CDGSH Iron Sulfur Domain 2 Activates Proliferation and EMT of Pancreatic Cancer Cells via Wnt/β-Catenin Pathway and Has Prognostic Value in Human Pancreatic Cancer

Molecular profile of metastasis, cell plasticity and EMT in pancreatic cancer: a pre-clinical connection to aggressiveness and drug resistance

The metastasis is a multistep process in which a small proportion of cancer cells are detached from the colony to enter into blood cells for obtaining a new place for metastasis and proliferation. The metastasis and cell plasticity are considered major causes of cancer-related deaths since they improve the malignancy of cancer cells and provide poor prognosis for patients. Furthermore, enhancement in the aggressiveness of cancer cells has been related to the development of drug resistance. Metastasis of pancreatic cancer (PC) cells has been considered one of the major causes of death in patients and their undesirable prognosis. PC is among the most malignant tumors of the gastrointestinal tract and in addition to lifestyle, smoking, and other factors, genomic changes play a key role in its progression. The stimulation of EMT in PC cells occurs as a result of changes in molecular interaction, and in addition to increasing metastasis, EMT participates in the development of chemoresistance. The epithelial, mesenchymal, and acinar cell plasticity can occur and determines the progression of PC. The major molecular pathways including STAT3, PTEN, PI3K/Akt, and Wnt participate in regulating the metastasis of PC cells. The communication in tumor microenvironment can provide by exosomes in determining PC metastasis. The components of tumor microenvironment including macrophages, neutrophils, and cancer-associated fibroblasts can modulate PC progression and the response of cancer cells to chemotherapy.

Multi-omics analysis reveals that ferroptosis-related gene CISD2 is a prognostic biomarker of head and neck squamous cell carcinoma

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is a prevalent malignancy, with high mortality rate and unavailability of accurate therapies. However, its early prevention remains a challenge. In the purview of predictive, preventive, and personalized medicine (PPPM), it is paramount to identify novel and powerful biomarkers. CISD2 is a crucial regulator of iron homeostasis and reactive oxygen species (ROS). Recent studies showed that the NEET protein (NAF-1) encoded by CISD2 is involved in regulating the proliferation and metastasis of tumor cells. Nevertheless, the prognostic value and immunological correlations of CISD2 remain unclear.

METHODS

Bioinformatics analyses conducted utilizing data from comprehensive databases The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). All statistical evaluations were executed employing R software.

RESULTS

Our investigation of biological function, enrichment pathway, and immune correlation revealed a discernable linkage between CISD2 and the immune response. Moreover, we found that the suppression of CISD2 is associated with immune cell infiltration and various immune signatures.

CONCLUSIONS

The present study successfully revealed the potential prognostic and biological function of CISD2 in HNSCC. High expression of CISD2 are linked to gender, race, grade, etc., can notably enhance the early detection, prognosis, and prediction for individuals afflicted with HNSCC.

CISD2 promotes lung squamous carcinoma cell migration and invasion via the TGF-β1-induced Smad2/3 signaling pathway

BACKGROUND

Although aberrant expression of CDGSH iron sulfur domain 2 (CISD2) contributes to the tumorigenesis and progression of numerous human cancers, the biological function of CISD2 and its specific prognostic value in lung squamous cell carcinoma (LUSC) have yet to be comprehensively explored. The current study aimed to elucidate the role of CISD2 in LUSC as well as the underlying molecular mechanisms.

METHODS

Immunohistochemistry was conducted to detect the protein expression of CISD2 and analyze whether high expression of CISD2 affects the overall survival (OS) of LUSC patients. Cell proliferation, colony formation, wound healing and Transwell invasion assays were performed to clarify whether CISD2 contributes to LUSC cell proliferation and disease progression. Quantitative real-time reverse transcription-PCR and western blot assays were used to detect the levels of transcription factors and key epithelial-mesenchymal transition (EMT)-related markers in LUSC cells after CISD2 knockdown and overexpression to determine whether CISD2 regulates transforming growth factor-beta (TGF-β)-induced EMT in LUSC.

