The expression patterns and prognostic significance of pleckstrin homology-like domain family A (PHLDA) in lung cancer and malignant mesothelioma

Unraveling the kinase code: Role of protein kinase in lung cancer pathogenesis and therapeutic strategies

Lung cancer is a prominent cause of cancer-related deaths globally, prompting exploration into the molecular pathways governing cancer cell signaling. Recent insights highlight the critical role of kinases in carcinogenesis and metastasis, particularly in non-small cell lung cancer (NSCLC), where protein kinases significantly contribute to drug resistance. These diverse enzymes catalyze protein phosphorylation and are implicated in cancer through misregulated expression, amplification, aberrant phosphorylation, mutations, and chromosomal translocations. Amplifications of kinases serve as important diagnostic, prognostic, and predictive biomarkers across various cancers. Notably, the Phosphatidylinositol 3-kinase (PI3K)/AKT pathway is crucial for the survival and proliferation of tumor cells. Novel therapeutic approaches are being explored to precisely target these pathways. Peptide-based therapies offer specificity and reduced toxicity compared to conventional treatments, while gene therapy targets abnormal genetic expressions. Advances in nanotechnology and CRISPR/Cas9 systems enhance gene delivery methods, holding promise for targeting specific molecular pathways in lung cancer treatment and minimizing systemic toxicity.

The Role of PHLDA3 in Cancer Progression and Its Potential as a Therapeutic Target

Pleckstrin homology-like domain family A, member 3 (PHLDA3) is a p53-regulated tumor suppressor protein that suppresses AKT-mediated survival and oncogenic signaling. The PHLDA3 gene has garnered significant attention due to its multifaceted roles in tumorigenesis, metastasis, and invasion. This review explores the complex interactions between PHLDA3 and key cellular processes involved in cancer, emphasizing its regulatory mechanisms and clinical relevance. PHLDA3 has been found to be a critical regulator of metastatic pathways, particularly through its influence on the epithelial-mesenchymal transition (EMT) and in cellular invasion. Its interactions with pivotal signaling pathways, such as the Phosphoinositide 3-kinases/Protein kinase B (PI3K/AKT), p53, and Wnt/β-catenin pathways, highlight its multifunctional roles in various cancer types. Additionally, we discuss the potential of PHLDA3 as both a prognostic biomarker and a therapeutic target, offering new insights into its potential in treating advanced-stage malignancies. This review provides a detailed analysis of the role of PHLDA3 in cancer progression, including metastasis and invasion, underscoring its therapeutic potential.

Expanding on roles of pleckstrin homology-like domain family A member 1 protein

Pleckstrin homology-like domain, family A, member 1 (PHLDA1), one of the three members of PHLDA (1-3) family, has been reported to be expressed in mammalian cells and tissues and play diverse roles in various biological processes such as apoptosis, pyroptosis, and differentiation. Nevertheless, new roles and mechanisms of PHLDA1 action have come to light, with some needing further clarification. The major aim of the publication is to review proapoptotic or antiapoptotic roles of PHLDA1 in cancer, including ample evidence on PHLDA1 role as a tumor suppressor gene or oncogene and its influence on tumor progression. The role of PHLDA1 as a prognostic marker of cancer emerges, as well as its role in drug response and resistance. PHLDA1 involvement in autophagy, endoplasmic reticulum stress, pyroptosis, or differentiation is also scrutinized. It is also important to note that the association of PHLDA1 with miRNA regulation is described. Additionally, the emerging functions of PHLDA1 are indicated, specifically in inflammation and ischemia/reperfusion injury.

Epigenetic modification of PHLDA2 is associated with tumor microenvironment and unfavorable outcome of immune checkpoint inhibitor-based therapies in clear cell renal cell carcinoma

BACKGROUND

A substantial proportion of patients with metastatic clear cell renal cell carcinoma (ccRCC) cannot derive benefit from immune checkpoint inhibitor (ICI) plus anti-angiogenic agent combination therapy, making identification of predictive biomarkers an urgent need. The members of pleckstrin homology-like domain family A (PHLDA) play critical roles in multiple cancers, whereas their roles in ccRCC remain unknown.

METHODS

Transcriptomic, clinical, genetic alteration and DNA methylation data were obtained for integrated analyses from TCGA database. RNA sequencing was performed on 117 primary tumors and 79 normal kidney tissues from our center. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis, gene set enrichment analysis were performed to explore transcriptomic features. Data from three randomized controlled trials (RCT), including CheckMate025, IMmotion151, JAVELIN101, were obtained for validation.

