Tumor-secreted IFI35 promotes proliferation and cytotoxic activity of CD8+ T cells through PI3K/AKT/mTOR signaling pathway in colorectal cancer.

BACKGROUND: A large proportion of the patients with cancer do not respond to immunotherapies. Recent studies suggested an important role for tumor-infiltrating cytotoxic T lymphocytes (CTL) in enhancing response to immunotherapy. Here, we aim to identify gene that induce proliferative and cytotoxic states of CD8+ T cells, and to investigate its effect on CAR-T cells against colorectal cancer. METHODS: Correlation between the expression of IFI35 with the activation and cytotoxicity of CD8+ T cells was assessed with TCGA and proteomic databases. Then we constructed murine colon cancer cells over-expressing IFI35 and tested their effect on anti-tumor immunity in both immunodeficient and immunocompetent mouse models. Flow cytometry and immunohistochemistry were performed to assess the immune microenvironment. Western blot analysis was used to identify the potential down-stream signaling pathway regulated by IFI35. We further investigated the efficacy of the rhIFI35 protein in combination with immunotherapeutic treatment. RESULTS: The transcriptional and proteomic analysis of the activation and cytotoxicity of CD8+ T cells in human cancer samples demonstrated that IFI35 expression is correlated with increased CD8+ T cell infiltration and predicted a better outcome in colorectal cancer. The number and cytotoxicity of CD8+ T cells were significantly increased in IFI35-overexpressing tumors. Mechanistically, we identified that the IFNγ-STAT1-IRF7 axis stimulated IFI35 expression, and that IFI35-mediated regulation of CD8+ T cell proliferation and cytotoxicity was dependent on PI3K/AKT/mTOR signaling pathway in vitro. Furthermore, IFI35 protein enhanced the efficacy of CAR-T cells against colorectal cancer cells. CONCLUSION: Our findings identify IFI35 as a new biomarker that can enhance the proliferation and function of CD8+ T cells, as well as increase the efficacy of CAR-T cells against colorectal cancer cells.

LMP1-mediated glycolysis induces myeloid-derived suppressor cell expansion in nasopharyngeal carcinoma.

Myeloid-derived suppressor cells (MDSCs) are expanded in tumor microenvironments, including that of Epstein-Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC). The link between MDSC expansion and EBV infection in NPC is unclear. Here, we show that EBV latent membrane protein 1 (LMP1) promotes MDSC expansion in the tumor microenvironment by promoting extra-mitochondrial glycolysis in malignant cells, which is a scenario for immune escape initially suggested by the frequent, concomitant detection of abundant LMP1, glucose transporter 1 (GLUT1) and CD33+ MDSCs in tumor sections. The full process has been reconstituted in vitro. LMP1 promotes the expression of multiple glycolytic genes, including GLUT1. This metabolic reprogramming results in increased expression of the Nod-like receptor family protein 3 (NLRP3) inflammasome, COX-2 and P-p65 and, consequently, increased production of IL-1ß, IL-6 and GM-CSF. Finally, these changes in the environment of malignant cells result in enhanced NPC-derived MDSC induction. One key step is the physical interaction of LMP1 with GLUT1 to stabilize the GLUT1 protein by blocking its K48-ubiquitination and p62-dependent autolysosomal degradation. This work indicates that LMP1-mediated glycolysis regulates IL-1ß, IL-6 and GM-CSF production through the NLRP3 inflammasome, COX-2 and P-p65 signaling pathways to enhance tumor-associated MDSC expansion, which leads to tumor immunosuppression in NPC.

Prognostic value of estrogen receptor-α and progesterone receptor in curatively resected colorectal cancer: a retrospective analysis with independent validations.

