Signature identification of relapse-related overall survival of early lung adenocarcinoma after radical surgery

Edge-based relative entropy as a sensitive indicator of critical transitions in biological systems

BACKGROUND

Disease progression in biosystems is not always a steady process but is occasionally abrupt. It is important but challenging to signal critical transitions in complex biosystems.

METHODS

In this study, based on the theoretical framework of dynamic network biomarkers (DNBs), we propose a model-free method, edge-based relative entropy (ERE), to identify temporal key biomolecular associations/networks that may serve as DNBs and detect early-warning signals of the drastic state transition during disease progression in complex biological systems. Specifically, by combining gene‒gene interaction (edge) information with the relative entropy, the ERE method converts gene expression values into network entropy values, quantifying the dynamic change in a biomolecular network and indicating the qualitative shift in the system state.

RESULTS

The proposed method was validated using simulated data and real biological datasets of complex diseases. The applications show that for certain diseases, the ERE method helps to reveal so-called "dark genes" that are non-differentially expressed but with high ERE values and of essential importance in both gene regulation and prognosis.

CONCLUSIONS

The proposed method effectively identified the critical transition states of complex diseases at the network level. Our study not only identified the critical transition states of various cancers but also provided two types of new prognostic biomarkers, positive and negative edge biomarkers, for further practical application. The method in this study therefore has great potential in personalized disease diagnosis.

MiRNA-144-5p down-modulates CDCA3 to regulate proliferation and apoptosis of lung adenocarcinoma cells

BACKGROUND

Lung adenocarcinoma (LUAD) belongs to non-small cell lung cancer. In addition to surgical resection, chemotherapy and radiotherapy cause great side effects and low 5-year survival rates. MiRNAs are closely related to cancer development. This study aimed to analyze the molecular mechanism of miRNA-144-5p targeting CDCA3 to inhibit LUAD proliferation.

METHODS

MiRNA and mRNA data were downloaded from TCGA-LUAD dataset for differential expression analysis. TargetScan and miRTarBase databases were adopted to predict the target genes of miRNA, and the signaling pathways involved were analyzed by gene set enrichment analysis. The functions of LUAD cells were analyzed by CCK-8, colony formation assay, stem cell spheroidization assay, and flow cytometry. The expression levels of CDCA3, p53, and cell cycle-associated proteins were evaluated by Western blot.

RESULTS

The expression of miRNA-144-5p was significantly down-regulated in LUAD, but overexpression of it repressed proliferation and spheroidization, and promoted apoptosis of LUAD cells. By bioinformatics prediction and dual-luciferase reporter assay, miRNA-144-5p was validated to target CDCA3, thereby regulating proliferation of LUAD cells. Besides, the results of cell experiments showed that miRNA-144-5p targeting CDCA3 affected cell proliferation and apoptosis in LUAD by regulating cell cycles, and miRNA-144-5p/CDCA3 mediated the p53 signaling pathway to affect the growth of LUAD cells.

SIGNIFICANCE

Through the study of the pathogenesis of miRNA-144-5p regulating LUAD, we can better understand the molecular mechanism underlying LUAD development.

Decreased INPP5B expression predicts poor prognosis in lung adenocarcinoma

Background

Inositol Polyphosphate-5-Phosphatase B (INPP5B), a inositol 5-phosphatase, plays an important role in many biological processes through phosphorylating PI(4,5)P₂ and/or PI(3,4,5)P₃ at the 5-position. Nevertheless, little is known about its function and cellular pathways in tumors. This study aims to investigate the potential role of INPP5B as a diagnostic and prognostic biomarker for lung adenocarcinoma (LUAD), as well as its biological functions and molecular mechanisms in LUAD.

Methods

TCGA, GEO, CTPAC, and HPA datasets were used for differential expression analysis and pathological stratification comparison. The prognostic and diagnostic role of INPP5B was determined by Kaplan–Meier curves, univariate and multivariate Cox regression analysis, and receiver operating characteristics (ROC) curve analyses. The potential mechanism of INPP5B was explored through GO, KEGG, and GSEA enrichment analysis, as well as GeneMANIA and STRING protein–protein interaction (PPI) network. PicTar, PITA, and miRmap databases were used for exploring miRNA targeting INPP5B. In molecular biology experiments, immunohistochemical analyses and Western blot analyses were used to determine protein expression. Co-immunoprecipitation assay was used to detect protein–protein interactions. CCK8 assays and colony formation assays were used for the measurement of cell proliferation. Cell cycle was assessed by PI staining with flow cytometry. Cell migration was performed by Transwell assays and wound healing assays.

Result

INPP5B was decreased in LUAD tissues compared with normal adjacent tissues. And the low expression of INPP5B was associated with late-stage pathological features. In addition, INPP5B was found to be a significant independent prognostic and diagnostic factor for LUAD patients. Hsa-miR-582-5p was predicted as a negative regulator of INPP5B mRNA expression. INPP5B was significantly correlated with the expression of PTEN and the activity of PI3K/AKT signaling pathways, as determined by enrichment analysis and PPI network. In vitro experiments partially confirmed the aforementioned findings. INPP5B could interact directly with PTEN. INPP5B overexpression inhibited LUAD cell proliferation and migration while downregulating the AKT pathway.

Conclusion

Our results demonstrated that INPP5B could inhibit the proliferation and metastasis of LUAD cells. It could serve as a novel diagnostic and prognostic biomarker for LUAD patients.

Trial registration LUAD tissues and corresponding para-cancerous tissues were collected from 10 different LUAD patients at Hangzhou First People’s Hospital. The Ethics Committee of Hangzhou First People’s Hospital has approved this study. (registration number: IIT-20210907-0031-01; registration date: 2021.09.13)

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02609-8.