Secreted proteins MDK, WFDC2, and CXCL14 as candidate biomarkers for early diagnosis of lung adenocarcinoma

Integrated analysis of single‑cell and bulk RNA sequencing data to construct a risk assessment model based on plasma cell immune‑related genes for predicting patient prognosis and therapeutic response in lung adenocarcinoma

Plasma cells serve a crucial role in the human immune system and are important in tumor progression. However, the specific role of plasma cell immune-related genes (PCIGs) in tumor progression remains unclear. Therefore, the present study aimed to establish a risk assessment model for patients with lung adenocarcinoma (LUAD) based on PCIGs. The data used in the present study were obtained from The Cancer Genome Atlas and the Gene Expression Omnibus databases. After identifying nine PCIGs, a risk assessment model was constructed and a nomogram was developed for predicting patient prognosis. To explore the molecular mechanism and clinical significance, gene set enrichment analysis (GSEA), tumor mutational burden (TMB) analysis, tumor microenvironment (TME) analysis and drug sensitivity prediction were performed. Furthermore, the accuracy of the model was validated using reverse transcription-quantitative PCR (RT-qPCR). The present study constructed a risk assessment model consisting of nine PCIGs. Kaplan-Meier survival curves indicated a worse prognosis in the high-risk subgroup (risk score ≥0.982) compared with that in the low-risk subgroup. The nomogram exhibited predictive value for survival prediction (area under the curve=0.727). GSEA enrichment analysis revealed enrichment of the focal adhesion and extracellular matrix-receptor interaction pathways in the high-risk group. Moreover, the high-risk group exhibited a higher TMB, as demonstrated by the TME analysis showing lower ESTIMATE scores. Drug sensitivity prediction facilitated potential drug selection. Subsequently, differential gene expression was validated in multiple LUAD cell lines using RT-qPCR. In conclusion, the risk assessment model based on nine PCIGs may be used to predict the prognosis and drug selection in patients with LUAD.

Malignant features related PRDX1 associated with osimertinib sensitivity of EGFR-mutant lung adenocarcinoma

The peroxiredoxin (PRDX) family, also known as the peroxidase family, consists of six members that participate in a variety of essential bio-processes in carcinogenesis. However, their molecular role in lung adenocarcinoma (LUAD) has not been systematically explored. Using bioinformatic tools, we systematically analyzed the expression, prognostic value and drug sensitivity of the PRDX gene family members in LUAD. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to verify the expression of PRDX1 in both LUAD tissues and cells. Cell Counting Kit-8 (CCK-8) assay was applied to detect the half-maximal inhibitory concentration (IC50) of osimertinib in LUAD. A series of cellular drug assays, including 5-Ethynyl-2'-deoxyuridine (EdU), colony formation, and apoptosis assays, were performed to explore the correlation of PRDX1 with epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) sensitivity by using EGFR-mutant and wild-type LUAD cell lines. Among all the PRDX family members, PRDX1 has a promising prognostic value and is associated with EGFR mutations, as verified by experiments conducted on collected LUAD specimens. In addition, pathway enrichment analysis suggested that PRDX1 expression positively correlated with DNA repair, which is often considered to be inextricably linked to drug resistance in tumor cells. Thus, we validated the correlation between PRDX1 and EGFR-TKI sensitivity through a series of in vitro experiments and found that PRDX1 inhibition along with osimertinib treatment resulted in synergistic inhibition of tumor growth. Moreover, we found that PRDX1 was negatively correlated with the immune infiltration of dendritic cells (DCs) in the tumor microenvironment (TME) of LUAD, further suggesting an oncogenic role of PRDX1. This study demonstrates that high PRDX1 expression could be a potential diagnostic and prognostic marker of LUAD, and the strategy of PRDX1 knockdown provides new insights into improving the therapeutic sensitivity of EGFR-TKI in patients with LUAD.

Pan-cancer secreted proteome and skeletal muscle regulation: insight from a proteogenomic data-driven knowledge base

