Wan, L;Lin, KT;Rahman, MA;Ishigami, Y;Wang, Z;Jensen, MA;Wilkinson, JE;Park, Y;Tuveson, DA;Krainer, AR;
PMID: 37098965 | DOI: 10.1158/2159-8290.CD-22-1013
Inflammation is strongly associated with pancreatic ductal adenocarcinoma (PDAC), a highly lethal malignancy. Dysregulated RNA splicing factors have been widely reported in tumorigenesis, but their involvement in pancreatitis and PDAC is not well understood. Here, we report that the splicing factor SRSF1 is highly expressed in pancreatitis, PDAC precursor lesions, and tumors. Increased SRSF1 is sufficient to induce pancreatitis and accelerate KRASG12D-mediated PDAC. Mechanistically, SRSF1 activates MAPK signaling-partly by upregulating interleukin 1 receptor type 1 (IL1R1) through alternative-splicing-regulated mRNA stability. Additionally, SRSF1 protein is destabilized through a negative feedback mechanism in phenotypically normal epithelial cells expressing KRASG12D in mouse pancreas, and in pancreas organoids acutely expressing KRASG12D, buffering MAPK signaling and maintaining pancreas-cell homeostasis. This negative-feedback regulation of SRSF1 is overcome by hyperactive MYC, facilitating PDAC tumorigenesis. Our findings implicate SRSF1 in the etiology of pancreatitis and PDAC, and point to SRSF1-misregulated alternative splicing as a potential therapeutic target.
Life (Basel, Switzerland)
Ross, AM;Leahy, CI;Neylon, F;Steigerova, J;Flodr, P;Navratilova, M;Urbankova, H;Vrzalikova, K;Mundo, L;Lazzi, S;Leoncini, L;Pugh, M;Murray, PG;
PMID: 36836878 | DOI: 10.3390/life13020521
Epstein-Barr virus (EBV), defined as a group I carcinogen by the World Health Organization (WHO), is present in the tumour cells of patients with different forms of B-cell lymphoma, including Burkitt lymphoma, Hodgkin lymphoma, post-transplant lymphoproliferative disorders, and, most recently, diffuse large B-cell lymphoma (DLBCL). Understanding how EBV contributes to the development of these different types of B-cell lymphoma has not only provided fundamental insights into the underlying mechanisms of viral oncogenesis, but has also highlighted potential new therapeutic opportunities. In this review, we describe the effects of EBV infection in normal B-cells and we address the germinal centre model of infection and how this can lead to lymphoma in some instances. We then explore the recent reclassification of EBV+ DLBCL as an established entity in the WHO fifth edition and ICC 2022 classifications, emphasising the unique nature of this entity. To that end, we also explore the unique genetic background of this entity and briefly discuss the potential role of the tumour microenvironment in lymphomagenesis and disease progression. Despite the recent progress in elucidating the mechanisms of this malignancy, much work remains to be done to improve patient stratification, treatment strategies, and outcomes.
Pitter, KL;Grbovic-Huezo, O;Joost, S;Singhal, A;Blum, M;Wu, K;Holm, M;Ferrena, A;Bhutkar, A;Hudson, A;Lecomte, N;de Stanchina, E;Chaligne, R;Iacobuzio-Donahue, CA;Pe'er, D;Tammela, T;
PMID: 35952360 | DOI: 10.1158/0008-5472.CAN-22-1742
Intra-tumoral heterogeneity and cellular plasticity have emerged as hallmarks of cancer, including pancreatic ductal adenocarcinoma (PDAC). As PDAC portends a dire prognosis, a better understanding of the mechanisms underpinning cellular diversity in PDAC is crucial. Here, we investigated the cellular heterogeneity of PDAC cancer cells across a range of in vitro and in vivo growth conditions using single-cell genomics. Heterogeneity contracted significantly in 2D and 3D cell culture models but was restored upon orthotopic transplantation. Orthotopic transplants reproducibly acquired cell states identified in autochthonous PDAC tumors, including a basal state exhibiting co-expression and co-accessibility of epithelial and mesenchymal genes. Lineage-tracing combined with single-cell transcriptomics revealed that basal cells display high plasticity in situ. This work defines the impact of cellular growth conditions on phenotypic diversity and uncovers a highly plastic cell state with the capacity to facilitate state transitions and promote intra-tumoral heterogeneity in PDAC.