RESULTS

Immunohistochemistry of human tissue microarrays containing 90 pairs of adjacent and cancerous tissues revealed that CISD2 is considerably overexpressed in LUSC and strongly linked to poor OS. Functional experiments suggested that silencing endogenous CISD2 inhibited the growth, colony formation, migration, and invasion of H2170 and H226 cell lines. Exogenous overexpression of CISD2 facilitated these phenotypes in SK-MES-1 and H2170 cells. Furthermore, CISD2 promoted EMT progression by increasing the expression of mesenchymal markers (N-cadherin, vimentin, Snail, and Slug) as well as SMAD2/3 and reducing the expression of the epithelial marker E-cadherin. Mechanistically, our studies provide the first evidence that CISD2 can promote EMT by enhancing TGF-β1-induced Smad2/3 expression in LUSC cells.

CONCLUSION

In conclusion, our research illustrates that CISD2 is highly expressed in LUSC and may facilitate LUSC proliferation and metastasis. Thus, CISD2 may serve as an independent prognostic marker and possible treatment target for LUSC.

CISD2 Promotes Proliferation of Colorectal Cancer Cells by Inhibiting Autophagy in a Wnt/β-Catenin-Signaling-Dependent Pathway

The aim of this study is to investigate the role of CDGSH iron-sulfur domain 2 (CISD2) in colorectal cancer (CRC). The purpose of this study was to investigate the role of CDGSH iron-sulfur domain 2 (CISD2) in colorectal cancer (CRC) progression. The expression of CISD2 in CRC cell lines was measured by western blotting. Functional assays including MTT assays and colony formation assays were performed to explore the role of CISD2 in regulating tumor growth. Flow cytometry analysis was used to examine the percentage of apoptotic CRC cells. Expression of apoptosis-related gene, autophagy-related markers, and the protein included in Wnt/β-Catenin signaling was also determined by western blotting. The in vivo role of CISD2 was also examined in a xenograft model. CISD2 expression was significantly increased in CRC cells. CISD2 promoted the CRC cell proliferation and inhibited the apoptosis and autophagy of CRC cells. Moreover, knockdown of CISD2 inhibited the activation of Wnt/β-Catenin-signaling pathway. Knockdown of CISD2 inhibited the tumor growth in nude mice. CISD2 promoted colorectal cancer development by inhibiting CRC cell apoptosis and autophagy depending on activating Wnt/β-Catenin-signaling pathway.

A peptide-derived strategy for specifically targeting the mitochondria and ER of cancer cells: a new approach in fighting cancer

An effective anti-cancer therapy should exclusively target cancer cells and trigger in them a broad spectrum of cell death pathways that will prevent avoidance. Here, we present a new approach in cancer therapy that specifically targets the mitochondria and ER of cancer cells. We developed a peptide derived from the flexible and transmembrane domains of the human protein NAF-1/CISD2. This peptide (NAF-144-67) specifically permeates through the plasma membranes of human epithelial breast cancer cells, abolishes their mitochondria and ER, and triggers cell death with characteristics of apoptosis, ferroptosis and necroptosis. In vivo analysis revealed that the peptide significantly decreases tumor growth in mice carrying xenograft human tumors. Computational simulations of cancer vs. normal cell membranes reveal that the specificity of the peptide to cancer cells is due to its selective recognition of their membrane composition. NAF-144-67 represents a promising anti-cancer lead compound that acts via a unique mechanism.

High Expression of CISD2 in Relation to Adverse Outcome and Abnormal Immune Cell Infiltration in Glioma

Glioma is a serious disease burden globally, with high mortality and recurrence rates. CDGSH iron sulfur domain 2 (CISD2) is an evolutionarily conserved protein that is involved in several cancers. However, its role in the prognosis and immune infiltration in glioma remains unclear. In our research, RNA-seq matrix and clinicopathological relevant data for CISD2 were downloaded from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) databases. Human Protein Atlas was used to verify the CISD2 protein level in glioma, and STRING was used to establish relative coexpression gene network. The Kaplan-Meier plotter was adopted to analyze the effect of CISD2 on prognosis. The connection between CISD2 expression and immune infiltration was analyzed using single-sample GSEA (ssGSEA), TIMER, and GEPIA. In contrast to normal tissues, CISD2 expression was significantly higher in glioma tissues, and CISD2 presented a certain diagnostic value in distinguishing glioma tissues from normal tissues. Furthermore, the CISD2 level was correlated with age, histologic grade, histological type, isocitrate dehydrogenase (IDH) status, 1p/19q codeletion status, and primary therapy outcome of glioma, while high CISD2 mRNA expression was correlated with grave overall survival. Multivariate analysis demonstrated that CISD2 was an independent risk factor for patients with glioma. Functional enrichment analysis indicated that CISD2 could regulate proliferation, immune reaction, and mitochondrial function. The results from the ssGSEA and TIMER databases confirmed that CISD2 acts a prominent role in immune cell infiltration in the tumor microenvironment, especially in low-grade glioma (LGG). Furthermore, CISD2 expression was observably correlated to M2 polarization in macrophages with glioma progression. This is the first research to investigate the immune role of CISD2 in glioma. CISD2 may be an innovative prognostic biomarker and can act as a potential target for future therapy for glioma.