BACKGROUND: Prognostic assessment is crucial for optimal treatment. The aim of our study was to investigate the potential impact of estrogen receptor-α (ER-α) and progesterone receptor (PR) on the prognosis of colorectal cancer (CRC) patients who received curative resection. METHODS: Retrospective evaluation of two independent cohorts of CRC patients maintained prospectively in 2009-2010 (training set) (n = 148) and 2007-2009 (internal validation set) (n = 485). Furthermore, we used an external independent CRC cohort from The Cancer Genome Atlas (TCGA) (n = 511) for further validation. ER-α and PR expression as well as other potential prognostic factors were retrospectively evaluated in training set with respect to overall survival (OS), local relapse free survival (LRFS) and distant metastasis free survival (DMFS). The prognostic factors found in training set will be validated in two validation cohorts. RESULTS: On univariate analysis for the training set, OS, LRFS and DMFS were not associated with PR expression. While patients with ER-αexpression were found to have poor prognosis. In addition, multivariate analysis showed that ER-αexpression maintained significance with respect to OS (HR, 5.06; p = 0.002), LRFS (HR, 8.81; p = 0.002) and DMFS (HR, 8.07; p = 0.004). Similarly, ER-α expression showed prognostic significance with respect to OS with hazard ratios (HRs) of 1.572 (95% CI: 1.001-2.467, p = 0.049) and 1.624 (95% CI: 1.047-2.520, p = 0.031) for the internal and external validation cohort, respectively. CONCLUSION: ER-α expression was a biomarker of poor prognosis and it might inform treatment decision for high risk CRC patients. However, PR expression was not associated with survival outcomes.

Exosomal miR-24-3p impedes T-cell function by targeting FGF11 and serves as a potential prognostic biomarker for nasopharyngeal carcinoma.

Recent studies have shown that extracellular microRNAs are not only potential biomarkers but are also involved in cell interactions to regulate the intercommunication between cancer cells and their microenvironments in various types of malignancies. In this study, we isolated exosomes from nasopharyngeal carcinoma (NPC) cell lines and patient sera (T-EXOs), or control NP69 cells and healthy donor sera (HD-EXOs). We found that miR-24-3p was markedly enriched in T-EXOs as compared with HD-EXOs; the serum exosomal miR-24-3p level was correlated with worse disease-free survival of patients (p < 0.05). Knockdown of exosomal miR-24-3p (miR-24-3p-sponge-T-EXOs) by a sponge RNA targeting miR-24-3p restored the T-EXO-mediated (control-sponge-T-EXO) inhibition of T-cell proliferation and Th1 and Th17 differentiation, and the induction of regulatory T cells (Tregs). Mechanistic analyses revealed that administration of exosomal miR-24-3p increased P-ERK, P-STAT1 and P-STAT3 expression while decreasing P-STAT5 expression during T-cell proliferation and differentiation. Moreover, by in vivo and in vitro assessments, we found FGF11 to be a direct target of miR-24-3p. However, both miR-24-3p-sponge-T-EXOs and T-EXOs (control-sponge-T-EXOs) impeded proliferation and Th1 and Th17 differentiation, but induced Treg differentiation, of lenti-shFGF11-transfected T cells. The levels of phosphorylated ERK and STAT proteins were different in lenti-ScshRNA-transfected T cells and lenti-shFGF11-transfected T cells following administration of miR-24-3p-sponge-T-EXO. Interestingly, tumour FGF11 expression was positively correlated with the number of CD4+ and CD8+ T cells in vivo, and predicted favourable patient DFS (p < 0.05). Additionally, hypoxia increased cellular and exosomal miR-24-3p levels and enhanced the inhibitory effect of T-EXO on T-cell proliferation and differentiation. Collectively, our findings suggest that exosomal miR-24-3p is involved in tumour pathogenesis by mediating T-cell suppression via repression of FGF11, and may serve as a potential prognostic biomarker in NPC. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Myeloid-derived suppressor cells inhibit T cell proliferation in human extranodal NK/T cell lymphoma: a novel prognostic indicator.

The expansion of myeloid-derived suppressor cells (MDSCs) and its correlation with advanced disease stage have been shown in solid cancers. Here, we investigated the functional features and clinical significance of MDSCs in extranodal NK/T cell lymphoma (ENKL). A higher percentage of circulating HLA-DR(-)CD33(+)CD11b(+) MDSCs was observed in ENKL patients than in healthy controls (P < 0.05, n = 32) by flow cytometry analysis. These MDSCs from ENKL patients (ENKL-MDSCs) consisted of CD14(+) monocytic (Mo-MDSCs, >60 %) and CD15(+) granulocytic (PMN-MDSCs, <20 %) MDSCs. Furthermore, these ENKL-MDSCs expressed higher levels of Arg-1, iNOS and IL-17 compared to the levels of MDSCs from healthy donors, and they expressed moderate levels of TGFß and IL-10 but lower levels of CD66b. The ENKL-MDSCs strongly suppressed the anti-CD3-induced allogeneic and autologous CD4 T cell proliferation (P < 0.05), but they only slightly suppressed CD8 T cell proliferation (P > 0.05). Interestingly, ENKL-MDSCs inhibited the secretion of IFNγ but promoted IL-10, IL-17 and TGFß secretion as well as Foxp3 expression in T cells. The administration of inhibitors of iNOS, Arg-1 and ROS significantly reversed the suppression of anti-CD3-induced T cell proliferation by MDSCs (P < 0.05). Importantly, based on multivariate Cox regression analysis, the HLA-DR(-)CD33(+)CD11b(+) cells and CD14(+) Mo-MDSCs were independent predictors for disease-free survival (DFS, P = 0.013 and 0.016) and overall survival (OS, P = 0.017 and 0.027). Overall, our results identified for the first time that ENKL-MDSCs (mainly Mo-MDSCs) have a prognostic value for patients and a suppressive function on T cell proliferation.