Zhang, JY;Du, Y;Gong, LP;Shao, YT;Pan, LJ;Feng, ZY;Pan, YH;Huang, JT;Wen, JY;Sun, LP;Chen, GF;Chen, JN;Shao, CK;
PMID: 35304258 | DOI: 10.1016/j.canlet.2022.215646
Epstein-Barr virus (EBV) is a tumor virus that is associated with a variety of neoplasms, including EBV-associated gastric carcinoma (EBVaGC). Recently, EBV was reported to generate various circular RNAs (circRNAs). CircRNAs are important regulators of tumorigenesis by modulating the malignant behaviors of tumor cells. However, to date, the functions of ebv-circRNAs in EBVaGC remain poorly understood. In the present study, we observed high ebv-circRPMS1 expression in EBVaGC and showed that ebv-circRPMS1 promoted the proliferation, migration, and invasion and inhibited the apoptosis of EBVaGC cells. In addition, METTL3 was upregulated in GC cells overexpressing ebv-circRPMS1. Mechanistically, ebv-circRPMS1 bound to Sam68 to facilitate its physical interaction with the METTL3 promotor, resulting in the transactivation of METTL3 and cancer progression. In clinical EBVaGC samples, ebv-circRPMS1 was associated with distant metastasis and a poor prognosis. Based on these findings, ebv-circRPMS1 contributed to EBVaGC progression by recruiting Sam68 to the METTL3 promoter to induce METTL3 expression. ebv-circRPMS1, Sam68, and METTL3 might serve as therapeutic targets for EBVaGC.
Journal of cancer research and clinical oncology
Bakker, A;Slack, JC;Palanisamy, N;Carskadon, S;Ghosh, S;Khalifeh, I;Bismar, TA;
PMID: 35982181 | DOI: 10.1007/s00432-022-04279-5
KLK4::KLKP1 fusion is a recently described pseudogene that is enriched in prostate cancer (PCa). This new biomarker has not been characterized in the Middle Eastern population.To establish the incidence and prognostic value of KLK4::KLKP1 fusion in a cohort of Middle Eastern men with PCa and explore the relationship of this marker to other relevant biomarkers (PTEN, ERG, SPINK1).We interrogated a cohort of 340 Middle Eastern men with localized PCa treated by radical prostatectomy between 2005 and 2015. KLK4::KLKP1 fusion status was assessed by RNA Chromogenic in situ hybridization (CISH) and correlated to pathological and clinical parameters.RNA-CISH expression of KLK4::KLKP1 was correlated with prognostic factors, ERG, PTEN, and SPINK1 expression, and biochemical recurrence (BCR) following prostatectomy.51.7% of patient samples showed positive KLK4::KLKP1 expression; more commonly in cores of PCa (38%) versus non-cancer (20.6%) (p < 0.0001) and in lower Gleason Grade Group tumors (1-3) vs (4-5). KLK4::KLKP1 expression positively correlated with ERG positivity and inversely associated with PTEN loss. No significant association was found with SPINK1 expression, seminal vesicle invasion, positive surgical margin, pathological stage, or patient age (< 50 or ≥ 50). The association between PTEN loss and BCR increased when combined with KLK4::KLKP1 negativity (HR 2.31, CI 1.03-5.20, p = 0.042).KLK4::KLKP1 expression is more common in this cohort of Middle Eastern men than has been reported in North American men. It is associated with ERG positivity and inversely correlated with PTEN loss. In isolation, KLK4::KLKP1 expression was not significantly associated with clinical outcome or pathological parameters. However, its expression is associated with certain molecular subtypes (ERG-positive, PTEN-intact) and as we demonstrate may help further stratify the risk of recurrence within these groups.
