lncRNA/miR-29c-Mediated High Expression of LOX Can Influence the Immune Status and Chemosensitivity and Can Forecast the Poor Prognosis of Gastric Cancer

Gastric carcinoma is the fourth most prevalent cause of cancer-related deaths worldwide because of dismal prognosis and few therapeutic options. Accumulated studies have indicated that targeting lysyl oxidase (LOX) family members may serve as an anticancer strategy. Nevertheless, the specific mechanisms of LOX in stomach carcinoma are still unclear. In this study, we demonstrated that LOX is significantly different in 13 types of cancers and may act as a potential therapeutic target, especially in stomach carcinoma. Moreover, overexpression of LOX in gastric carcinoma was validated by multiple databases and contributed to the poor overall survival (OS), progression-free survival (PFS) and post-progression survival (PPS) of stomach adenocarcinoma (STAD) patients. Next, based on the ceRNA hypothesis, the HIF1A-AS2/RP11-366L20.2-miR-29c axis was characterized as the upstream regulatory mechanism of LOX gene overexpression in gastric cancer by combining correlation analysis, expression analysis, and survival analysis. Finally, we illustrated that LOX gene overexpression leads to dismal prognosis of gastric cancer, perhaps through promoting M2 macrophage polarization and tumor immune escape and enhancing drug resistance of tumor cells to chemotherapeutic drugs. Our research demonstrate that LOX may be potentially applied as a novel prognostic marker and targeting inhibition of LOX holds promise as a treatment strategy for gastric cancer.

Prognostic Value of PD-L1 and Siglec-15 Expression in Patients with Nasopharyngeal Carcinoma

Purpose: Sialic acid-binding immunoglobulin-like lectin 15 (Siglec-15) might be involved in the activation of important pathways related to tumor immune escape, along with programmed death-ligand 1 (PD-L1). We aimed to investigate the correlation between the expression of Siglec-15 and PD-L1 in NPC patients.Patients and methods: We determined the expression of PD-L1 via immunohistochemical staining and that of Siglec-15 via immunofluorescent staining in 182 NPC tissue samples.Results: A significant correlation was identified between the PD-L1 and Siglec-15 expression (P=0.000). Moreover, Kaplan–Meier survival curves showed that PD-L1 expression were associated with improved overall survival (P=0.025) and Siglec-15 expression were associated with improved distant failure-free survival (P=0.048). Meanwhile, multivariate Cox analysis showed that PD-L1 and Siglec-15 were independent predictors of overall survival (P=0.020) and distant failure-free survival (P=0.047), respectively. The results of the log-rank test and Cox regression analyses showed that patients exhibiting no PD-L1/Siglec-15 expression were found to have significant advantages with regard to overall survival, compared to other groups (P=0.037).Conclusion: PD-L1 and Siglec-15 may represent novel biomarkers for predicting NPC patient prognosis. Siglec-15 could be considered as a potential target for the development of therapeutics for NPC treatment in the future.