Tumor-induced myeloid-derived suppressor cells promote tumor progression through oxidative metabolism in human colorectal cancer.

BACKGROUND: Expansions of myeloid-derived suppressor cells (MDSCs) have been identified in human solid tumors, including colorectal cancer (CRC). However, the nature of these tumor-associated MDSCs and their interactions with tumor cells in CRC are still poorly understood. METHODS: The percentages and phenotype of MDSCs in peripheral blood and tumorous and paraneoplastic tissues from CRC patients, as well as the clinical relevance of these MDSCs, were assessed. Age-matched healthy donors were included as controls. The interaction between MDSCs and T cells or tumor cells was investigated in a coculture system in vitro, and the molecular mechanism of the effect of MDSCs on T cells or tumor cells was evaluated. RESULTS: We discovered that CRC patients had elevated levels of CD33(+)CD11b(+)HLA-DR(-) MDSCs in primary tumor tissues and in peripheral blood, and the elevated circulating MDSCs were correlated with advanced TNM stages and lymph node metastases. Radical resection significantly decreases the proportions of circulating MDSCs and CD4(+)CD25(high)FOXP3(+) regulatory T cells. In vitro, CRC cells mediate the promotion of MDSC induction. Moreover, these tumor-induced MDSCs could suppress T cell proliferation and promote CRC cell growth via cell-to-cell contact. Such effects could be abolished by the inhibition of oxidative metabolism, including the production of nitric oxide (NO), and reactive oxygen species (ROS). CONCLUSIONS: Our results reveal the functional interdependence between MDSCs, T cells and cancer cells in CRC pathogenesis. Understanding the impact of MDSCs on T cells and tumor cells will be helpful to establish an immunotherapeutic strategy in CRC patients.

Discovery of Kinetin in inhibiting colorectal cancer progression via enhancing PSMB1-mediated RAB34 degradation.

Colorectal cancer (CRC) is one of the most prevalent malignancies worldwide. Understanding the underlying mechanism driving CRC progression and identifying potential therapeutic drug targets are of utmost urgency. We previously utilized LC-MS-based proteomic profiling to identify proteins associated with postoperative progression in stage II/III CRC. Here, we revealed that proteasome subunit beta type-1 (PSMB1) is an independent predictor for postoperative progression in stage II/III CRC. Mechanistically, PSMB1 binds directly to onco-protein RAB34 and promotes its proteasome-dependent degradation, potentially leading to the inactivation of the MEK/ERK signaling pathway and inhibition of CRC progression. To further identify potential anticancer drugs, we screened a library of 2509 FDA-approved drugs using computer-aided drug design (CADD) and identified Kinetin as a potentiating agent for PSMB1. Functional assays confirmed that Kinetin enhanced the interaction between PSMB1 and RAB34, hence facilitated the degradation of RAB34 protein and decreased the MEK/ERK phosphorylation. Kinetin suppresses CRC progression in patient-derived xenograft (PDX) and liver metastasis models. Conclusively, our study identifies PSMB1 as a potential biomarker and therapeutic target for CRC, and Kinetin as an anticancer drug by enhancing proteasome-dependent onco-protein degradation.

PDP1 promotes KRAS mutant colorectal cancer progression by serving as a scaffold for BRAF and MEK1.

