FNDC4 acts as an extracellular factor to promote the invasiveness of hepatocellular carcinoma partly via the PI3K/Akt signalling pathway

Mechanisms Underlying the Rarity of Skeletal Muscle Cancers

Skeletal muscle (SKM), despite comprising ~40% of body mass, rarely manifests cancer. This review explores the mechanisms that help to explain this rarity, including unique SKM architecture and function, which prohibits the development of new cancer as well as negates potential metastasis to SKM. SKM also presents a unique immune environment that may magnify the anti-tumorigenic effect. Moreover, the SKM microenvironment manifests characteristics such as decreased extracellular matrix stiffness and altered lactic acid, pH, and oxygen levels that may interfere with tumor development. SKM also secretes anti-tumorigenic myokines and other molecules. Collectively, these mechanisms help account for the rarity of SKM cancer.

Expression and prognosis analyses of the fibronectin type-III domain-containing (FNDC) protein family in human cancers: A Review

Despite advancements in early detection and treatment, cancer continues to pose a threat to human health and is the leading cause of death worldwide. According to recent research, the fibronectin type-III domain-containing (FNDC) protein family has been implicated in several different human disorders. However, little is known regarding their expression and prognostic significance in most human malignancies. We carried out a thorough cancer vs. normal expression study using the Oncomine and Tumor Immune Estimation Resource (TIMER) databases, as well as a prognostic evaluation using the Kaplan-Meier (KM) plotter and PrognoScan databases. Oncomine revealed that the mRNA expression levels of FNDC1, FNDC3A, and FNDC3B were higher in most malignancies than in normal tissues, but the mRNA expression levels of FNDC4, FNDC5, FNDC7, and FNDC8 were downregulated in most cancers when compared with normal tissues. In survival analyses based on KM Plotter and PrognoScan, all members of the FNDC family displayed significant correlations with survival outcomes in breast, gastric, and ovarian cancers. Furthermore, the whole FNDC family, except for FNDC7 and FNDC8, was found to have substantial predictive effects in lung adenocarcinoma, but not in squamous cell lung cancer. In addition, potential connections between several FNDC family members and survival results in liver and colorectal malignancies were discovered in this study. One or more members of the FNDC family demonstrated statistically significant differences in expression between cancer and normal tissues, suggesting that they could be used as prognostic biomarkers for specific cancers.

Analysis and identification of the necroptosis landscape on therapy and prognosis in bladder cancer

Bladder cancer (BLCA) is one of the most common malignant tumors of the urinary system, but the current therapeutic strategy based on chemotherapy and immune checkpoint inhibitor (ICI) therapy cannot meet the treatment needs, mainly owing to the endogenous or acquired apoptotic resistance of cancer cells. Targeting necroptosis provides a novel strategy for chemotherapy and targeted drugs and improves the efficacy of ICIs because of strong immunogenicity of necroptosis. Therefore, we systemically analyzed the necroptosis landscape on therapy and prognosis in BLCA. We first divided BLCA patients from The Cancer Genome Atlas (TCGA) database into two necroptosis-related clusters (C1 and C2). Necroptosis C2 showed a significantly better prognosis than C1, and the differential genes of C2 and C1 were mainly related to the immune response according to GO and KEGG analyses. Next, we constructed a novel necroptosis-related gene (NRG) signature consisting of SIRT6, FASN, GNLY, FNDC4, SRC, ANXA1, AIM2, and IKBKB to predict the survival of TCGA-BLCA cohort, and the accuracy of the NRG score was also verified by external datasets. In addition, a nomogram combining NRG score and several clinicopathological features was established to more accurately and conveniently predict the BLCA patient’s survival. We also found that the NRG score was significantly related to the infiltration levels of CD8 T cells, NK cells, and iDC cells, the gene expression of CTLA4, PD-1, TIGIT, and LAG3 of TME, and the sensitivity to chemotherapy and targeted agents in BLCA patients. In conclusion, the NRG score has an excellent performance in evaluating the prognosis, clinicopathologic features, tumor microenvironment (TME), and therapeutic sensitivity of BLCA patients, which could be utilized as a guide for chemotherapy, ICI therapy, and combination therapy.

Correlation of the prognostic value of FNDC4 in glioblastoma with macrophage polarization

BACKGROUND

Glioblastoma is among the most malignant tumors in the central nervous system and characterized by strong invasion and poor prognosis. Fibronectin type III domain-containing 4 (FNDC4) plays various important roles in the human body, including participating in cellular metabolism and inflammatory responses to cardiovascular diseases, influencing immune cells, and exerting anti-inflammatory effects; however, the role of FNDC4 in glioblastoma has not been reported.

METHODS

In this study, bioinformatics databases, including TCGA, CGGA, GTEx, and TIMER, were used to analyze the differential expression of FNDC4 genes and cell survival, in addition to investigating its relationship with immune cell infiltration. Additionally, we overexpressed FNDC4 in glioblastoma cell lines U87 and U251 by lentiviral transfection and detected changes in proliferation, cell cycle progression, and apoptosis. Following collection of monocytes from the peripheral blood of healthy individuals and transformation into M0 macrophages, we performed flow cytometry to detect the polarizing effect of exogenous FNDC4, as well as the effect of FNDC4-overexpressing glioblastoma cells on macrophage polarization in a co-culture system.

