association between FBXO32 expression and EMT was further validated using clinical samples. Knockdown of MyoD expression, a specific target of FBXO32 polyubiquitination, revealed upregulation of E-cadherin expression and downregulation of SNAIL and vimentin expression in T24PR cells. Comparative genomic hybridization array analysis demonstrated loss of heterozygosity at 8q24.13 in T24PR cells, which harbors FBXO32. Our findings suggest the importance of the association between EMT and ubiquitin-proteasome regulation when tumors develop acquired platinum resistance.
Nobuyuki Tanaka, Takeo Kosaka, Yasumasa Miyazaki, Shuji Mikami, Naoya Niwa, Yutaro Otsuka, Yoji Andrew Minamishima, Ryuichi Mizuno, Eiji Kikuchi, Akira Miyajima, Hisataka Sabe, Yasunori Okada, Per Uhlén, Makoto Suematsu, Mototsugu Oya
Current antiangiogenesis therapy relies on inhibiting newly developed immature tumor blood vessels and starving tumor cells. This strategy has shown transient and modest efficacy. Here, we report a better approach to target cancer-associated endothelial cells (ECs), reverse permeability and leakiness of tumor blood vessels, and improve delivery of chemotherapeutic agents to the tumor. First, we identified deregulated microRNAs (miRs) from patient-derived cancer-associated ECs. Silencing these miRs led to decreased vascular permeability and increased maturation of blood vessels. Next, we screened a thioaptamer (TA) library to identify TAs selective for tumor-associated ECs. An annexin A2–targeted TA was identified and used for delivery of miR106b-5p and miR30c-5p inhibitors, resulting in vascular maturation and antitumor effects without inducing hypoxia. These findings could have implications for improving vascular-targeted therapy.
Lingegowda S. Mangala, Hongyu Wang, Dahai Jiang, Sherry Y. Wu, Anoma Somasunderam, David E. Volk, Ganesh L. R. Lokesh, Xin Li, Sunila Pradeep, Xianbin Yang, Monika Haemmerle, Cristian Rodriguez-Aguayo, Archana S Nagaraja, Rajesha Rupaimoole, Emine Bayraktar, Recep Bayraktar, Li Li, Takemi Tanaka, Wei Hu, Cristina Ivan, Kshipra M Gharpure, Michael H. McGuire, Varatharasa Thiviyanathan, Xinna Zhang, Sourindra N. Maiti, Nataliya Bulayeva, Hyun-Jin Choi, Piotr L. Dorniak, Laurence J.N. Cooper, Kevin P. Rosenblatt, Gabriel Lopez-Berestein, David G. Gorenstein, Anil K. Sood
Recent clinical trials have demonstrated a clear survival advantage in advanced head and neck squamous cell carcinoma (HNSCC) patients treated with immune checkpoint blockade. These emerging results reveal that HNSCC is one of the most promising frontiers for immunotherapy research. However, further progress in head and neck immuno-oncology will require a detailed understanding of the immune infiltrative landscape found in these tumors. We leveraged transcriptome data from 280 tumors profiled by The Cancer Genome Atlas (TCGA) to comprehensively characterize the immune landscape of HNSCC in order to develop a rationale for immunotherapeutic strategies in HNSCC and guide clinical investigation. We find that both HPV+ and HPV– HNSCC tumors are among the most highly immune-infiltrated cancer types. Strikingly, HNSCC had the highest median Treg/CD8+ T cell ratio and the highest levels of CD56dim NK cell infiltration, in our pan-cancer analysis of the most immune-infiltrated tumors. CD8+ T cell infiltration and CD56dim NK cell infiltration each correlated with superior survival in HNSCC. Tumors harboring genetic smoking signatures had lower immune infiltration and were associated with poorer survival, suggesting these patients may benefit from immune agonist therapy. These findings illuminate the immune landscape of HPV+ and HPV– HNSCC. Additionally, this landscape provides a potentially novel rationale for investigation of agents targeting modulators of Tregs (e.g., CTLA-4, GITR, ICOS, IDO, and VEGFA) and NK cells (e.g., KIR, TIGIT, and 4-1BB) as adjuncts to anti–PD-1 in the treatment of advanced HNSCC.