The oncogenic role of KRAS in colorectal cancer (CRC) progression is well-established. Despite this, identifying effective therapeutic targets for KRAS-mutated CRC remains a significant challenge. This study identifies pyruvate dehydrogenase phosphatase catalytic subunit 1 (PDP1) as a previously unrecognized yet crucial regulator in the progression of KRAS mutant CRC. A substantial upregulation of PDP1 expression is observed in KRAS mutant CRC cells and tissues compared to wild-type KRAS samples, which correlates with poorer prognosis. Functional experiments elucidate that PDP1 accelerates the malignance of KRAS mutant CRC cells, both in vitro and in vivo. Mechanistically, PDP1 acts as a scaffold, enhancing BRAF and MEK1 interaction and activating the MAPK signaling, thereby promoting CRC progression. Additionally, transcription factor KLF5 is identified as the key regulator for PDP1 upregulation in KRAS mutant CRC. Crucially, targeting PDP1 combined with MAPK inhibitors exhibits an obvious inhibitory effect on KRAS mutant CRC. Overall, PDP1 is underscored as a vital oncogenic driver and promising therapeutic target for KRAS mutant CRC.

The expressions of MIF and CXCR4 protein in tumor microenvironment are adverse prognostic factors in patients with esophageal squamous cell carcinoma.

BACKGROUND: Tumor-derived cytokines and their receptors usually take important roles in the disease progression and prognosis of cancer patients. In this survey, we aimed to detect the expression levels of MIF and CXCR4 in different cell populations of tumor microenvironments and their association with survivals of patients with esophageal squamous cell carcinoma (ESCC). METHODS: MIF and CXCR4 levels were measured by immunochemistry in tumor specimens from 136 resected ESCC. Correlation analyses and independent prognostic outcomes were determined using Pearson's chi-square test and Cox regression analysis. RESULTS: The expression of CXCR4 in tumor cells was positively associated with tumor status (P = 0.045) and clinical stage (P = 0.044); whereas the expression of CXCR4 in tumor-infiltrating lymphocytes (TILs) and the expression of MIF in tumor cells and in TILs were not associated with clinical parameters of ESCC patients. High MIF expression in tumor cells or in TILs or high CXCR4 expression in tumor cells was significantly related to poor survival of ESCC patients (P < 0.05). Multivariate analysis showed that the expression of MIF or CXCR4 in tumor cells and the expression of MIF in TILs were adverse independent factors for disease-free survival (DFS) and overall survival (OS) in the whole cohort of patients (P < 0.05). Furthermore, the expression of MIF and CXCR4 in tumor cells were independent factors for reduced DFS and OS in metastatic/recurrent ESCC patients (P < 0.05). Interestingly, the expressions of MIF and CXCR4 in tumor cells and in TILs were significantly positively correlated (P < 0.05), and the combined MIF and CXCR4 expression in tumor cells was an independent adverse predictive factor for DFS and OS (P < 0.05). CONCLUSION: The expressions of MIF and CXCR4 proteins in tumor cells and TILs have different clinically predictive values in ESCC.

Dynamic heterogeneity of colorectal cancer during progression revealed clinical risk-associated cell types and regulations in single-cell resolution and spatial context.

Background: Tumor heterogeneity is contributed by tumor cells and the microenvironment. Dynamics of tumor heterogeneity during colorectal cancer (CRC) progression have not been elucidated. Methods: Eight single-cell RNA sequencing (scRNA-seq) data sets of CRC were included. Milo was utilized to reveal the differential abundance of cell clusters during progression. The differentiation trajectory was imputed by using the Palantir algorithm and metabolic states were assessed by using scMetabolism. Three spatial transcription sequencing (ST-seq) data sets of CRC were used to validate cell-type abundances and colocalization. Cancer-associated regulatory hubs were defined as communication networks affecting tumor biological behaviors. Finally, quantitative reverse transcription polymerase chain reaction and immunohistochemistry staining were performed for validation. Results: TM4SF1+, SOX4+, and MKI67+ tumor cells; CXCL12+ cancer-associated fibroblasts; CD4+ resident memory T cells; Treg; IgA+ plasma cells; and several myeloid subsets were enriched in stage IV CRC, most of which were associated with overall survival of patients. Trajectory analysis indicated that tumor cells from patients with advanced-stage CRC were less differentiated, when metabolic heterogeneity showed a highest metabolic signature in terminal states of stromal cells, T cells, and myeloid cells. Moreover, ST-seq validated cell-type abundance in a spatial context and also revealed the correlation of immune infiltration between tertiary lymphoid structures and tumors followed by validation in our cohort. Importantly, analysis of cancer-associated regulatory hubs revealed a cascade of activated pathways including leukocyte apoptotic process, MAPK pathway, myeloid leukocyte differentiation, and angiogenesis during CRC progression. Conclusions: Tumor heterogeneity was dynamic during progression, with the enrichment of immunosuppressive Treg, myeloid cells, and fibrotic cells. The differential state of tumor cells was associated with cancer staging. Assessment of cancer-associated regulatory hubs suggested impaired antitumor immunity and increased metastatic ability during CRC progression.