RESULTS

Members of PHLDA family were dysregulated in pan-cancer. Elevated PHLDA2 expression was associated with adverse clinicopathologic parameters and worse prognosis in ccRCC. Aberrant DNA hypomethylation contributed to up-regulation of PHLDA2. An immunosuppressive microenvironment featured by high infiltrates of Tregs and cancer-associated fibroblasts, was observed in ccRCC with higher PHLDA2 expression. Utilizing data from three RCTs, the association of elevated PHLDA2 expression with poor therapeutic efficacy of ICI plus anti-angiogenic combination therapy was confirmed.

CONCLUSIONS

Our study revealed that elevated PHLDA2 expression regulated by DNA hypomethylation was correlated with poor prognosis and immunosuppressive microenvironment, and highlighted the role of PHLDA2 as a robust biomarker for predicting therapeutic efficacy of ICI plus anti-angiogenic agent combination therapy in ccRCC, which expand the dimension of precision medicine.

Multiomics Analysis of the PHLDA Gene Family in Different Cancers and Their Clinical Prognostic Value

The PHLDA (pleckstrin homology-like domain family) gene family is popularly known as a potential biomarker for cancer identification, and members of the PHLDA family have become considered potentially viable targets for cancer treatments. The PHLDA gene family consists of PHLDA1, PHLDA2, and PHLDA3. The predictive significance of PHLDA genes in cancer remains unclear. To determine the role of pleckstrin as a prognostic biomarker in human cancers, we conducted a systematic multiomics investigation. Through various survival analyses, pleckstrin expression was evaluated, and their predictive significance in human tumors was discovered using a variety of online platforms. By analyzing the protein-protein interactions, we also chose a collection of well-known functional protein partners for pleckstrin. Investigations were also carried out on the relationship between pleckstrins and other cancers regarding mutations and copy number alterations. The cumulative impact of pleckstrin and their associated genes on various cancers, Gene Ontology (GO), and pathway analyses were used for their evaluation. Thus, the expression profiles of PHLDA family members and their prognosis in various cancers may be revealed by this study. During this multiomics analysis, we found that among the PHLDA family, PHLDA1 may be a therapeutic target for several cancers, including kidney, colon, and brain cancer, while PHLDA2 can be a therapeutic target for cancers of the colon, esophagus, and pancreas. Additionally, PHLDA3 may be a useful therapeutic target for ovarian, renal, and gastric cancer.

Heat shock protein family A member 8 serving as a co-activator of transcriptional factor ETV4 up-regulates PHLDA2 to promote the growth of liver cancer

Heat shock protein family A member 8 (HSPA8) participates in the folding or degradation of misfolded proteins under stress and plays critical roles in cancer. In this study, we investigated the function of HSPA8 in the development of liver cancer. By analyzing the TCGA transcriptome dataset, we found that HSPA8 was upregulated in 134 clinical liver cancer tissue samples, and positively correlated with poor prognosis. IHC staining showed the nuclear and cytoplasmic localization of HSPA8 in liver cancer cells. Knockdown of HSPA8 resulted in a decrease in the proliferation of HepG2 and Huh-7 cells. ChIP-seq and RNA-seq analysis revealed that HSPA8 bound to the promoter of pleckstrin homology-like domain family A member 2 (PHLDA2) and regulated its expression. The transcription factor ETV4 in HepG2 cells activated PHLDA2 transcription. HSPA8 and ETV4 could interact with each other in the cells and colocalize in the nucleus. From a functional perspective, we demonstrated that HSPA8 upregulated PHDLA2 through the coactivating transcription factor ETV4 to enhance the growth of liver cancer in vitro and in vivo. From a therapeutic perspective, we identified both HSPA8 and PHDLA2 as novel targets in the treatment of HCC. In conclusion, this study demonstrates that HSPA8 serves as a coactivator of ETV4 and upregulates PHLDA2, leading to the growth of HCC, and is a potential therapeutic target in HCC treatment.

Knockdown of PHLDA1 alleviates sepsis-induced acute lung injury by downregulating NLRP3 inflammasome activation

OBJECTIVE

To investigate the regulatory mechanism of pleckstrin homology-like domain, family A, member 1 (PHLDA1) in sepsis-induced acute lung injury (ALI).