RESULTS

We identified that significantly higher FNDC4 expression in glioblastoma tissue relative to normal brain tissue was associated with worse prognosis. Moreover, we found that FNDC4 overexpression in U87 and U251 cells resulted in increased proliferation and affected the S phase of tumor cells, whereas cell apoptosis remained unchanged. Furthermore, exogenous FNDC4 inhibited the M1 polarization of M0 macrophages without affecting M2 polarization; this was also observed in glioblastoma cells overexpressing FNDC4.

CONCLUSIONS

FNDC4 expression is elevated in glioblastoma, closely associated with poor prognosis, and promoted the proliferation of glioblastoma cells, affected the S phase of tumor cells while inhibiting macrophage polarization.

Prognostic value of transcriptional expression of fibronectin type III domain-containing 4 (FNDC4) in head and neck carcinoma patients treated with chemoradiotherapy

Purpose

FNDC4 gene encodes the fibronectin type III domain-containing 4 protein. Elevated expression of FNDC4 has been associated with poor prognosis in several types of cancer. There are no studies that have evaluated the prognostic capacity of FNDC4 in patients with head and neck cancer (HNSCC). The aim of our study was to analyze the relationship between the transcriptional expression of FNDC4 and prognosis in HNSCC patients.

Methods

We determined the transcriptional expression of FNDC4 in 67 patients with advanced-stage HNSCC (III–IV) treated with chemoradiotherapy. The FNDC4 expression was categorized according to the disease-specific survival with a recursive partitioning analysis.

Results

There were significant differences in disease-specific survival as a function of the level of FNDC4 transcriptional expression. The 5-year disease-specific survival for patients with high FNDC4 expression (n = 44, 65.7%) was 32.9% (95% CI: 16.5–49.3%), and for patients with low expression (n = 23, 34.3%) it was 85.4% (95% CI: 70.2–100%) (P = 0.0001). Patients with a high FNDC4 expression had poorer local (P = 0.097), regional (P = 0.008), and distant (0.034) recurrence-free survival. The results of a multivariate analysis showed that patients with a high FNDC4 expression had a 6.15-fold increased risk of death as a consequence of the HNSCC (95% CI: 1.71–22.06).

Conclusion

FNCF4 transcriptional expression was significantly related to the disease-specific survival of HNSCC patients treated with chemoradiotherapy. Patients with elevated FNDC4 expression had a significant decrease in disease-specific survival.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12094-022-02870-3.

A hybrid feature selection algorithm and its application in bioinformatics

Feature selection is an independent technology for high-dimensional datasets that has been widely applied in a variety of fields. With the vast expansion of information, such as bioinformatics data, there has been an urgent need to investigate more effective and accurate methods involving feature selection in recent decades. Here, we proposed the hybrid MMPSO method, by combining the feature ranking method and the heuristic search method, to obtain an optimal subset that can be used for higher classification accuracy. In this study, ten datasets obtained from the UCI Machine Learning Repository were analyzed to demonstrate the superiority of our method. The MMPSO algorithm outperformed other algorithms in terms of classification accuracy while utilizing the same number of features. Then we applied the method to a biological dataset containing gene expression information about liver hepatocellular carcinoma (LIHC) samples obtained from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx). On the basis of the MMPSO algorithm, we identified a 18-gene signature that performed well in distinguishing normal samples from tumours. Nine of the 18 differentially expressed genes were significantly up-regulated in LIHC tumour samples, and the area under curves (AUC) of the combination seven genes (ADRA2B, ERAP2, NPC1L1, PLVAP, POMC, PYROXD2, TRIM29) in classifying tumours with normal samples was greater than 0.99. Six genes (ADRA2B, PYROXD2, CACHD1, FKBP1B, PRKD1 and RPL7AP6) were significantly correlated with survival time. The MMPSO algorithm can be used to effectively extract features from a high-dimensional dataset, which will provide new clues for identifying biomarkers or therapeutic targets from biological data and more perspectives in tumor research.

FNDC4 acts as an extracellular factor to promote the invasiveness of hepatocellular carcinoma partly via the PI3K/Akt signalling pathway

FNDC4 is highly homologous to the exercise‐associated myokine FNDC5/irisin, which is highly expressed and promotes the invasion and metastasis of HCC cells. However, the function of FNDC4 remains unknown. Here, we report that FNDC4, an extracellular factor, plays important roles in the invasion and metastasis of HCC. We found that high FNDC4 expression is associated with poor survival in HCC patients and FNDC4 promotes the migration and invasion of HCC cells. Mechanistically, we found that FNDC4 is related to the PI3K/Akt signalling pathway to a certain extent. Specifically, the extracellular domain of FNDC4 acts as an extracellular factor to promote Akt phosphorylation levels in this pathway. These findings reveal that FNDC4 promotes the invasion and metastasis of HCC partly via the PI3K/Akt signalling pathway.