Reprogramming of palmitic acid induced by dephosphorylation of ACOX1 promotes ß-catenin palmitoylation to drive colorectal cancer progression.

Metabolic reprogramming is a hallmark of cancer. However, it is not well known how metabolism affects cancer progression. We identified that metabolic enzyme acyl-CoA oxidase 1 (ACOX1) suppresses colorectal cancer (CRC) progression by regulating palmitic acid (PA) reprogramming. ACOX1 is highly downregulated in CRC, which predicts poor clinical outcome in CRC patients. Functionally, ACOX1 depletion promotes CRC cell proliferation in vitro and colorectal tumorigenesis in mouse models, whereas ACOX1 overexpression inhibits patient-derived xenograft growth. Mechanistically, DUSP14 dephosphorylates ACOX1 at serine 26, promoting its polyubiquitination and proteasomal degradation, thereby leading to an increase of the ACOX1 substrate PA. Accumulated PA promotes ß-catenin cysteine 466 palmitoylation, which inhibits CK1- and GSK3-directed phosphorylation of ß-catenin and subsequent ß-Trcp-mediated proteasomal degradation. In return, stabilized ß-catenin directly represses ACOX1 transcription and indirectly activates DUSP14 transcription by upregulating c-Myc, a typical target of ß-catenin. Finally, we confirmed that the DUSP14-ACOX1-PA-ß-catenin axis is dysregulated in clinical CRC samples. Together, these results identify ACOX1 as a tumor suppressor, the downregulation of which increases PA-mediated ß-catenin palmitoylation and stabilization and hyperactivates ß-catenin signaling thus promoting CRC progression. Particularly, targeting ß-catenin palmitoylation by 2-bromopalmitate (2-BP) can efficiently inhibit ß-catenin-dependent tumor growth in vivo, and pharmacological inhibition of DUSP14-ACOX1-ß-catenin axis by Nu-7441 reduced the viability of CRC cells. Our results reveal an unexpected role of PA reprogramming induced by dephosphorylation of ACOX1 in activating ß-catenin signaling and promoting cancer progression, and propose the inhibition of the dephosphorylation of ACOX1 by DUSP14 or ß-catenin palmitoylation as a viable option for CRC treatment.

High-throughput proteomics profiling-derived signature associated with chemotherapy response and survival for stage II/III colorectal cancer.

Adjuvant chemotherapy (ACT) is usually used to reduce the risk of disease relapse and improve survival for stage II/III colorectal cancer (CRC). However, only a subset of patients could benefit from ACT. Thus, there is an urgent need to identify improved biomarkers to predict survival and stratify patients to refine the selection of ACT. We used high-throughput proteomics to analyze tumor and adjacent normal tissues of stage II/III CRC patients with /without relapse to identify potential markers for predicting prognosis and benefit from ACT. The machine learning approach was applied to identify relapse-specific markers. Then the artificial intelligence (AI)-assisted multiplex IHC was performed to validate the prognostic value of the relapse-specific markers and construct a proteomic-derived classifier for stage II/III CRC using 3 markers, including FHL3, GGA1, TGFBI. The proteomics profiling-derived signature for stage II/III CRC (PS) not only shows good accuracy to classify patients into high and low risk of relapse and mortality in all three cohorts, but also works independently of clinicopathologic features. ACT was associated with improved disease-free survival (DFS) and overall survival (OS) in stage II (pN0) patients with high PS and pN2 patients with high PS. This study demonstrated the clinical significance of proteomic features, which serve as a valuable source for potential biomarkers. The PS classifier provides prognostic value for identifying patients at high risk of relapse and mortality and optimizes individualized treatment strategy by detecting patients who may benefit from ACT for survival.

Cancer-associated fibroblasts undergoing neoadjuvant chemotherapy suppress rectal cancer revealed by single-cell and spatial transcriptomics.