Immune analysis of lymph nodes in relation to the presence or absence of tumor infiltrating lymphocytes in triple-negative breast cancer
European journal of cancer (Oxford, England : 1990)
Quintana, Á;Peg, V;Prat, A;Moliné, T;Villacampa, G;Paré, L;Galván, P;Dientsmann, R;Schmid, P;Curigliano, G;Muñoz-Couselo, E;Perez-García, J;Marti, M;Blanco-Heredia, J;Anjos, CD;Vazquez, M;De Mattos-Arruda, L;Cortés, J;
PMID: 33743482 | DOI: 10.1016/j.ejca.2021.01.037
Triple-negative breast cancer (TNBC) is a subtype of breast cancer with unmet medical needs. Several studies have proved that high levels of tumor infiltrating lymphocytes (TILs) at diagnosis of TNBC confer better prognosis and patients respond better to specific chemotherapies. Nonetheless, current evidence suggests that only 15% of TNBC patients have very high levels of TILs, and another 15% lacks TILs. One possible reason to explain why patients have low TILs at diagnosis is that lymphocytes might be deactivated by an immune checkpoint in local lymph nodes, provoking their retention in there as they are unresponsive to other immune stimuli. We have identified 15 high TILs (≥50%) and 20 low TILs (≤5%) TNBC patients with localised tumour (T1c-T2N0M0) and compared the protein expression of five immune checkpoints in lymph nodes. We have also performed a customised 50-immune gene NanoString expression panel, the NanoString 360 Breast Cancer panel, and whole exome sequencing for mutation and neoantigen load analyses. In low TILs, we observed higher expression of CTLA-4 in local lymph nodes, which could explain why lymphocytes get retained in there and do not migrate to tumour. These patients have also higher neoantigen load and higher expression of B7.H3 and B7.H4 in the tumour. In high TILs, we observed more PD-L1+ tumour cells and more expanded humoral response. These results could provide a strategy to revert low tumour immune infiltration at diagnosis of TNBC, improving their prognosis.
Zhu, Y;Moore, S;Wang, A;George, E;Allard, GM;Libert, DM;Lowe, AC;
PMID: 37069606 | DOI: 10.1002/cncy.22706
Epithelial cell adhesion molecule (EpCAM) is frequently used to distinguish carcinoma from background mesothelial cells during cytologic examination of body cavity fluids. Previously, the authors identified one malignant mesothelioma case with strong and diffuse membranous EpCAM staining, making it indistinguishable from carcinoma.In this study, the authors evaluated all available effusion specimens from patients with malignant mesothelioma, including the above-mentioned index case, obtained at Stanford Health Care, from 2011 to 2021 (N = 17) as well as control cases (N = 5). Analyses included an immunohistochemistry (IHC) assay for EpCAM and claudin-4, a multiplexed immunofluorescent (IF) assay for EpCAM, and an RNA in situ hybridization assay targeting EpCAM.The authors detected EpCAM positivity of variable intensity and percentage in four malignant mesothelioma cases (23.5%; although only two showed positivity for the epithelial-specific IHC marker MOC31 in ≥40% of cells) and claudin-4 negativity in all cases, with two cases displaying focal and weak claudin-4 staining in <1% of cells. Multiplexed IF staining on the cases with EpCAM IHC positivity showed strong, membranous EpCAM staining in one of four cases. RNA in situ hybridization also was used to assess the correlation between EpCAM positivity by IHC/IF and RNA expression levels. Strong EpCAM RNA expression was detected in the three malignant mesothelioma cases.The current findings revealed that a subset of epithelioid malignant mesothelioma cases mimic or exhibit the immunophenotypic features of carcinoma when evaluating for EpCAM only. Additional biomarker testing, such as claudin-4, may help avoid this potential pitfall to yield accurate diagnoses.
Elhanani, O;Ben-Uri, R;Keren, L;
PMID: 36800999 | DOI: 10.1016/j.ccell.2023.01.010
The tumor microenvironment (TME) is composed of many different cellular and acellular components that together drive tumor growth, invasion, metastasis, and response to therapies. Increasing realization of the significance of the TME in cancer biology has shifted cancer research from a cancer-centric model to one that considers the TME as a whole. Recent technological advancements in spatial profiling methodologies provide a systematic view and illuminate the physical localization of the components of the TME. In this review, we provide an overview of major spatial profiling technologies. We present the types of information that can be extracted from these data and describe their applications, findings and challenges in cancer research. Finally, we provide a future perspective of how spatial profiling could be integrated into cancer research to improve patient diagnosis, prognosis, stratification to treatment and development of novel therapeutics.
Flores-Téllez, TDNJ;Baena, E;
PMID: 34688843 | DOI: 10.1016/j.canlet.2021.10.012
Tumor heterogeneity plays a key role in prostate cancer prognosis, therapy selection, relapse, and acquisition of treatment resistance. Prostate cancer presents a heterogeneous diversity at inter- and intra-tumor and inter-patient levels which are influenced by multiple intrinsic and/or extrinsic factors. Recent studies have started to characterize the complexity of prostate tumors and these different tiers of heterogeneity. In this review, we discuss the most common factors that contribute to tumoral diversity. Moreover, we focus on the description of the in vitro and in vivo approaches, as well as high-throughput technologies, that help to model intra-tumoral diversity. Further understanding tumor heterogeneities and the challenges they present will guide enhanced patient risk stratification, aid the design of more precise therapies, and ultimately help beat this chameleon-like disease.
