Impaired immunity in late stage cancer patients is not limited to anti-tumor responses, as demonstrated by poor vaccination protection and high susceptibility to infection 1 – 3 . This has been largely attributed to chemotherapy-induced impairment of innate immunity such as neutropenia 2 , whereas systemic effects of tumors on hematopoiesis and adoptive immunity remain incompletely understood. Here we observed anemia associated with severe deficiency of CD8 + T cell responses against pathogens in treatment-naïve mice bearing large tumors. Specifically, we identify CD45 + erythroid progenitor cells (CD71 + TER119 + , EPCs) as robust immunosuppressors. CD45 + EPCs, induced by tumor growth-associated extramedullary hematopoiesis, accumulate in the spleen to become a major population, outnumbering regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs). The CD45 + EPC transcriptome closely resembles that of MDSCs, and, like MDSCs, reactive oxygen species production is a major mechanism underlying CD45 + EPC-mediated immunosuppression. Similarly, an immunosuppressive CD45 + EPC population was detected in cancer patients with anemia. These findings identify a major population of immunosuppressive cells that likely contributes to the impaired T cell responses commonly observed in advanced cancer patients.

Epstein-Barr virus (EBV) infection is ubiquitous worldwide and is associated with multiple cancers, including nasopharyngeal carcinoma (NPC). The importance of EBV viral genomic variation in NPC development and its striking epidemic in southern China has been poorly explored. Through large-scale genome sequencing of 270 EBV isolates and two-stage association study of EBV isolates from China, we identified two non-synonymous EBV variants within BALF2 strongly associated with the risk of NPC (odds ratio (OR) = 8.69, P=9.69×10−25 for SNP 162476_C; OR = 6.14, P=2.40×10−32 for SNP 163364_T). The cumulative effects of these variants contributed to 83% of the overall risk of NPC in southern China. Phylogenetic analysis of the risk variants revealed a unique origin in Asia, followed by clonal expansion in NPC-endemic regions. Our results provide novel insights into NPC endemic in southern China and also enable the identification of high-risk individuals for NPC prevention.

The concept of cancer stem cells (CSCs) proposes that solely CSCs are capable of generating tumor metastases. However, how CSCs maintain their invasion and migration abilities, the most important properties of metastatic cells, still remains elusive. Here we used CD133 to mark a specific population from human ovarian cancer cell line and ovarian cancer tissue and determined its hyperactivity in migration and invasion. Therefore, we labeled this population as cancer stem-like cells (CSLCs). In comparison to CD1332 non-CSLCs, chemokine CCL5 and its receptors, CCR1, CCR3, and CCR5, were consistently upregulated in CSLCs, and most importantly, blocking of CCL5, CCR1, or CCR3 effectively inhibits the invasive capacity of CSLCs. Mechanistically, we identified that this enhanced invasiveness is mediated through nuclear factor jB (NF-jB) activation and the consequently elevated MMP9 secretion. Our results suggested that the autocrine activation of CCR1 and CCR3 by CCL5 represents one of major mechanisms underlying the metastatic property of ovarian CSLCs.

BackgroundCCN family, comprising six members (Cyr61, CTGF, Nov, WISP-1, WISP-2, WISP-3), is involved in the stimulation of cell proliferation, migration, adhesion, angiogenesis, and tumorigenesis. Several studies have shown that expression of Cyr61, CTGF, and WISP-1 affects the tumorigenic potential of lung cancer cells in vitro. However, the correlation of expression of CCN family proteins and clinical features of lung cancer remains unknown.Methodology and Principal FindingsIn the present work, we quantified the mRNA levels of Cyr61, CTGF, and WISP-1 in samples from 60 primary lung cancers and their matched normal lung tissues by quantitative real-time PCR assay. Downregulation of the Cyr61 and CTGF genes and upregulation of the WISP-1 gene were found in primary lung cancers compared to the paired normal lung tissues. Immunohistochemistry analysis also disclosed a similar expression pattern of Cyr61, CTGF, and WISP-1 protein in paired lung cancer tissues. Statistical analysis revealed significant associations between expression of either Cyr61 or CTGF with tumor stage, tumor histology, metastasis, smoking, and family history at diagnosis. A significant correlation also existed between WISP-1 expression with tumor histology, and patient age. Moreover, expression levels of Cyr61 and CTGF correlated with survival of the lung-cancer patients.ConclusionsOur results suggest that Cyr61, CTGF, and WISP-1 might be implicated in the development and progression of primary lung cancers, and their levels might serve as valuable prognostic markers, as well as potential targets for therapeutic intervention.

