Expression and function of Siglec-15 in RLPS and its correlation with PD-L1: Bioinformatics Analysis and Clinicopathological Evidence.

Purpose: Retroperitoneal liposarcoma (RLPS) is a rare malignancy without effective treatment. Since current treatment for unresectable RLPS is unsatisfactory, immunotherapy and targeted therapy are urgently needed. Siglec-15 is a transmembrane protein highly homologous to PD-L1 and is involved in tumor immune escape. The biological function of Siglec-15 in RLPS, its prognostic relevance and its relationship with PD-L1 need to be further clarified. In this study, we aimed to explore the biological function of Siglec-15 in sarcomas through bioinformatics analysis, and we also evaluated Siglec-15 and PD-L1 expression in RLPS samples. The relationship between the expression of Siglec-15 and PD-L1 and their clinicopathological relevance and prognostic value were also investigated in clinical RLPS patients. Methods: The RNA sequencing data of 259 sarcoma cases and 48 RLPS cases from TCGA were used to analyze the Siglec-15 expression and the differentially expressed genes (DEG) related with Siglec-15 expression. In addition, DEGs were subsequently analyzed through the gene ontology (GO)/ Kyoto Encyclopedia of Genes and Genomes (KEGG) and protein-protein interaction (PPI) network. Tumor specimens were obtained from 91 RLPS patients of our sarcoma center, and Siglec-15 and PD-L1 expression were evaluated using immunohistochemistry. The correlation between the expression level of these two markers as well as their correlation with clinicopathological factors and prognosis of RLPS patients was also assessed. Results: GEPIA analysis showed that the high expression of Siglec-15 was associated with poor sarcoma OS (P=0.034). A total of 682 differential genes were identified between the high and low expression groups of Siglec-15 in RLPS. Enrichment analysis of the KEGG pathway showed that Siglec-15 was related to the Hippo signaling pathway and the neuroactive ligand-receptor interaction. GO annotation analysis showed that the expression of Siglec-15 may thus be able to affect serine hydrolase activity, alongside signal receptor activator activity. The top 5 genes with the largest number of connection points are APOA1, F2, AHSG, AMBP, SERPINC1. In subsequent studies, we used 91 liposarcoma samples from our center for verification. Siglec-15 was expressed in 84.6% of RLPS cases, whereas PD-L1 was expressed in 17.6% of RLPS cases. A negative correlation was observed between Siglec-15 and PD-L1 expression (P=0.020). In this group of RLPS patients, high Siglec-15 expression was correlated with poorer disease-free survival (DFS) (P=0.021), and it was an independent predictor of DFS (hazard ratio: 2.298; 95% confidence interval: 1.154-4.576; P=0.018). However, we did not find a correlation between PD-L1 expression and overall survival or DFS in RLPS patients. Conclusion: The DEG and signaling pathways identified in the study could provide a preliminary understanding of the underlying molecular mechanisms of Siglec-15 in the development and progression of RLPS. High expression of Siglec-15 was a negative independent predictive factor for DFS of RLPS. The negative relationship between Siglec-15 and PD-L1 expression suggested that the Siglec-15 pathway might be an important supplement to PD-L1 treatment.

Anti-Tumor Effect of Apatinib and Relevant Mechanisms in Liposarcoma.