Neoadjuvant chemotherapy (NAC) for rectal cancer (RC) shows promising clinical response. The modulation of the tumor microenvironment (TME) by NAC and its association with therapeutic response remain unclear. Here, we use single-cell RNA sequencing and spatial transcriptome sequencing to examine the cell dynamics in 29 patients with RC, who are sampled pairwise before and after treatment. We construct a high-resolution cellular dynamic landscape remodeled by NAC and their associations with therapeutic response. NAC markedly reshapes the populations of cancer-associated fibroblasts (CAFs), which is strongly associated with therapeutic response. The remodeled CAF subsets regulate the TME through spatial recruitment and crosstalk to activate immunity and suppress tumor progression through multiple cytokines, including CXCL12, SLIT2, and DCN. In contrast, the epithelial-mesenchymal transition of malignant cells is upregulated by CAF_FAP through MIR4435-2HG induction, resulting in worse outcomes. Our study demonstrates that NAC inhibits tumor progression and modulates the TME by remodeling CAFs.

The Role of RAB GTPases and Its Potential in Predicting Immunotherapy Response and Prognosis in Colorectal Cancer.

Background: Colorectal cancer (CRC) is the third most common cancer worldwide, in which aberrant activation of the RAS signaling pathway appears frequently. RAB proteins (RABs) are the largest Ras small GTPases superfamily that regulates intracellular membrane trafficking pathways. The dysregulation of RABs have been found in various diseases including cancers. Compared with other members of Ras families, the roles of RABs in colorectal cancer are less well understood. Methods: We analyzed the differential expression and clinicopathological association of RABs in CRC using RNA sequencing and genotyping datasets from TCGA samples. Moreover, the biological function of RAB17 and RAB34 were investigated in CRC cell lines and patient samples. Results: Of the 62 RABs we analyzed in CRC, seven (RAB10, RAB11A, RAB15, RAB17, RAB19, RAB20, and RAB25) were significantly upregulated, while six (RAB6B, RAB9B, RAB12, RAB23, RAB31, and RAB34) were significantly downregulated in tumor tissues as compared to normal. We found that the upregulated-RABs, which were highly expressed in metabolic activated CRC subtype (CMS3), are associated with cell cycle related pathways enrichment and positively correlated with the mismatch repair (MMR) genes in CRC, implying their role in regulating cell metabolism and tumor growth. While, high expression of the downregulated-RABs were significantly associated with poor prognostic CRC mesenchymal subtypes (CMS4), immune checkpoint genes, and tumor infiltrating immune cells, indicating their role in predicting prognosis and immunotherapy efficacy. Interestingly, though RAB34 mRNA is downregulated in CRC, its high expression is significantly associated with poor prognosis. In vitro experiments showed that RAB17 overexpression can promote cell proliferation via cell cycle regulation. While, RAB34 overexpression can promote cell migration and invasion and is associated with PD-L1/PD-L2 expression increase in CRC cells. Conclusions: Our study showed that RABs may play important roles in regulating cell cycle and immune-related pathways, therefore might be potential biomarkers in predicting prognosis and immunotherapy response in CRC.

Comparative Safety, Efficacy and Survival Outcome of Anti-PD-1 Immunotherapy in Colorectal Cancer Patients With vs Without Hepatitis B Virus Infection: A Multicenter Cohort Study.

INTRODUCTION: Antiprogrammed cell death protein-1 (PD-1) immunotherapy has substantially broadened in scope for the treatment of colorectal cancer (CRC). However, comparative safety, efficacy and survival outcome of anti-PD-1 therapy in CRC patients with and without hepatitis B virus (HBV) infection remain unclear. METHODS: This multicenter, retrospective cohort study included 180 advanced-stage CRC patients with available serological markers for HBV infection treated with anti-PD-1 therapy at the Sixth Affiliated Hospital, Sun Yat-sen University and Sun Yat-sen University Cancer Center between December 2016 and December 2019. A propensity score-matched analysis was performed to compare the safety, efficacy, and survival outcome between HBV and non-HBV groups. RESULTS: The incidences of deficient mismatch repair and metastatic disease were significantly different between HBV and non-HBV groups (both P < 0.05). After propensity score-matched analysis, any grade immune-related adverse events and grade ≥ 3 immune-related adverse events were 47% vs 38% (P = 0.25) and 5% vs 6% (P = 1.0) between HBV and non-HBV groups, respectively. The overall response rate was 39% with 17 complete responses and 13 partial responses for the HBV infection cohort and 39% with 11 complete responses and 19 partial responses for the non-HBV infection cohort (P = 1.0). Two-year progression-free survival rates were 38% vs 40% (P = 0.596) and 2-year overall survival rates were 55% vs 63% (P = 0.401) for HBV vs non-HBV infection cohorts. DISCUSSION: The incidences of toxicity, efficacy and survival outcome were similar between patients with HBV infection and non-HBV patients receiving anti-PD-1 therapy, which supports to include CRC patients with HBV in clinical trials of anti-PD-1 therapy.