Long non-coding RNA NRAV enhances proliferation and invasion of hepatocellular carcinoma cells by modulating the Wnt/β-catenin signaling pathway

Many dysregulated lncRNAs have been reported to perform an integral function in hepatocellular carcinoma (HCC). However, the role of long non-coding RNA (lncRNA) NRAV in HCC has not been elucidated. To address this issue, we investigated the function of NRAV in HCC in this research. Through bioinformatics prediction and real-time quantitative polymerase chain reaction validation, we found that NRAV plays an upmodulating role in HCC cells and tissues, and patients with high NRAV expression showed a poor prognosis. Cell viability was examined by conducting a Cell Counting Kit-8 analysis. Subsequently, the proliferation capacity of the cells was analyzed utilizing cell colony formation assay, and transwell invasion experiments were conducted to identify the cell invasion ability. To determine the association between NRAV and miR-199a-3p, and CDGSH iron-sulfur domain-containing protein 2 (CISD2), we conducted a dual luciferase assay. The protein and gene expressions were estimated utilizing Western blot. Findings illustrated that the overexpression of NRAV enhanced the HCC cell viability, proliferation and invasion, whereas they were inhibited significantly by down expression of NRAV. The dual-luciferase assay showed that miR-199a-3p is not only a target for NRAV but also interacts with the 3' UTR of CISD2 in HCC cells. MiR-199a-3p/CISD2 axis performs a function in NRAV-mediated cell behavior regulation. NRAV may trigger the Wnt/β-catenin signaling via the modulation of the miR-199a-3p/CISD2 axis in HCC. The findings of this work can provide novel insights into clinical diagnosis and the treatment of HCC in the future.Abbreviations: HCC, hepatocellular carcinoma; LncRNA, long non-coding RNA; CISD2, CDGSH iron-sulfur domain-containing protein 2; CCK-8, Cell Counting Kit-8; cDNA, single-stranded complementary DNA; RT-qPCR, real-time quantitative polymerase chain reaction; BCA, bicinchoninic acid; ceRNA, competing endogenous RNAs.

Disrupting CISD2 function in cancer cells primarily impacts mitochondrial labile iron levels and triggers TXNIP expression

The CISD2 (NAF-1) protein plays a key role in regulating cellular homeostasis, aging, cancer and neurodegenerative diseases. It was found to control different calcium, reactive oxygen species (ROS), and iron signaling mechanisms. However, since most studies of CISD2 to date were conducted with cells that constitutively lack, overexpress, or contain mutations in CISD2, the relationships between these different signaling processes are unclear. To address the hierarchy of signaling events occurring in cells upon CISD2 disruption, we developed an inducible system to express CISD2, or the dominant-negative H114C inhibitor of CISD2, in human breast cancer cells. Here, we report that inducible disruption of CISD2 function causes an immediate disruption in mitochondrial labile iron (mLI), and that this disruption results in enhanced mitochondrial ROS (mROS) levels. We further show that alterations in cytosolic and ER calcium levels occur only after the changes in mLI and mROS levels happen and are unrelated to them. Interestingly, disrupting CISD2 function resulted in the enhanced expression of the tumor suppressor thioredoxin-interacting protein (TXNIP) that was dependent on the accumulation of mLI and associated with ferroptosis activation. CISD2 could therefore regulate the expression of TXNIP in cancer cells, and this regulation is dependent on alterations in mLI levels.

CISD2 Promotes Resistance to Sorafenib-Induced Ferroptosis by Regulating Autophagy in Hepatocellular Carcinoma

Purpose

Sorafenib is a multi-kinase inhibitor that is used as a standard treatment for advanced hepatocellular carcinoma (HCC). However, the mechanism of sorafenib resistance in HCC is still unclear. It has been shown that CISD2 expression is related to the progression and poor prognosis of HCC. Here, we show a new role for CISD2 in sorafenib resistance in HCC.