Large-scale, pan-cancer analysis is enabled by data driven knowledge bases that link tumor molecular profiles with phenotypes. A debilitating cancer-related phenotype is skeletal muscle loss, or cachexia, which occurs partly from tumor products secreted into circulation. Using the LinkedOmicsKB knowledge base assembled from the Clinical Proteomics Tumor Analysis Consortium proteogenomic analysis, along with catalogs of human secretome proteins, ligand-receptor pairs and molecular signatures, we sought to identify candidate pan-cancer proteins secreted to blood that could regulate skeletal muscle phenotypes in multiple solid cancers. Tumor proteins having significant pan-cancer associations with muscle were referenced against secretome proteins secreted to blood from the Human Protein Atlas, then verified as increased in paired tumor vs. normal tissues in pan-cancer manner. This workflow revealed seven secreted proteins from cancers afflicting kidneys, head and neck, lungs and pancreas that classified as protein-binding activity modulator, extracellular matrix protein or intercellular signaling molecule. Concordance of these biomarkers with validated molecular signatures of cachexia and senescence supported relevance to muscle and cachexia disease biology, and high tumor expression of the biomarker set associated with lower overall survival. In this article, we discuss avenues by which skeletal muscle and cachexia may be regulated by these candidate pan-cancer proteins secreted to blood, and conceptualize a strategy that considers them collectively as a biomarker signature with potential for refinement by data analytics and radiogenomics for predictive testing of future risk in a non-invasive, blood-based panel amenable to broad uptake and early management.

CXCL14 in prostate cancer: complex interactions in the tumor microenvironment and future prospects

CXCL14 is a highly conserved chemokine expressed in various cell types, playing crucial roles in both physiological and pathological processes, including immune regulation and tumorigenesis. Recently, the role of CXCL14 in tumors has attracted considerable attention. However, previous pan-cancer studies have reported inconsistencies regarding the effects of CXCL14 on tumors, particularly concerning its expression levels in tumor tissues and its influence on various phenotypes of cancer cells. This variability is believed to stem from the context-dependent nature of CXCL14, as different sources of CXCL14 and its secretion within distinct tumor microenvironments may mediate diverse biological effects. Such phenomena have also been observed in prostate cancer research. Despite a foundational understanding of CXCL14 in prostate cancer, there remains a lack of comprehensive reviews summarizing the specific roles of this chemokine and systematically analyzing the reasons behind its complex effects. Therefore, this article aims to discuss the role of CXCL14 in the tumor microenvironment of prostate cancer and explore future research directions and potential applications.

The significance of MDK growth factor in the antler development of sika deer (Cervus nippon): An in-depth analysis

Deer antlers exhibit rapid growth during the velvet phase. As a critical endogenous growth factor in animals, midkine (MDK) is likely closely associated with the growth of antlers. However, the spatio-temporal expression pattern of MDK during the velvet phase was unclear. This study explored the physiological role of MDK by analyzing its molecular characterization and spatio-temporal expression dynamics during the growth of sika deer antlers. The study cloned the coding sequences (CDS) of MDK, which spanned 429 bp and encoded 142 amino acids. The results of bioinformatics prediction analysis showed that MDK was an extracellular hydrophilic secreted protein, which was mainly composed of random coil. MDK protein was relatively conserved in evolution and MDK protein of sika deer had the closest relatives to ruminants and the furthest relatives to Aves. The tip tissues (dermis, mesenchyme, precartilage, cartilage) of antlers were collected from three important growth and development nodes (early period, EP. middle period, MP. late period, LP), and quantitative real-time polymerase chain reaction (qRT-PCR) was chosen to detect the spatio-temporal expression of the MDK. The results showed that MDK was expressed in all tissue sites of antler tip in EP, MP, LP. MDK had a consistent expression pattern under all growth periods and was strongly expressed in dermis and cartilage. The expression of MDK was consistently up-regulated in precartilage, whereas it was first up-regulated and then down-regulated in other tissues, and it was highly significant in MP compared to EP and LP (P < 0.01). This study suggested that MDK may regulate the growth of dermis and cartilage tissues mainly by participating in the process of angiogenesis and bone formation, thus promoting the rapid growth of antlers.

Crosstalk between lncRNAs and Wnt/β-catenin signaling pathways in lung cancers: From cancer progression to therapeutic response

Lung cancer (LC) is considered to have the highest mortality rate around the world. Because there are no early diagnostic signs or efficient clinical alternatives, distal metastasis and increasing numbers of recurrences are a challenge in the clinical management of LC. Long non-coding RNAs (lncRNAs) have recently been recognized as a critical regulator involved in the progression and treatment response to LC. The Wnt/β-catenin pathway has been shown to influence LC occurrence and progress. Therefore, discovering connections between Wnt signaling pathway and lncRNAs may offer new therapeutic targets for improving LC treatment and management. In this review, the purpose of this article is to present possible therapeutic approaches by reviewing particular relationships, key processes, and molecules associated to the beginning and development of LC.