A4GALT Mediated the Glycosylation of B7-H3 in Human Colorectal Cancer Cell Lines

B7-H3 is one of the most important members of the B7/CD28 family, and its expression level is abnormally high in a variety of tumors. B7-H3 inhibits T cell activation via binding to the corresponding receptors on T cells, thereby mediating tumor immune escape. Glycosylation is a common post-translational modification of proteins, which plays an essential role in protein expression patterns and biological functions. Current evidence has shown that the abnormal glycosylation of B7-H3 in tumors is of great significance for protein expression and ligand-receptor binding. Therefore, in-depth exploration of the underlying mechanism of glycosylation modification of B7-H3 is expected to provide new insights for tumor immunotherapy. To investigate the underlying mechanism of glycosyltransferase-mediated glycosylation of B7-H3. Firstly, the CHIPBase database was used to screen glycosyltransferases with a high correlation with the protein expression of B7-H3. Then their siRNAs were designed and synthesized to transfect into cells, and the western blotting assay was performed for further screening. Secondly, the siRNA and overexpression plasmid of the screened glycosyltransferase were respectively transfected into cells to verify the effect on the expression level of B7-H3. Thirdly, the effect of glycosyltransferase on the expression level of B7-H3 was explored by changing its substrate level. Finally, the co-immunoprecipitation experiment was conducted to verify whether protein binding existed between B7-H3 and the glycosyltransferase. The glycosyltransferase called A4GALT had the highest correlation with the protein expression of B7-H3. After knocking down or overexpressing A4GALT, the protein expression level of B7-H3 both changed significantly. When knocked down GALT to reduce the galactosyl donors, B7-H3 was significantly down-regulated. And B7-H3 was up-regulated while increasing the galactose in the medium. In addition, the Co-immunoprecipitation experiment proved that there was protein binding between B7-H3 and A4GALT. A4GALT can positively regulate the expression of B7-H3, and changing the level of galactosyl donors can also positively regulate the expression of B7-H3. There is a protein interaction between A4GALT and B7-H3.

Butyrate Impedes the Recruitment of MDSCs to Alleviate CAC Development by Inhibition of the TLR2/MyD88/NF-κB Signaling Pathway

Background: The colitis-associated colorectal cancer (CAC) with inflammatory bowel disease (IBD) serving as its prelude often has a poor prognosis due to the hysteretic diagnosis. As a representative of short chain fatty acids (SCFAs), butyrate has been proved to have obvious antitumor effect. Here, we aimed to examine its effect on CAC and possible mechanism in tumor microenvironment (TME).Method: The establishment of CAC mouse model was mainly based on the combination of AOM intraperitoneal injection and DSS three cycle. HE staining was used to analyze the degree of colonic inflammation and tumor dysplasia. The proportion of MDSCs population was mainly evaluated by flow cytometry assay. RT-PCR, immunohistochemical staining and western blot analysis was carried out to detect protein molecular expression.Results: In our current study, the AOM-DSS induced CAC mouse model was utilized to evaluate the effect of butyrate on CAC. The administration of butyrate significantly improved the weight loss, falling survival rate, higher DAI index and anal prolapse caused by the AOM-DSS during the CAC modeling process. Anatomical results including the size and number of tumors and histological results including the abnormal hyperplasia shown by HE staining also confirmed the inhibitory effect of butyrate on CAC. In addition, the proportion of myeloid-derived suppressor cells (MDSCs) assisting tumor immune escape in tumor microenvironment (TME) decreased under the intervention of butyrate. And inflammatory mediators including CCL2, IL-6 and TNF-α in TME that induce the recruitment of MDSCs showed the same trend as MDSCs. Toll-like receptor 2 (TLR2) as a receptor molecule related to inflammation and immune function was also up-regulated in CAC, accompanied by the synchronous up-regulation of downstream Myd88 and NF-κB molecules, while the use of butyrate significantly inhibited the up-regulation of these molecules.Conclusions: Butyrate might reduce the release of CCL2, IL-6 and TNF-α in TME by inhibiting TLR2/MyD88/NF-κB signaling pathway to reduce the recruitment of MDSCs in TME, which eventually weakened the immune escape of tumors and retarded the progress of CAC.

Novel Combinations of Human Immunomodulatory mAbs Lacking Cardiotoxic Effects for Therapy of TNBC

Triple-negative breast cancer (TNBC) is a highly aggressive subtype of breast cancer characterized by a higher mortality rate among breast cancer subtypes. Poly(ADP-ribose) polymerase (PARP) inhibitors are used in clinics to treat a subgroup of TNBC patients, but other targeted therapies are urgently needed. Programmed death-ligand 1 (PD-L1), involved in tumor immune escape, was recently identified as a target for TNBC; accordingly, the anti-PD-L1 monoclonal antibody (mAb), atezolizumab, has been approved by FDA in combination with Paclitaxel for the therapy of metastatic TNBC. Here, we tested novel combinations of fully human immunomodulatory mAbs, including anti-PD-L1 mAbs generated in our laboratory and atezolizumab, on TNBC and other tumor cell lines. We evaluated their anti-tumor efficacy when used as single agents or in combinatorial treatments with anti-CTLA-4 mAbs in in vitro co-cultures of hPBMCs with tumor cells, by measuring tumor cell lysis and IL-2 and IFNγ cytokines secretion by lymphocytes. In parallel, by using co-cultures of hPBMCs and cardiomyocytes, we analyzed the potential cardiotoxic adverse side effects of the same antibody treatments by measuring the cardiac cell lysis and the secretion of pro-inflammatory cytokines. We identified novel combinations of immunomodulatory mAbs endowed with more potent anti-cancer activity on TNBC and lower cardiotoxic side effects than the combination of atezolizumab and ipilimumab.