BACKGROUND: Primary retroperitoneal liposarcomas (RLPSs) are rare heterogeneous tumors for which there are few effective therapies. Certain anti-angiogenic tyrosine kinase inhibitors have demonstrated efficacy against various solid tumors. The aims of this study were to investigate the effect of Apatinib against retroperitoneal liposarcoma cells and its underlying mechanism and to explore the anti-tumor efficacy of a combination of Apatinib and Epirubicin. METHODS: CD34 immunohistochemical staining was used to measure microvessel density (MVD) in 89 retroperitoneal liposarcoma tissues. We used CCK-8 cell proliferation, clone formation, Transwell migration, invasion assays and flow cytometry to evaluate the effects of Apatinib alone and the combination of Apatinib and Epirubicin on liposarcoma cells. High-throughput RNA sequencing and western-blotting was used to identify key differentially expressed genes (DEGs) in SW872 cell line after application of Apatinib. Murine patient-derived tumor xenograft (PDX) was established to assess the efficacy and safety of Apatinib monotherapy and the combination of Apatinib and Epirubicin in RLPS. RESULTS: The microvessel density (MVD) varied widely among retroperitoneal liposarcoma tissues. Compared with the low-MVD group, the high-MVD group had poorer overall survival. Apatinib inhibited the liposarcoma cell proliferation, invasion and migration, increased the proportion of apoptosis, and induced G1 phase arrest. In addition, the combination of Apatinib and Epirubicin enhanced the foregoing inhibitory effects. High-throughput RNA sequencing showed that Apatinib downregulated the expression of TYMS and RRM2. Western blotting verified that Apatinib downregulated the TYMS/STAT3/PD-L1 pathway and inhibited liposarcoma proliferation by suppressing the RRM2/PI3K/AKT/mTOR pathway. In the murine PDX model of retroperitoneal liposarcoma, Apatinib and its combination with Epirubicin significantly inhibited microvessel formation and repressed tumor growth safely and effectively. CONCLUSIONS: Apatinib and its combination with Epirubicin showed strong efficacy against liposarcoma both in vitro and in vivo. Apatinib might inhibit liposarcoma cell proliferation through the RRM2/PI3K/AKT/mTOR signaling pathway and downregulate PD-L1 via the TYMS/STAT3 signaling pathway.

Dexamethasone inhibits pancreatic tumor growth in preclinical models: Involvement of activating glucocorticoid receptor.

Glucocorticoid receptor (GR) modulates extensive biological and pathological processes including tumor progression through diverse mechanisms. The regulatory effects of dexamethasone (DEX), a synthetic glucocorticoid, as well as its interaction with GR have been recognized beyond hematologic cancers. In the present study, we investigated the anti-cancer efficacy of DEX and the correlation with GR in pancreatic cancer, a most aggressive malignancy threatening human health. The differential levels of GR expression were examined in two human pancreatic cancer cell lines, PANC-1 and SW1990, as well as in xenografts and patient tumor tissues. DEX significantly inhibited colony formation, migration, and tumor growth of PANC-1 cells expressing abundant GR. The underlying mechanisms involved suppression of nuclear factor κB (NF-κB) phosphorylation and down-regulation of epithelial-to-mesenchymal transition (EMT), interleukin 6 (IL-6) and vascular endothelial growth factor (VEGF). The anti-cancer effects of DEX were partially reversed by GR silencing or combinational administration of GR antagonist, RU486. The dose-dependent efficacy of DEX in tumor growth inhibition was also demonstrated in a GR-positive patient-derived xenograft model along with safety in mice. DEX was less potent, however, in SW1990 cells with poor GR expression. Our findings suggest that DEX effectively inhibits pancreatic tumor growth partially through GR activation. The potential correlation between GR expression and anti-cancer efficacy of DEX may have some clinical implications.

Expressions of insulin-like growth factor receptor-1 and cezanne-1 in lung adenocarcinoma.