TSG-6 promotes Cancer Cell aggressiveness in a CD44-Dependent Manner and Reprograms Normal Fibroblasts to create a Pro-metastatic Microenvironment in Colorectal Cancer.

Tumor necrosis factor α stimulated gene 6 (TSG-6), a 30-KD secretory protein, plays an essential role in modulating inflammatory responses and extracellular matrix remodeling. However, little is known regarding the role of TSG-6 in human cancers. Here, we investigated the mechanism of action and the role of TSG-6 in colorectal cancer (CRC) metastasis. We found that TSG-6 was highly expressed in tumor tissues and was associated with poor prognosis and metastasis in CRC. Mechanistically, TSG-6 overexpression in CRC cells resulted in ERK activation and epithelial-mesenchymal transition by means of stabilizing CD44 and facilitating the CD44-EGFR complex formation on the cell membrane. Consequently, this resulted in the promotion of tumor migration and invasion both in vitro and in vivo. Notably, our data showed that CRC cells secreted TSG-6 could trigger a paracrine activation of JAK2-STAT3 signaling and reprogram normal fibroblasts into cancer-associated fibroblasts, which exhibited upregulation of pro-metastatic cytokines (CCL5 and MMP3) and higher movement ability. In animal models, the co-injection of cancer cells and TSG6-reprogrammed fibroblasts led to a significant increase in tumor metastasis. Our findings indicated that TSG-6 overexpression in CRC cells could promote cancer metastasis in both an autocrine and paracrine manner. Therefore, targeting TSG-6 might be a potential therapeutic strategy for the treatment of metastatic CRC.

OLFM4 deficiency delays the progression of colitis to colorectal cancer by abrogating PMN-MDSCs recruitment.

Chronic inflammatory bowel disease (IBD) is strongly associated with the development of colitis-associated tumorigenesis (CAT). Despite recent advances in the understanding of polymorphonuclear myeloid-derived suppressor cell (PMN-MDSC) responses in cancer, the mechanisms of these cells during this process remain largely uncharacterized. Here, we discovered a glycoprotein, olfactomedin-4 (OLFM4), was highly expressed in PMN-MDSCs from colitis to colorectal cancer (CRC), and its expression level and PMN-MDSC population positively correlated with the progression of IBD to CRC. Moreover, mice lacking OLFM4 in myeloid cells showed poor recruitment of PMN-MDSCs, impaired intestinal homeostasis, and delayed development from IBD to CRC, and increased response to anti-PD1 therapy. The main mechanism of OLFM4-mediated PMN-MDSC activity involved the NF-κB/PTGS2 pathway, through the binding of LGALS3, a galactoside-binding protein expressed on PMN-MDSCs. Our results showed that the OLFM4/NF-κB/PTGS2 pathway promoted PMN-MDSC recruitment, which played an essential role in the maintenance of intestinal homeostasis, but showed resistance to anti-PD1 therapy in CRC.

Association of Peripheral Blood Biomarkers With Response to Anti-PD-1 Immunotherapy for Patients With Deficient Mismatch Repair Metastatic Colorectal Cancer: A Multicenter Cohort Study.

Purpose: Deficient mismatch repair (dMMR) is an established biomarker for the response to the programmed cell death (PD)-1 inhibitors in metastatic colorectal cancer (mCRC). Although patients with dMMR mCRC could achieve a high incidence of disease control and favorable progression-free survival (PFS), reported response rates to PD-1 inhibitors are variable from 28% to 52%. We aimed to explore the additional predictive biomarkers associated with response to anti-PD-1 immunotherapy in patients with dMMR mCRC. Methods: This multicenter cohort study enrolled patients with dMMR mCRC receiving anti-PD-1 immunotherapy at the Sixth Affiliated Hospital of Sun Yat-sen University and Sun Yat-sen University Cancer Center between December 2016 and December 2019. The total information of 20 peripheral blood biomarkers, including T cells (frequency of CD4+ T cell, frequency of CD8+ T cell, and ratio of CD4+/CD8+), carcinoembryonic antigen (CEA), inflammatory markers, and lipid metabolism markers, was collected. The association between response or survival and peripheral blood parameters was analyzed. Results: Among the tested parameters, the ratio of CD4+/CD8+ and frequency of CD4+ T cell were significantly associated with PFS (p = 0.023, p = 0.012) and overall survival (OS; p = 0.027, p = 0.019) in a univariate analysis. A lower level of CD4+/CD8+ ratio or frequency of CD4+ T cell showed a significant association with better overall response rates (ORRs; p = 0.03, p = 0.01). The ratio of CD4+/CD8+ and frequency of CD4+ T cell maintained significance in multivariate Cox model for PFS (HR = 9.23, p = 0.004; HR = 4.83, p = 0.02) and OS (HR = 15.22, p = 0.009; HR = 16.21, p = 0.025). Conclusion: This study indicated that the ratio of CD4+/CD8+ and the frequency of CD4+ T cell might be crucial independent biomarkers within dMMR mCRC to better identify patients for anti-PD-1 immunotherapy. If validated in prospective clinical trials, the ratio of CD4+/CD8+ and the frequency of CD4+ T cell might aid in guiding the treatment of PD-1 inhibitors among patients with dMMR mCRC.