HDAC Inhibition to Prime Immune Checkpoint Inhibitors

Immunotherapy has made a breakthrough in medical oncology with the approval of several immune checkpoint inhibitors in clinical routine, improving overall survival of advanced cancer patients with refractory disease. However only a minority of patients experience a durable response with these agents, which has led to the development of combination strategies and novel immunotherapy drugs to further counteract tumor immune escape. Epigenetic regulations can be altered in oncogenesis, favoring tumor progression. The development of epidrugs has allowed targeting successfully these altered epigenetic patterns in lymphoma and leukemia patients. It has been recently shown that epigenetic alterations can also play a key role in tumor immune escape. Epidrugs, like HDAC inhibitors, can prime the anti-tumor immune response, therefore constituting interesting partners to develop combination strategies with immunotherapy agents. In this review, we will discuss epigenetic regulations involved in oncogenesis and immune escape and describe the clinical development of combining HDAC inhibitors with immunotherapies.

High IKZF2 Expression in Malignant T cells Promotes Disease Progression in Cutaneous T cell Lymphoma

Cutaneous T cell lymphoma is a generally indolent disease derived from skin-homing mature T cells. However, in advanced stages, CTCL may manifest as aggressive clinical behavior and lead to a poor prognosis. The mechanism of disease progression in CTCL remains unknown. Here, with a large clinical cohort, we identified that IKZF2, an essential transcription factor during T cell development and differentiation, showed stage-dependent overexpression in the malignant T cells in MF lesions. IKZF2 is specifically over-expressed in advanced-stage MF lesions, correlates with poor patient prognosis. Mechanistically, IKZF2 overexpression promotes CTCL progression via inhibiting malignant cell apoptosis and may contribute to tumor immune escape by downregulating MHC-II molecules and up-regulating the production of anti-inflammatory cytokine IL-10 by malignant T cells. These results demonstrate the important role of IKZF2 in high-risk CTCL and pave the way for future targeted therapy.

Liver fibrosis promotes immunity escape but limits the size of liver tumor in a rat orthotopic transplantation model

Liver fibrosis plays a crucial role in promoting tumor immune escape and tumor aggressiveness for liver cancer. However, an interesting phenomenon is that the tumor size of liver cancer patients with liver fibrosis is smaller than that of patients without liver fibrosis. In this study, 16 SD rats were used to establish orthotopic liver tumor transplantation models with Walker-256 cell lines, respectively on the fibrotic liver (n = 8, LF group) and normal liver (n = 8, control group). MRI (magnetic resonance imaging) was used to monitor the size of the tumors. All rats were executed at the third week after modeling, and the immunohistochemical staining was used to reflect the changes in the tumor microenvironment. The results showed that, compared to the control group, the PD-L1 (programmed cell death protein receptor-L1) expression was higher, and the neutrophil infiltration increased while the effector (CD8+) T cell infiltration decreased in the LF group. Additionally, the expression of MMP-9 (matrix metalloproteinase-9) of tumor tissue in the LF group increased. Three weeks after modeling, the size of tumors in the LF group was significantly smaller than that in the control group (382.47 ± 195.06 mm3 vs. 1736.21 ± 657.25 mm3, P < 0.001). Taken together, we concluded that liver fibrosis facilitated tumor immunity escape but limited the expansion of tumor size.