Identification of biomarkers for the early detection of non-small cell lung cancer: a systematic review and meta-analysis

Lung cancer (LC) causes few symptoms in the earliest stages, leading to one of the highest mortality rates among cancers. Low-dose computerised tomography (LDCT) is used to screen high-risk individuals, reducing the mortality rate by 20%. However, LDCT results in a high number of false positives and is associated with unnecessary follow-up and cost. Biomarkers with high sensitivities and specificities could assist in the early detection of LC, especially in patients with high-risk features. Carcinoembryonic antigen (CEA), cytokeratin 19 fragments and cancer antigen 125 have been found to be highly expressed during the later stages of LC but have low sensitivity in the earliest stages. We determined the best biomarkers for the early diagnosis of LC, using a systematic review of eight databases. We identified 98 articles that focussed on the identification and assessment of diagnostic biomarkers and achieved a pooled area under curve of 0.85 (95% CI 0.82-0.088), indicating that the diagnostic performance of these biomarkers when combined was excellent. Of the studies, 30 focussed on single/antigen panels, 22 on autoantibodies, 31 on miRNA and RNA panels, and 15 suggested the use of circulating DNA combined with CEA or neuron-specific enolase (NSE) for early LC detection. Verification of blood biomarkers with high sensitivities (Ciz1, exoGCC2, ITGA2B), high specificities (CYFR21-1, antiHE4, OPNV) or both (HSP90α, CEA) along with miR-15b and miR-27b/miR-21 from sputum may improve early LC detection. Further assessment is needed using appropriate sample sizes, control groups that include patients with non-malignant conditions, and standardised cut-off levels for each biomarker.

Midkine (MDK) in Hepatocellular Carcinoma: More than a Biomarker

Midkine (MDK) is a multifunctional secreted protein that can act as a cytokine or growth factor regulating multiple signaling pathways and being implicated in fundamental cellular processes, such as survival, proliferation, and migration. Although its expression in normal adult tissues is barely detectable, MDK serum levels are found to be elevated in several types of cancer, including hepatocellular carcinoma (HCC). In this review, we summarize the findings of recent studies on the role of MDK in HCC diagnosis and progression. Overall, studies show that MDK is a powerful biomarker for HCC early diagnosis, as it can differentiate not only between HCC patients and normal individuals but also between HCC patients and patients with other liver pathologies. It is correlated with high recurrence rates and was shown to be valuable for the diagnosis of early-stage HCC, even in patients negative for α-fetoprotein (AFP), the most commonly used biomarker for HCC diagnosis. A comparison with AFP reveals that MDK is inferior to AFP with regard to specificity but significantly superior with regard to sensitivity, which further indicates the need for using both biomarkers for more effective HCC diagnosis.

The role of midkine in health and disease

Midkine (MDK) is a neurotrophic growth factor highly expressed during embryogenesis with important functions related to growth, proliferation, survival, migration, angiogenesis, reproduction, and repair. Recent research has indicated that MDK functions as a key player in autoimmune disorders of the central nervous system (CNS), such as Multiple Sclerosis (MS) and is a promising therapeutic target for the treatment of brain tumors, acute injuries, and other CNS disorders. This review summarizes the modes of action and immunological functions of MDK both in the peripheral immune compartment and in the CNS, particularly in the context of traumatic brain injury, brain tumors, neuroinflammation, and neurodegeneration. Moreover, we discuss the role of MDK as a central mediator of neuro-immune crosstalk, focusing on the interactions between CNS-infiltrating and -resident cells such as astrocytes, microglia, and oligodendrocytes. Finally, we highlight the therapeutic potential of MDK and discuss potential therapeutic approaches for the treatment of neurological disorders.

Bone Marrow: The Central Immune System

Bone marrow is known as the site of hematopoiesis. What is not being described in textbooks of immunology is the fact that bone marrow is not only a generative, but also an antigen-responsive, immune organ. It is also a major storage site for antigen-specific memory B and T cells. That bone marrow is a priming site for T cell responses to blood borne antigens was discovered exactly 20 years ago. This review celebrates this important discovery. The review provides a number of examples of medical relevance of bone marrow as a central immune system, including cancer, microbial infections, autoimmune reactions, and bone marrow transplantation. Bone marrow mesenchymal stem cell-derived stromal cells provide distinct bone marrow niches for stem cells and immune cells. By transmitting anti-inflammatory dampening effects, facilitating wound healing and tissue regeneration mesenchymal stem cells contribute to homeostasis of bone and other tissues. Based on the evidence presented, the review proposes that bone marrow is a multifunctional and protective immune system. In an analogy to the central nervous system, it is suggested that bone marrow be designated as the central immune system.