Methods

Bioinformatic analysis was used to detect the expression of negative regulatory genes of ferroptosis in sorafenib-resistant samples. The concentration gradient method was used to establish sorafenib-resistant HCC cells. Western blot was used to detect the protein expression of CISD2, LC3, ERK, PI3K, AKT, mTOR, and Beclin1 in HCC samples. Quantitative real-time PCR (qPCR) was used to detect gene expression. CISD2 shRNA and Beclin1 shRNA were transfected to knock down the expression of the corresponding genes. Cell viability was detected by a CCK-8 assay. ROS were detected by DCFH-DA staining, and MDA and GSH were detected with a Lipid Peroxidation MDA Assay Kit and Micro Reduced Glutathione (GSH) Assay Kit, respectively. Flow cytometry was used to detect apoptosis and the levels of ROS and iron ions.

Results

CISD2 was highly expressed in HCC cells compared with normal cells and was associated with poor prognosis in patients. Knockdown of CISD2 promoted a decrease in the viability of drug-resistant HCC cells. CISD2 knockdown promoted sorafenib-induced ferroptosis in resistant HCC cells. The levels of ROS, MDA, and iron ions increased, but the change in GSH was not obvious. Knockdown of CISD2 promoted uncontrolled autophagy in resistant HCC cells. Inhibition of autophagy attenuated CISD2 knockdown-induced ferroptosis. The autophagy promoted by CISD2 knockdown was related to Beclin1. When CISD2 and Beclin1 were inhibited, the effect on ferroptosis was correspondingly weakened.

Conclusion

Inhibition of CISD2 promoted sorafenib-induced ferroptosis in resistant cells, and this process promoted excessive iron ion accumulation through autophagy, leading to ferroptosis. The combination of CISD2 inhibition and sorafenib treatment is an effective therapeutic strategy for resistant HCC.

New Insights of the NEET Protein CISD2 Reveals Distinct Features Compared to Its Close Mitochondrial Homolog mitoNEET

Human CISD2 and mitoNEET are two NEET proteins anchored in the endoplasmic reticulum and mitochondria membranes respectively, with an Fe–S containing domain stretching out in the cytosol. Their cytosolic domains are close in sequence and structure. In the present study, combining cellular and biochemical approaches, we compared both proteins in order to possibly identify specific roles and mechanisms of action in the cell. We show that both proteins exhibit a high intrinsic stability and a sensitivity of their cluster to oxygen. In contrast, they differ in according to expression profiles in tissues and intracellular half-life. The stability of their Fe–S cluster and its ability to be transferred in vitro are affected differently by pH variations in a physiological and pathological range for cytosolic pH. Finally, we question a possible role for CISD2 in cellular Fe–S cluster trafficking. In conclusion, our work highlights unexpected major differences in the cellular and biochemical features between these two structurally close NEET proteins.

CISD2 plays a role in age-related diseases and cancer

CDGSH iron-sulfur domain 2 (Cisd2) is an evolutionarily conserved protein that plays an important regulatory role in aging-related diseases and cancers. Since its discovery, Cisd2 has been identified as a regulatory factor for the aging of the human body and the regulation of mammalian lifespan. Cisd2 is also an oncoprotein that regulates the occurrence and development of cancer. Cisd2 mediates the occurrence of diseases related to human aging and the proliferation, differentiation, metastasis, and invasion of various cancer cells through various mechanisms. Multiple studies have shown that Cisd2 expression is related to the clinical characteristics of aging-related diseases and patients with cancer, and its expression profile is a novel diagnostic and prognostic biomarker for a variety of human diseases. Modulating the expression or function of Cisd2 may be a potential treatment strategy for different diseases. In this review, we summarize the role of Cisd2 in human aging-related diseases and various cancers, as well as the biological functions, underlying mechanisms, and potential clinical significance.