Rajarsi Mandal, Yasin Şenbabaoğlu, Alexis Desrichard, Jonathan J. Havel, Martin G. Dalin, Nadeem Riaz, Ken-Wing Lee, Ian Ganly, A. Ari Hakimi, Timothy A. Chan, Luc G.T. Morris
Esophageal squamous cell carcinoma (ESCC) is endemic in regions of sub-Saharan Africa (SSA), where it is the third most common cancer. Here, we describe whole-exome tumor/normal sequencing and RNA transcriptomic analysis of 59 patients with ESCC in Malawi. We observed similar genetic aberrations as reported in Asian and North American cohorts, including mutations of
Wenjin Liu, Jeff M. Snell, William R. Jeck, Katherine A. Hoadley, Matthew D. Wilkerson, Joel S. Parker, Nirali Patel, Yohannie B. Mlombe, Gift Mulima, N. George Liomba, Lindsey L. Wolf, Carol G. Shores, Satish Gopal, Norman E. Sharpless
Aberrant wnt/β-catenin signaling and amplification/overexpression of Myc are associated with hepatoblastoma (HB), the most prevalent type of childhood liver cancer. To address their roles in the pathogenesis of HB, we generated mice in which Myc and mutant β-catenin were targeted to immature cells of the developing mouse liver. Perinatal coexpression of both genes promoted the preferential development of HBs over other tumor types in neonatal mice, all of which bore striking resemblance to their human counterparts. Integrated analysis indicated that tumors emerged as a consequence of Myc-driven alterations in hepatoblast fate in a background of pan-hepatic injury, inflammation, and nuclear factor (erythroid-derived 2)-like 2/Nrf2-dependent antioxidant signaling, which was specifically associated with expression of mutant β-catenin but not Myc. Immunoprofiling of human HBs confirmed that approximately 50% of tumors demonstrated aberrant activation of either Myc or Nfe2l2/Nrf2, while knockdown of Nrf2 in a cell line–derived from a human HB with
Sarah A. Comerford, Elizabeth A. Hinnant, Yidong Chen, Hima Bansal, Shawn Klapproth, Dinesh Rakheja, Milton J. Finegold, Dolores Lopez-Terrada, Kathryn A. O’Donnell, Gail E. Tomlinson, Robert E. Hammer
In carcinogen-driven cancers, a high mutational burden results in neoepitopes that can be recognized immunologically. Such carcinogen-induced tumors may evade this immune response through “immunoediting,” whereby tumors adapt to immune pressure and escape T cell–mediated killing. Many tumors lack a high neoepitope burden, and it remains unclear whether immunoediting occurs in such cases. Here, we evaluated T cell immunity in an autochthonous mouse model of pancreatic cancer and found a low mutational burden, absence of predicted neoepitopes derived from tumor mutations, and resistance to checkpoint immunotherapy. Spontaneous tumor progression was identical in the presence or absence of T cells. Moreover, tumors arising in T cell–depleted mice grew unchecked in immune-competent hosts. However, introduction of the neoantigen ovalbumin (OVA) led to tumor rejection and T cell memory, but this did not occur in OVA immune-tolerant mice. Thus, immunoediting does not occur in this mouse model — a likely consequence, not a cause, of absent neoepitopes. Because many human tumors also have a low missense mutational load and minimal neoepitope burden, our findings have clinical implications for the design of immunotherapy for patients with such tumors.