METHOD

Mice model of sepsis were established by cecal ligation and puncture (CLP). The expression of PHLDA1 was reduced by injecting short hairpin RNA (shRNA)-PHLDA1 into the tail vein. The levels of PHLDA1, pro-inflammatory cytokines, such as interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), IL-1β, IL-18, super-oxide dismutase (SOD), malondialdehyde (MDA), and glutathione (GSH), molecular mechanism related to pyroptosis, such as caspase 1, adaptor apoptosis-associated speck-like protein containing a CARD (ASC), and gasdermin D (GSDMD)-N, and nucleotide oligomerization domain (NOD)-like receptor family pyrin domain-containing 3 (NLRP3) were tested by Western blot analysis, quantitative real-time polymerase chain reaction, and enzyme-linked-immunosorbent serologic assay. Pathological changes in lung tissues were examined by hematoxylin and eosin staining. Wet-dry weight ratio of lung tissues was observed.

RESULTS

The expression of PHLDA1 was up-regulated in lung tissues from CLP-induced septic mice. Knockdown of PHLDA1 could reduce lung injury and wet-dry weight ratio in mice with sepsis-induced ALI. Moreover, silencing of PHLDA1 decreased the expressions of IL-1β, TNF-α, IL-18, IL-6, and MDA but increased SOD and GSH expressions in CLP-induced septic mice. The expressions of NLRP3, GSDMD-N, ASC, and caspase 1 were decreased by PHLDA1 silencing.

CONCLUSION

Knockdown of PHLDA1 inhibited lung inflammation and pyroptosis in mice with sepsis-induced ALI by down-regulating NLRP3.

Knockdown of PHLDA2 promotes apoptosis and autophagy of glioma cells through the AKT/mTOR pathway

Pleckstrin homology like domain family A member 2 (PHLDA2) is an imprinted gene expressed in placenta and has been shown to be associated with tumor progression. However, the effect of PHLDA2 on glioma cell growth has not been reported yet. Data based on TCGA database showed that PHLDA2 was up-regulated in glioma tissues. Moreover, PHLDA2 was also elevated in glioma cells. Functional assays showed that siRNA-mediated knockdown of PHLDA2 reduced cell viability of glioma cells and suppressed the cell proliferation. Cell apoptosis of glioma cells was promoted by silencing of PHLDA2 with increased Bax and decreased Bcl-2. Silencing of PHLDA2 reduced protein expression of p62, enhanced LC3 and Beclin1 to promote autophagy. Phosphorylated AKT and mTOR were down-regulated in glioma cells by interference of PHLDA2. In conclusion, downregulation of PHLDA2 inhibited glioma cell proliferation, and promoted cell apoptosis and autophagy through inactivation of AKT/mTOR signaling.

Immune Characteristics Analysis and Transcriptional Regulation Prediction Based on Gene Signatures of Chronic Obstructive Pulmonary Disease

Purpose

The variation in inflammation in chronic obstructive pulmonary disease (COPD) between individuals is genetically determined. This study aimed to identify gene signatures of COPD through bioinformatics analysis based on multiple gene sets and explore their immune characteristics and transcriptional regulation mechanisms.

Methods

Data from four microarrays were downloaded from the Gene Expression Omnibus database to screen differentially expressed genes (DEGs) between COPD patients and controls. Weighted gene co-expression network analysis was applied to identify trait-related modules and then select key module-related DEGs. The optimized gene set of signatures was obtained using the least absolute shrinkage and selection operator (LASSO) regression analysis. The CIBERSORT algorithm and Pearson correlation test were used to analyze the relationship between gene signatures and immune cells. Finally, public databases were used to predict the transcription factors (TFs) and upstream miRNAs.

Results

A total of 127 DEGs in COPD were identified from the combined dataset. By considering the intersection of DEGs and genes in two trait-related modules, 83 key module-related DEGs were identified, which were mainly enriched in interleukin-related pathways. Seven-gene signatures, including MTHFD2, KANK3, GFPT2, PHLDA1, HS3ST2, FGG, and RPS4Y1, were further selected using the LASSO algorithm. These gene signatures showed the predictive potential for COPD risks and were significantly correlated with 18 types of immune cells. Finally, nine miRNAs and three TFs were predicted to target MTHFD2, GFPT2, PHLDA1, and FGG.

Conclusion

We proposed the seven-gene-signature to predict COPD risk and explored its potential immune characteristics and regulatory mechanisms.