CISD2 maintains cellular homeostasis

CDGSH Iron Sulfur Domain 2 (CISD2) is the causative gene for the disease Wolfram syndrome 2 (WFS2; MIM 604928), which is an autosomal recessive disorder showing metabolic and neurodegenerative manifestations. CISD2 protein can be localized on the endoplasmic reticulum (ER), outer mitochondrial membrane (OMM) and mitochondria-associated membrane (MAM). CISD2 plays a crucial role in the regulation of cytosolic Ca²⁺ homeostasis, ER integrity and mitochondrial function. Here we summarize the most updated publications and discuss the central role of CISD2 in maintaining cellular homeostasis. This review mainly focuses on the following topics. Firstly, that CISD2 has been recognized as a prolongevity gene and the level of CISD2 is a key determinant of lifespan and healthspan. In mice, Cisd2 deficiency shortens lifespan and accelerates aging. Conversely, a persistently high level of Cisd2 promotes longevity. Intriguingly, exercise stimulates Cisd2 gene expression and thus, the beneficial effects offered by exercise may be partly related to Cisd2 activation. Secondly, that Cisd2 is down-regulated in a variety of tissues and organs during natural aging. Three potential mechanisms that may mediate the age-dependent decrease of Cisd2, via regulating at different levels of gene expression, are discussed. Thirdly, the relationship between CISD2 and cell survival, as well as the potential mechanisms underlying the cell death control, are discussed. Finally we discuss that, in cancers, CISD2 may functions as a double-edged sword, either suppressing or promoting cancer development. This review highlights the importance of the CISD2 in aging and age-related diseases and identifies the urgent need for the translation of available genetic evidence into pharmaceutic interventions in order to alleviate age-related disorders and extend a healthy lifespan in humans.

The balancing act of NEET proteins: Iron, ROS, calcium and metabolism

NEET proteins belong to a highly conserved group of [2Fe-2S] proteins found across all kingdoms of life. Due to their unique [2Fe2S] cluster structure, they play a key role in the regulation of many different redox and oxidation processes. In eukaryotes, NEET proteins are localized to the mitochondria, endoplasmic reticulum (ER) and the mitochondrial-associated membranes connecting these organelles (MAM), and are involved in the control of multiple processes, ranging from autophagy and apoptosis to ferroptosis, oxidative stress, cell proliferation, redox control and iron and iron‑sulfur homeostasis. Through their different functions and interactions with key proteins such as VDAC and Bcl-2, NEET proteins coordinate different mitochondrial, MAM, ER and cytosolic processes and functions and regulate major signaling molecules such as calcium and reactive oxygen species. Owing to their central role in cells, NEET proteins are associated with numerous human maladies including cancer, metabolic diseases, diabetes, obesity, and neurodegenerative diseases. In recent years, a new and exciting role for NEET proteins was uncovered, i.e., the regulation of mitochondrial dynamics and morphology. This new role places NEET proteins at the forefront of studies into cancer and different metabolic diseases, both associated with the regulation of mitochondrial dynamics. Here we review recent studies focused on the evolution, biological role, and structure of NEET proteins, as well as discuss different studies conducted on NEET proteins function using transgenic organisms. We further discuss the different strategies used in the development of drugs that target NEET proteins, and link these with the different roles of NEET proteins in cells.

MCM2 and NUSAP1 Are Potential Biomarkers for the Diagnosis and Prognosis of Pancreatic Cancer

Pancreatic cancer (PC) is one of the most malignant tumors. Despite considerable progress in the treatment of PC, the prognosis of patients with PC is poor. The aim of this study was to identify potential biomarkers for the diagnosis and prognosis of PC. First, the original data of three independent mRNA expression datasets were downloaded from the Gene Expression Omnibus and The Cancer Genome Atlas databases and screened for differentially expressed genes (DEGs) using the R software. Subsequently, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses of the DEGs were performed, and a protein-protein interaction (PPI) network was constructed to screen for hub genes. The hub genes were analyzed for genetic variations, as well as for survival, prognostic, and diagnostic value, using the cBioPortal and Gene Expression Profiling Interactive Analysis (GEPIA) databases and the pROC package. After screening for potential biomarkers, the mRNA and protein levels of the biomarkers were verified at the tissue and cellular levels using the Cancer Cell Line Encyclopedia, GEPIA, and the Human Protein Atlas. As a result, a total of 248 DEGs were identified. The GO terms enriched in DEGs were related to the separation of mitotic sister chromatids and the binding of the spindle to the extracellular matrix. The enriched pathways were associated with focal adhesion, ECM-receptor interaction, and phosphatidylinositol 3-kinase (PI3K)/AKT signaling. The top 20 genes were selected from the PPI network as hub genes, and based on the analysis of multiple databases, MCM2 and NUSAP1 were identified as potential biomarkers for the diagnosis and prognosis of PC. In conclusion, our results show that MCM2 and NUSAP1 can be used as potential biomarkers for the diagnosis and prognosis of PC. The study also provides new insights into the underlying molecular mechanisms of PC.