Mohan, DR;Borges, KS;Finco, I;LaPensee, CR;Rege, J;Solon, AL;Little, DW;Else, T;Almeida, MQ;Dang, D;Haggerty-Skeans, J;Apfelbaum, AA;Vinco, M;Wakamatsu, A;Mariani, BMP;Amorim, LC;Latronico, AC;Mendonca, BB;Zerbini, MCN;Lawlor, ER;Ohi, R;Auchus, RJ;Rainey, WE;Marie, SKN;Giordano, TJ;Venneti, S;Fragoso, MCBV;Breault, DT;Lerario, AM;Hammer, GD;
PMID: 37129912 | DOI: 10.1158/0008-5472.CAN-22-2712
Adrenocortical carcinoma (ACC) is a rare cancer in which tissue-specific differentiation is paradoxically associated with dismal outcomes. The differentiated ACC subtype CIMP-high is prevalent, incurable, and routinely fatal. CIMP-high ACC possess abnormal DNA methylation and frequent β-catenin activating mutations. Here, we demonstrated that ACC differentiation is maintained by a balance between nuclear, tissue-specific β-catenin-containing complexes and the epigenome. On chromatin, β-catenin bound master adrenal transcription factor SF1 and hijacked the adrenocortical super-enhancer landscape to maintain differentiation in CIMP-high ACC; off chromatin, β-catenin bound histone methyltransferase EZH2. SF1/β-catenin and EZH2/β-catenin complexes present in normal adrenals persisted through all phases of ACC evolution. Pharmacologic EZH2 inhibition in CIMP-high ACC expelled SF1/β-catenin from chromatin and favored EZH2/β-catenin assembly, erasing differentiation and restraining cancer growth in vitro and in vivo. These studies illustrate how tissue-specific programs shape oncogene selection, surreptitiously encoding targetable therapeutic vulnerabilities.
Klempner, S;Chao, J;Uronis, H;Sirard, C;Kagey, M;Baum, J;Song, J;Wang, J;Sonbol, M;Wainberg, Z;Ajani, J;
| DOI: 10.1016/j.annonc.2022.07.1331
Background Despite recent approval of anti-PD-1 antibodies as 1L therapy in advanced GEA, benefit is largely limited to PD-L1 combined positive scores (CPS) ≥5 patients (pts); novel therapeutic approaches are needed. DKN-01 is a targeted anti-DKK1 mAb which has demonstrated activity in GEA pts with elevated tumoral DKK1 expression, a subset of pts with more aggressive disease and shorter overall survival. Methods Phase IIa single arm trial investigating DKN-01 300 mg (D) + tislelizumab (TS) + CAPOX as 1L therapy in advanced HER2(-) GEA regardless of DKK1 status. Tumoral DKK1 mRNA expression was assessed by a chromogenic in situ hybridization RNAscope assay and assigned an H-score (0-300). Primary endpoint was ORR in modified intent to treat (mITT) population (>1 dose D); secondary endpoints included PFS and OS in intent to treat (ITT) population overall and by DKK1 expression: high (H-score ≥35) vs low. Results 25 pts enrolled (01 Sept 2020 - 08 Apr 2021). Median age 61 years (22, 80); 17 pts gastroesophageal junction adenocarcinoma; 8 pts gastric cancer. 21 GEA pts had RNAscope DKK1 expression; 57% were DKK1-high. 22 of 25 pts had vCPS: 73% were vCPS
Bai, K;Norberg, SM;Sievers, C;Meyer, T;Friedman, J;Hinrichs, C;Allen, CT;
PMID: 35815785 | DOI: 10.1002/hed.27144
Immune checkpoint blockade can provide clinical benefit for patients with advanced cancer. Here, we report durable disease control over many years following PD-L1 blockade through induction of a viral antigen-specific T cell response in an adult patient with recurrent respiratory papillomatosis.Antigen-specific T cell response assays, single cell RNA-sequencing, and RNA-scope was used to study clinical tissues.An HPV6 E2-specific T cell clone restricted to HLA-B*55, present at low frequency in the pre-treatment papilloma, significantly expanded after six doses of PD-L1 blockade and remained present and functional at the site of initial response in the larynx as a tissue resident memory T cell for 4 years. An associated reduction in E2 target gene was observed following treatment.Although demonstrated in a single exceptional responder, these results highlight that immune checkpoint blockade may induce durable, viral antigen-specific immunity of sufficient magnitude to control disease in patients with nonmalignant disorders.