Rebecca A. Evans, Mark S. Diamond, Andrew J. Rech, Timothy Chao, Max W. Richardson, Jeffrey H. Lin, David L. Bajor, Katelyn T. Byrne, Ben Z. Stanger, James L. Riley, Nune Markosyan, Rafael Winograd, Robert H. Vonderheide
Metastatic dissemination of cancer cells, which accounts for 90% of cancer mortality, is the ultimate hallmark of malignancy. Growing evidence suggests that blood platelets have a predominant role in tumor metastasis; however, the molecular mechanisms involved remain elusive. Here, we demonstrate that genetic deficiency of integrin α6β1 on platelets markedly decreases experimental and spontaneous lung metastasis. In vitro and in vivo assays reveal that human and mouse platelet α6β1 supports platelet adhesion to various types of cancer cells. Using a knockdown approach, we identified ADAM9 as the major counter receptor of α6β1 on both human and mouse tumor cells. Static and flow-based adhesion assays of platelets binding to DC-9, a recombinant protein covering the disintegrin-cysteine domain of ADAM9, demonstrated that this receptor directly binds to platelet α6β1. In vivo studies showed that the interplay between platelet α6β1 and tumor cell–expressed ADAM9 promotes efficient lung metastasis. The integrin α6β1–dependent platelet-tumor cell interaction induces platelet activation and favors the extravasation process of tumor cells. Finally, we demonstrate that a pharmacological approach targeting α6β1 efficiently impairs tumor metastasis through a platelet-dependent mechanism. Our study reveals a mechanism by which platelets promote tumor metastasis and suggests that integrin α6β1 represents a promising target for antimetastatic therapies.
Elmina Mammadova-Bach, Paola Zigrino, Camille Brucker, Catherine Bourdon, Monique Freund, Adèle De Arcangelis, Scott I. Abrams, Gertaud Orend, Christian Gachet, Pierre Henri Mangin
Regulation of lineage-restricted transcription factors has been shown to influence malignant transformation in several types of cancer. Whether similar mechanisms are involved in ovarian cancer pathogenesis is unknown. PAX8 is a nuclear transcription factor that controls the embryologic development of the Müllerian system, including the fallopian tubes. Recent studies have shown that fallopian tube secretory epithelial cells (FTSECs) give rise to the most common form of ovarian cancer, high-grade serous ovarian carcinomas (HGSOCs). We designed the present study in order to understand whether changes in gene expression between FTSECs and HGSOCs relate to alterations in PAX8 binding to chromatin. Using whole transcriptome shotgun sequencing (RNA-Seq) after PAX8 knockdown and ChIP-Seq, we show that FTSECs and HGSOCs are distinguished by marked reprogramming of the PAX8 cistrome. Genes that are significantly altered between FTSECs and HGSOCs are enriched near PAX8 binding sites. These sites are also near TEAD binding sites, and these transcriptional changes may be related to PAX8 interactions with the TEAD/YAP1 signaling pathway. These data suggest that transcriptional changes after transformation in ovarian cancer are closely related to epigenetic remodeling in lineage-specific transcription factors.
Kevin M. Elias, Megan M. Emori, Thomas Westerling, Henry Long, Anna Budina-Kolomets, Fugen Li, Emily MacDuffie, Michelle R. Davis, Alexander Holman, Brian Lawney, Matthew L. Freedman, John Quackenbush, Myles Brown, Ronny Drapkin
Constitutively active splice variants of androgen receptor (AR-Vs) lacking ligand-binding domain (LBD) are a mechanism of resistance to androgen receptor LBD–targeted (AR LBD–targeted) therapies for metastatic castration-resistant prostate cancer (CRPC). There is a strong unmet clinical need to identify prostate cancer patients with AR-V–positive lesions to determine whether they will benefit from further AR LBD–targeting therapies or should receive taxanes or investigational drugs like EPI-506 or galeterone. Both EPI-506 (NCT02606123) and galeterone (NCT02438007) are in clinical trials and are proposed to have efficacy against lesions that are positive for AR-Vs. AR activation function-1 (AF-1) is common to the N-terminal domains of full-length AR and AR-Vs. Here, we provide proof of concept for developing imaging compounds that directly bind AR AF-1 to detect both AR-Vs and full-length AR. 123I-EPI-002 had specific binding to AR AF-1, which enabled direct visualization of CRPC xenografts that express full-length AR and AR-Vs. Our findings highlight the potential of 123I-EPI-002 as an imaging agent for the detection of full-length AR and AR-Vs in CRPC.
Yusuke Imamura, Amy H. Tien, Jinhe Pan, Jacky K. Leung, Carmen A. Banuelos, Kunzhong Jian, Jun Wang, Nasrin R. Mawji, Javier Garcia Fernandez, Kuo-Shyan Lin, Raymond J. Andersen, Marianne D. Sadar
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