Linc00261 inhibits metastasis and the WNT signaling pathway of pancreatic cancer by regulating a miR‑552‑5p/FOXO3 axis

The biological function of long non-coding RNA00261 (Linc00261) has been widely investigated in various types of cancer. The aim of the present study was to explore the role of Linc00261 in pancreatic cancer (PC). The expression of Linc00261 in patients with PC and PC cell lines was assessed using reverse transcription-quantitative PCR and the association of Linc00261 expression with survival was analyzed in the online database, GEPIA. The effects of Linc00261 on PC cell metastasis in vitro and in vivo were determined using a wound healing assay, Transwell invasion assays and a nude mouse model of liver metastasis. The relationship between Linc00261, the miR-552-5p/forkhead box O3 (FOXO3) axis and the Wnt signaling pathway were determined using bioinformatics analysis, dual luciferase assay and western blotting. Linc00261 expression was significantly decreased in PC tissues and cell lines, and reduced expression was associated with less favorable outcomes in patients with PC. Linc00261 overexpression inhibited migration and invasion of PC cells in vitro, whereas knockdown of Linc00261 increased migration and invasion. Linc00261 overexpression also decreased metastasis of PC cells in vivo. Linc00261 was revealed to directly bind to microRNA (miR)-552-5p and to decrease the expression of miR-552-5p. In addition, Linc00261 overexpression increased the expression of FOXO3, a target gene of miR-552-5p, as well as inhibited the Wnt signaling pathway. Overexpression of miR-552-5p in Linc00261-overexpressing PC cells increased migration and invasion, as well as decreased the expression of FOXO3 and members of the Wnt signaling pathway. Collectively, the present study demonstrated that Linc00261 inhibited metastasis and the Wnt signaling pathway of PC by regulating the miR-552-5p/FOXO3 axis. Linc00261 may suppress the development of PC, and serve as a potential biomarker and effective target for the diagnosis and treatment of PC.

INPP4B As A Prognostic And Diagnostic Marker Regulates Cell Growth Of Pancreatic Cancer Via Activating AKT

Background

Inositol polyphosphate 4-phosphatase type II (INPP4B), a member of the PI3K/Akt signaling pathway, plays a vital role in the initiation and progression of cancers. However, its biological role in pancreatic cancer remains largely undiscovered. Our study aimed to investigate the effects of INPP4B on proliferation in pancreatic cancer and its clinical relevance.

Materials and methods

INPP4B expression data were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Clinicopathological and survival data were retrieved from the TCGA database. CCK8 and colony formation assays were performed to measure the proliferative capacity of pancreatic cancer. Tumor xenograft models were established to measure cancer proliferative abilities in vivo.

Results

INPP4B was upregulated in pancreatic cancer tissue compared with normal tissue. INPP4B knockdown inhibited cell proliferation and promoted apoptosis in pancreatic cancer in vitro and in vivo. INPP4B knockdown also reduced AKT phosphorylation. Moreover, INPP4B was associated with poor overall and disease-free survival, with Cox regression analysis showing that INPP4B could serve as an independent prognostic marker. ROC curve analysis showed that INPP4B possessed moderate diagnostic value.

Conclusion

Collectively, INPP4B is an oncogenic gene in pancreatic cancer and could serve as a potential diagnostic marker and an independent prognostic marker, suggesting that it could be a novel therapeutic target for pancreatic cancer.

PRPF40A as a potential diagnostic and prognostic marker is upregulated in pancreatic cancer tissues and cell lines: an integrated bioinformatics data analysis

Background

Pre-mRNA processing factor 40 homolog A (PRPF40A) is an important protein involved in pre-mRNA splicing and is expressed in a variety of cell types. However, the function of PRPF40A in pancreatic cancer remains unclear. Therefore, our study is to investigate the role of PRPF40A in the pathogenesis of pancreatic cancer.

