Serine protease PRSS56, a novel cancer-testis antigen activated by DNA hypomethylation, promotes colorectal and gastric cancer progression via PI3K/AKT axis

ACTL8 Promotes the Progression of Gastric Cancer Through PI3K/AKT/mTOR Signaling Pathway

BACKGROUND

Actin-like protein 8 (ACTL8) significantly correlates with tumor growth and prognosis across various cancer types. Nevertheless, the potential relationship between ACTL8 and gastric cancer (GC) remains uncertain.

OBJECTIVE

This study aimed to elucidate the role of ACTL8 in human GC cells and to explore its mechanism.

METHODS

Bioinformatics analysis tools, such as GEPIA2, Kaplan-Meier, and STRING, were utilized for a comprehensive investigation of the characteristics and functional roles of ACTL8 in GC, including differential expression, prognostic value, and related signaling pathways. Subsequently, gene expression analyses, cell function assays, and signaling pathway experiments were conducted to verify key findings.

RESULTS

Bioinformatics analysis showed that ACTL8 was significantly elevated in GC and closely associated with poor prognosis. Gene expression experiments confirmed the bioinformatics results. Furthermore, ACTL8 knockdown markedly reduced GC cell proliferation and inhibited migration and invasion. Mechanistically, a significant increase in the phosphorylation levels of signaling proteins was observed in GC cells following ACTL8 overexpression, and PI3K/Akt/mTOR pathway inhibitors could reverse this effect.

CONCLUSION

ACTL8 expression is significantly upregulated in GC cells and is closely correlated with poor patient prognosis. Further mechanistic studies revealed that ACTL8 may promote GC cell migration and proliferation through activation of the PI3K/Akt/mTOR signaling pathway. Consequently, ACTL8 emerges as a promising therapeutic target for GC.

A new high-throughput screening methodology for the discovery of cancer-testis antigen using multi-omics data

BACKGROUND

Cancer/testis antigens (CTAs), also known as tumor-specific antigens (TSAs) are specifically expressed in cancer cells and exhibit high immunogenicity, making them promising targets for immunotherapy and cancer vaccines.

METHODS

A new integrated high-throughput screening methodology for CTAs was proposed in this study through combining DNA methylation and RNA sequencing data. Briefly, the genes with increased transcript level and decreased DNA methylation were identified by multi-omics analysis. RNA sequencing studies in cell lines exposed to DNA methyltransferase (DNMT) inhibitors were performed to validate the inherent causal relationship between DNA hypomethylation and gene expression upregulation.

RESULTS

We proposed a new integrated high-throughput screening methodology for identification of CTAs using multi-omics analysis. In addition, we tested the feasibility of this method using gastric cancer (GC) as an example. In GC, we identified over 2000 primary candidate CTAs and ultimately identified 20 CTAs with significant tissue-specificity, including a testis-specific serine protease TESSP1/PRSS41. Integrated analysis confirmed that PRSS41 expression was reactivated in gastrointestinal cancers by promoter DNA hypomethylation at the CpG site (cg08104780). Additionally, DNA hypomethylation of PRSS41 predicted a poor prognosis in GC.

CONCLUSION

We propose a new high-throughput screening method for the identification of CTAs in cancer and validate its effectiveness. Our work emphasizes that serine protease PRSS41 is a novel TSA that is reactivated in GC due to promoter DNA hypomethylation.

HTRA1 promotes EMT through the HDAC6/Ac-α-tubulin pathway in human GBM cells

BACKGROUND

The infiltrative nature of human gliomas renders complete surgical removal of tumors futile. Thus, illuminating mechanisms of their infiltrative properties may improve therapies and outcomes of glioma patients.

METHODS

Comprehensive bioinformatic analyses of PRSS family were undertaken. Transfection of HTRA1 siRNAs was used to suppress HTRA1 expression. CCK-8, EdU, and colony formation assay were employed to assess cell viability, and cell migration/invasion was detected by transwell, wound healing, and 3D tumor spheroid invasion assays. Immunoprecipitation was applied to study the mechanism that HTRA1 affected cell migration. In addition, in situ xenograft tumor model was employed to explore the role of HTRA1 in glioma growth in vivo.

RESULTS

HTRA1 knockdown could lead to suppression of cell viability, migration and invasion, as well as increased apoptosis. Immunoprecipitation results indicates HTRA1 might facilitate combination between HDAC6 and α-tubulin to enhance cell migration by decreasing α-tubulin acetylation. Besides, HTRA1 knockdown inhibited the growth of xenografts derived from orthotopic implantation of GBM cells and prolonged the survival time of tumor-bearing mice.

CONCLUSION

Our results indicate that HTRA1 promotes the proliferation and migration of GBM cells in vitro and in vivo, and thus may be a potential target for treatment in gliomas.

Fibromodulin overexpression drives oral squamous cell carcinoma via activating downstream EGFR signaling

Accumulating evidence has shown that fibromodulin (FMOD) plays a pivotal role in tumorigenesis and metastasis. However, the biological function of FMOD in oral squamous cell carcinoma (OSCC) remains largely unclear to date. In this study, we confirmed that FMOD was overexpressed and showed a significant association with malignant progression and lymph node metastasis in OSCC. Depletion of FMOD inhibited OSCC proliferation and metastasis in vitro and in vivo. RNA sequencing, western blotting, and rescue assays verified that FMOD exerted oncogenic roles in OSCC via activation of EGFR signaling. In addition, FMOD was proved to be a putative target gene of miR-338-3p. Taken together, FMOD overexpression due to the reduced level of miR-338-3p promotes OSCC by activating EGFR signaling. Our findings provide direct evidence that targeting FMOD could be a promising therapeutic strategy for OSCC patients.