BaCKgRoUND aND aIMS: Cancer-associated fibroblasts (CAFs) are key players in multicellular, stromal-dependent alterations leading to HCC pathogenesis. However, the intricate crosstalk between CAFs and other components in the tumor microenvironment (TME) remains unclear. This study aimed to investigate the cellular crosstalk among CAFs, tumor cells, and tumor-associated neutrophils (TANs) during different stages of HCC pathogenesis. appRoaCH aND ReSUltS: In the HCC-TME, CAFderived cardiotrophin-like cytokine factor 1 (CLCF1) increased chemokine (C-X-C motif ) ligand 6 (CXCL6) and TGFβ secretion in tumor cells, which subsequently promoted tumor cell stemness in an autocrine manner and TAN infiltration and polarization in a paracrine manner. Moreover, CXCL6 and TGFβ secreted by HCC cells activated extracellular signal-regulated kinase (ERK) 1/2 signaling of CAFs to produce more CLCF1, thus forming a positive feedback loop to accelerate HCC progression. Inhibition of ERK1/2 or CLCF1/ciliary neurotrophic factor receptor signaling efficiently impaired CLCF1-mediated crosstalk among CAFs, tumor cells, and TANs both in vitro and in vivo. In clinical samples, up-regulation of the CLCF1−CXCL6/TGFβ axis exhibited a marked correlation with increased cancer stem cells, "N2"-polarized TANs, tumor stage, and poor prognosis. CoNClUSIoNS:This study reveals a cytokine-mediated cellular crosstalk and clinical network involving the CLCF1− CXCL6/TGFβ axis, which regulates the positive feedback loop among CAFs, tumor stemness, and TANs, HCC progression, and patient prognosis. These results may support the CLCF1 cascade as a potential prognostic biomarker and suggest that selective blockade of CLCF1/ciliary neurotrophic factor receptor or ERK1/2 signaling could provide an effective therapeutic target for patients with HCC. (Hepatology 2021;73:1717-1735. M ore than 80% of HCCs are characterized by extensive liver fibrosis caused by the activation, proliferation, and accumulation of fibroblasts. (1) A hallmark feature of the tumor microenvironment (TME) of HCC is the mass of cancer-associated fibroblasts (CAFs), which has been extensively reported to influence HCC progression. (1)

Connective tissue growth factor (CTGF or CCN2), a member of the CCN family, is involved in diverse biological processes such as cell adhesion, proliferation, and angiogenesis. In this study, we show that overexpression of CTGF occurred in a significant proportion of esophageal squamous cell carcinoma (ESCC) samples that were of a high tumor grade and metastatic.

Epstein-Barr virus (EBV)-associated epithelial cancers, including nasopharyngeal carcinoma (NPC) and approximately 10% of gastric cancers, termed EBVaGC, represent 80% of all EBV-related malignancies. However, the exact role of EBV in epithelial cancers remains elusive. Here, we report that EBV functions in vasculogenic mimicry (VM). Epithelial cancer cells infected with EBV develop tumor vascular networks that correlate with tumor growth, which is different from endothelial-derived angiogenic vessels and is VEGF-independent. Mechanistically, activation of the PI3K/AKT/mTOR/HIF-1α signaling cascade, which is partly mediated by LMP2A, is responsible for EBV-induced VM formation. Both xenografts and clinical samples of NPC and EBVaGC exhibit VM histologically, which are correlated with AKT and HIF-1α activation. Furthermore, although anti-VEGF monotherapy shows limited effects, potent synergistic antitumor activities are achieved by combination therapy with VEGF and HIF-1α-targeted agents. Our findings suggest that EBV creates plasticity in epithelial cells to express endothelial phenotype and provides a novel EBV-targeted antitumor strategy.

Inflammatory cytokines, components of cancer stem cells (CSCs) niche, could affect the characteristics of CSCs such as self-renewal and metastasis. Interleukin-17 (IL-17) is a new pro-inflammatory cytokine mainly produced by T-helper (Th17) cells and macrophages. The effects of IL-17 on the characteristics of CSCs remain to be explored. Here we first demonstrated a role of IL-17 in promoting the self-renewal of ovarian CD133(+) cancer stem-like cells (CSLCs). We detected IL-17-producing cells (CD4(+) cells and CD68(+) macrophages) in the niche of CD133(+)CSLCs. Meanwhile, there was IL-17 receptor expression on CD133(+)CSLCs derived from A2780 cell line and primary ovarian cancer tissues. By recombinant human IL-17 stimulation and IL-17 transfection, the growth and sphere formation capacities of ovarian CD133(+)CSLCs were significantly enhanced in a dose-dependent manner. Moreover, ovarian CD133(+)CSLCs transfected with IL-17 showed greater tumorigenesis capacity in nude mice. These data suggest that IL-17 promoted the self-renewal of ovarian CD133(+)CSLCs. Further investigation through gene profiling revealed that the stimulation function of IL-17 on self-renewal of ovarian CD133(+)CSLCs might be mediated by the nuclear factor (NF)-κB and p38 mitogen-activated protein kinases (MAPK) signaling pathway. NF-κB and p38 MAPK were activated by IL-17. More importantly, IL-17-promoted self-renewal was inhibited by specific inhibitors of NF-κB and p38 MAPK. Taken together, our data indicate that IL-17 contributed to ovarian cancer malignancy through promoting the self-renewal of CD133(+)CSLCs and that IL-17 and its signaling pathway might serve as therapeutic targets for the treatment of ovarian cancer.