Novel prognostic model predicts overall survival in colon cancer based on RNA splicing regulation gene expression.

Colon cancer is the third most common cancer and the second leading cause of cancer-related death worldwide. Dysregulated RNA splicing factors have been reported to be associated with tumorigenesis and development in colon cancer. In this study, we interrogated clinical and RNA expression data of colon cancer patients from The Cancer Genome Atlas (TCGA) dataset and the Gene Expression Omnibus (GEO) database. Genes regulating RNA splicing correlated with survival in colon cancer were identified and a risk score model was constructed using Cox regression analyses. In the risk model, RNA splicing factor peroxisome proliferator-activated receptor-γ coactivator-1α (PPARGC1) is correlated with a good survival outcome, whereas Cdc2-like kinase 1(CLK1), CLK2, and A-kinase anchor protein 8-like (AKAP8L) with a bad survival outcome. The risk model has a good performance for clinical prognostic prediction both in the TCGA cohort and the other two validation cohorts. In the tumor microenvironment (TME) analysis, the immune score was higher in the low-risk group, and TME-related pathway gene expression was also higher in low-risk group. We further verified the mRNA and protein expression levels of these four genes in the adjacent nontumor, tumor, and liver metastasis tissues of colon cancer patients, which were consistent with bioinformatics analysis. In addition, knockdown of AKAP8L can suppress the proliferation and migration of colon cancer cells. Animal studies have also shown that AKAP8L knockdown can inhibit tumor growth in colon cancer in vivo. We established a prognostic risk model for colon cancer based on genes related to RNA splicing regulation and uncovered the role of AKAP8L in promoting colon cancer progression.

High AKAP8L expression predicts poor prognosis in esophageal squamous cell carcinoma.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is a severe disease with high mortality, and is associated with poor prognosis and frequent lymphatic metastasis. Therefore, prognostic indicators for ESCC are urgently needed. A-kinase anchor-protein 8-like (AKAP8L) is a member of the A kinase anchor-protein (AKAPs) family and is overexpressed in many cancers. However, the role of AKAP8L in ESCC remains unclear. The aim of this study is to investigate the expression patterns and prognostic value of AKAP8L in ESCC. METHODS: The mRNA expression of AKAP8L was analyzed from the dataset of The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). Immunohistochemistry was applied to detect the AKAP8L expression in tissue microarray. Pearson's chi-square test was carried out for the correlation analysis of clinicopathological features and AKAP8L expression. The prognostic significance of clinicopathological features and AKAP8L expression was determined by univariate and multivariate Cox hazard models. Kaplan-Meier survival curve was used for survival analysis. RESULTS: We found that the mRNA level of AKAP8L was higher in tumor tissues than in adjacent tissues in TCGA and GEO dataset. High AKAP8L expression was associated with poor overall survival (OS) in ESCC patients (p = 0.0039). Besides, AKAP8L expression was highly expressed in patients with lymph node metastasis detected by ESCC tissue microarray (p = 0.0014). The comparison of the different clinicopathological features of ESCC between high and low AKAP8L expression groups revealed that high AKAP8L expression was related to lymph node stage (p = 0.041). Kaplan-Meier survival analysis revealed that high AKAP8L expression indicates an unfavorable progression-free survival (PFS) and OS in ESCC patients (p < 0.0001). Univariate and multivariate analyses confirmed that AKAP8L was an independent prognostic factor for PFS and OS in ESCC (p = 0.003 and p < 0.0001). CONCLUSIONS: In conclusion, this study demonstrated that high expression of AKAP8L is associated with poor prognosis of ESCC and can be considered an independent risk factor for ESCC.

HIF-1α inhibition promotes the efficacy of immune checkpoint blockade in the treatment of non-small cell lung cancer.

The response to immune checkpoint inhibitors (ICIs) monotherapy remains unsatisfactory in patients with NSCLC. Thus, combining ICIs with other potential modalities is of great significance to enhance the response of single drug alone. Here, we identified that HIF-1α inhibition was capable of promoting anti-tumor immunity in NSCLC. We applied NSCLC cell lines and mouse models to evaluate the synergy of combined HIF-1α inhibition and PD-1 blockade on tumor growth and the function of tumor infiltrating lymphocytes (TILs). Public datasets were utilized to investigate patients' prognosis based on expressions of HIF-1α and LOXL2 as well as EMT-associated markers and CD8+ TILs. Moreover, we explored the correlation between HIF-1α and LOXL2 levels and CD8+ TILs in tumor samples from patients with NSCLC by immunohistochemistry, as well as their association to patients' survival. In vitro, PX-478, an HIF-1α inhibitor, promoted tumor cell apoptosis induced by T cells when combined with ICIs. Furthermore, mice treated with PX-478 and anti-PD-1 antibodies exhibited a marked delay in tumor growth and prolonged survival, which correlated with increased TILs and granzyme B secretion. Besides, patients with high HIF-1α expression exhibited high levels of EMT-related markers and low TILs, indicating an immunosuppressive phenotype. Mechanistically, we observed that HIF-1α inhibition suppressed the EMT phenotypes induced by hypoxia and further alleviated tumor immunosuppression, which was related to blockage of HIF-1α/LOXL2 signaling pathway. In summary, we identified that HIF-1α inhibition could synergize with anti-PD-1 to impair tumor growth in vitro and in vivo. Our data suggest that HIF-1α inhibitors represent a promising treatment to enhance anti-tumor immunity and provide preclinical rationale to evaluate the combination of ICIs with HIF-1α inhibition clinically in NSCLC.

Gemcitabine and APG-1252, a novel small molecule inhibitor of BCL-2/BCL-XL, display a synergistic antitumor effect in nasopharyngeal carcinoma through the JAK-2/STAT3/MCL-1 signaling pathway.

Advanced nasopharyngeal carcinoma (NPC) has a poor prognosis, with an unfavorable response to palliative chemotherapy. Unfortunately, there are few effective therapeutic regimens. Therefore, we require novel treatment strategies with enhanced efficacy. The present study aimed to investigate the antitumor efficacy of APG-1252-M1, a dual inhibitor of BCL-2/BCL-XL, as a single agent and combined with gemcitabine. We applied various apoptotic assays and used subcutaneous transplanted NPC model to assess the in vitro and in vivo antitumor activity. Moreover, phospho-tyrosine kinase array was used to investigate the combined therapy's potential synergistic mechanism. In addition, further validation was performed using immunohistochemistry and western blotting. In vitro, we observed that APG-1252-M1 had moderate antitumor activity toward NPC cells; however, it markedly improved gemcitabine's ability to promote NPC cell apoptosis and suppress invasion, migration, and proliferation. Specifically, APG-1252 plus gemcitabine exhibited even remarkable antitumor activity in vivo. Mechanistically, the drug combination synergistically suppressed NPC by activating caspase-dependent pathways, blocking the phospho (p)-JAK-2/STAT3/MCL-1 signaling pathway, and inhibiting epithelial-mesenchymal transition. In conclusion, the results indicated that the combination of APG-1252 and gemcitabine has synergistic anticancer activities against NPC, providing a promising treatment modality for patients with NPC.