Development and validation of an individualized gene expression-based signature to predict overall survival in metastatic colorectal cancer.

BACKGROUND: Metastatic colorectal cancer (mCRC) is a heterogeneous disease. Predictive biomarkers are in great demand to optimize patient selection at high risk for death and to provide a novel insight into potential targeted therapy. METHODS: The present study retrospectively analyzed the gene expression profiles of tumor tissue samples from 4 public CRC cohorts, including 1 RNA-Seq data set from The Cancer Genome Atlas (TCGA) CRC cohort and 3 microarray data sets from GEO. Prognostic analysis was performed to test the predictive value of prognostic gene signature. RESULTS: Of 192 patients, 108 patients (56.3%) were men and median age was 65 years. A prognostic gene signature that consisted of 15 unique genes was generated in the discovery cohort. In the meta-validation cohorts, the signature significantly classified patients into high-risk and low-risk groups with regard to overall survival (OS) in mCRC patients with advanced stage disease and remained as an independent prognostic marker in multivariable analysis (1.57; 95% CI: 1.16-2.11; P=0.003) after adjusting for clinical parameters and molecular types. Gene Set Enrichment Analysis showed that several biological processes, including angiogenesis (P<0.001), epithelial mesenchymal transit (P<0.001) and inflammatory response (P=0.001), were enriched among this prognostic gene signature. CONCLUSIONS: The proposed prognostic gene signature is a promising prognostic tool to estimate OS in mCRC. Prospective larger studies to examine the clinical utility of the biomarkers to guide individualized treatment of mCRC are warranted.

The Predictive Value of Estrogen Receptor 1 on Adjuvant Chemotherapy in Locally Advanced Colorectal Cancer: A Retrospective Analysis With Independent Validation and Its Potential Mechanism.

Purpose: To investigate the predictive biomarker value of estrogen receptor 1 (ESR1) expression in tumor tissue on adjuvant chemotherapy in curatively resected colorectal cancer (CRC). Methods: A total of 467 CRC patients in 2007-2010 were retrospectively evaluated. Clinical information and follow-up data were retrieved from hospital registries and patient files. What's more, we used an external independent cohort (n = 511) from GSE39582 for further validation. Overall survival was estimated by the Kaplan-Meier method, and the survival curves were compared by log-rank tests. Cox proportional hazards models were used for multivariate analyses to calculate the hazard ratios (HRs) and test independent significance. Immunohistochemistry and Western blot were applied to detect protein expression of ESR1 in CRC patients and cell lines. The stable knockdown and overexpressed cells were transduced with the lentivirus. Cell viability was measured by an MTS reagent. Results: The predictive value of ESR1 was investigated in locally advanced CRC patients. Kaplan-Meier analysis indicated that ESR1 expression was significantly correlated with OS in patients receiving adjuvant chemotherapy from these cohorts, with p = 0.015 and p < 0.001, respectively. ESR1 expression was significantly correlated with 5-flurouracil (5-FU)-based adjuvant chemotherapy in training with an HR of 1.792 (95%CI: 1.100-2.921, p = 0.019). Downregulation of ESR1 was related with enhanced chemosensitivity to 5-FU in CRC cell lines, while upregulation of ESR1 was correlated with decreased chemosensitivity. Conclusions: The present study manifest clinical validity of ESR1 expression as a predictive biomarker on 5-FU-based adjuvant chemotherapy in stage II-III CRC.