IGF1R (insulin-like growth factor receptor-1) was confirmed to play a significant role in the development of cancer. Cezanne-1 overexpression was considered to be associated with enhancement of EGFR signaling pathway and reduced degeneration of EGFR. There was a close relationship between EGFR and IGFR as previous study showed. Dynamic balance between receptor ubiquitination and deubiquitination was critical in the process of termination of IGF signaling pathway. So we conducted an IHC staining to initially prove the correlation. Cezanne-1 and IGF1R expressions were evaluated in 103 patients with lung adenocarcinoma using immunohistochemical (IHC) analysis. The relationship between expressions of cezanne-1 and IGF1R were analyzed by χ2 test. Kaplan-Meier method was used to generate the survival curve, and the statistical difference was calculated by log-rank test. We also used data in R2 system to verify the relationship between IGF1R and cezanne-1. R2 system showed there was a close correlation between IGF1R and cezanne-1. Positive expression of cezanne-1 was detected in 64.1% patients. A significant association was shown between cezanne-1 and IGF1R expression (p < 0.001). Multivariate analysis confirmed that both cezanne-1 and IGF1R expressions were independent prognostic factors for OS. (HR 2.96, 95% CI 1.090-8.060, p = 0.033; HR 2.273, 95% CI 1.016-5.085, p = 0.046, respectively). Our findings indicated both cezanne-1 and IGF1R expressions were negative independent predictive factors for the prognosis of lung adenocarcinoma, respectively. There was a close positive interrelationship between cezanne-1 and IGF1R expression.

Sublobectomy versus lobectomy for stage I non-small cell lung cancer in the elderly.

OBJECTIVE: The aim of our study was to compare the operative characteristics and long term survival for elderly patients with stage I non-small cell lung cancer (NSCLC) who underwent sublobectomy versus lobectomy. METHODS: We identified 245 consecutive elderly patients (≥65y) with pathologic stage I NSCLC who underwent lobectomy or sublobectomy at our institution between 2006 and 2012, and assessed the operative characteristics, recurrence, and survival differences between these approaches. RESULTS: A total of 39 patients underwent sublobectomy and 206 patients had lobectomy. There were significantly more COPD (p = 0.046) and low percent of predicted FEV1 (p = 0.034) in sublobectomy patients compared to the lobectomy group. Sublobectomy patients had significantly shorter operating time (p = 0.001), less blood loss (p = 0.000), and trended toward fewer chest tube days (p = 0.001) and shorter hospital length of stay (p = 0.030). The 1-, 3-, and 5-year survival rates in patients with lobectomy were 91.3, 77.7, and 64.1%, respectively, and has no significantly difference with those underwent sublobectomy (87.2, 74.4, and 61.5%, respectively, p = 0.623). Subgroups survival analysis showed no significant difference in the OS and DFS for patients with T < 2 cm or %FEV1<80%, but survival after sublobectomy was worse if performed on patients with larger tumours (T ≥ 2 cm) or relatively strong lung function (%FEV1≥80%). CONCLUSION: We concluded that sublobectomy might achieve similar survival rates when compared with lobectomy in elderly stage I NSCLC patients, especially for patients with low %FEV1 and stage IA tumours less than 2 cm in diameter.

Adverse Events and Efficacy of Cixutumumab in Phase II Clinical Trials: A systematic Review and Meta-Analysis.

BACKGROUND AND OBJECTIVES: Cixutumumab is a monoclonal antibody targeting insulin-like growth factor 1 receptor (IGF1R). We sought to evaluate the efficacy of cixutumumab in the treatment of cancer, and to comprehensively assess the associated adverse events in phase II clinical trials. METHODS: Data were collected from PubMed, Embase, and Clinicaltrials.gov. The improvement on progression-free survival (PFS) was evaluated by hazard ratio (HR) and 95% confidence intervals (95% CIs). We also carried a meta-analysis to comprehensively evaluate the incidence of adverse events. RESULTS: The adverse events that were mentioned most frequently were hyperglycemia, anemia, nausea, fatigue, and thrombocytopenia. The most frequent adverse events were hyponatremia (40.28%), fatigue (35.18%), and skin rash (35.11%). Results showed that cixutumumab treatments did not benefit PFS (HR 1.03, 95% CI 0.83-1.26, p = 0.979). The complete response (CR) was rarely seen in phase II trials. CONCLUSIONS: Cixutumumab was well tolerated when used alone and in combination therapies, but its antitumor activity was low in the existing phase II clinical trials. An acceptable incidence of adverse effects supports further investigation of this drug, provided that it shows antitumor activity in combination with other drugs.