Materials and methods

We extracted expression data and clinical information of PRPF40A from different online databases, including the Cancer Genome Atlas (TCGA), Oncomine and the Gene Expression Omnibus (GEO). Subsequently, samples were collected from patients to validate gene expression using qPCR, Western blotting and immunohistochemical (IHC) analyses. Receiver operating characteristic (ROC) and Kaplan-Meier curve were used to evaluate the diagnostic and prognostic potential. Colony formation assays and CCK-8 assays were performed to measure the proliferative capacity of pancreatic cancer. Finally, gene ontology (GO) and pathway enrichment analyses of co-expressed genes of PRPF40A were conducted using the Database for Annotation, Visualization and Integrated Discovery (DAVID).

Results

We found that PRPF40A was upregulated based on data from both the online databases and our samples. PRPF40A possessed a significant diagnostic value, and its overexpression was associated with poor prognosis. PRPF40A knockdown inhibited cell proliferation in pancreatic cancer. GO and pathway analysis showed that the co-expressed genes were mainly involved in viral processing, mRNA splicing and the AMPK signaling pathway.

Conclusion

The results suggest that PRPF40A is an oncogene and can serve as a diagnostic and prognostic biomarker for pancreatic cancer. However, the underlying mechanisms remain to be elucidated.

NEET Proteins: A New Link Between Iron Metabolism, Reactive Oxygen Species, and Cancer

SIGNIFICANCE

Cancer cells accumulate high levels of iron and reactive oxygen species (ROS) to promote their high metabolic activity and proliferation rate. However, high levels of iron and ROS can also lead to enhanced oxidative stress and the activation of cell death pathways such as apoptosis and ferroptosis. This has led to the proposal that different drugs that target iron and/or ROS metabolism could be used as anticancer drugs. However, due to the complex role iron and ROS play in cells, the majority of these drugs yielded mixed results, highlighting a critical need to identify new players in the regulation of iron and ROS homeostasis in cancer cells. Recent Advances: NEET proteins belong to a newly discovered class of iron-sulfur proteins (2Fe-2S) required for the regulation of iron and ROS homeostasis in cells. Recent studies revealed that the NEET proteins NAF-1 (CISD2) and mitoNEET (CISD1) play a critical role in promoting the proliferation of cancer cells, supporting tumor growth and metastasis. Moreover, the function of NEET proteins in cancer cells was found to be dependent of the degree of lability of their 2Fe-2S clusters.

CRITICAL ISSUES

NEET proteins could represent a key regulatory link between the maintenance of high iron and ROS in cancer cells, the activation of cell death and survival pathways, and cellular proliferation.

FUTURE DIRECTIONS

Because the function of NEET proteins depends on the lability of their clusters, drugs that target the 2Fe2S clusters of NEET proteins could be used as promising anticancer drugs.

Mn12Ac inhibits the migration, invasion and epithelial-mesenchymal transition of lung cancer cells by downregulating the Wnt/β-catenin and PI3K/AKT signaling pathways

Lung cancer is the leading cause of global cancer-associated mortality, therefore it is important to reveal the molecular mechanisms of lung cancer progression and to develop novel therapeutic targets. The results of the present study identified that manganese-12 acetate (Mn12Ac) was able to significantly inhibit the migration and invasion of A549 cells. Western blotting demonstrated that treatment with Mn12Ac was able to upregulate E-cadherin, and downregulate N-cadherin and vimentin. It was also identified by a quantitative polymerase chain reaction analysis that Mn12Ac was able to reduce the mRNA expression levels of EMT-associated transcription factors Snail, Slug, Twist-related protein 1 and zinc finger E-box-binding homeobox 1. It was also demonstrated that Mn12Ac was able to reduce the expression levels of Wnt and β-catenin proteins, and suppress the phosphorylation of phosphoinositide 3-kinase (PI3K) and AKT in A549 cells. Notably, it was revealed that Mn12Ac was able to decrease the mRNA and protein expression levels of programmed death ligand-1. Taken together, the results suggested that Mn12Ac is able to inhibit cell migration, invasion and EMT in lung cancer cells by regulating the Wnt/β-catenin and PI3K/AKT signaling pathways.

Phylogenetic analysis of the CDGSH iron-sulfur binding domain reveals its ancient origin

The iron-sulfur (2Fe-2S) binding motif CDGSH appears in many important plant and animal proteins that regulate iron and reactive oxygen metabolism. In human it is found in CISD1-3 proteins involved in diabetes, obesity, cancer, aging, cardiovascular disease and neurodegeneration. Despite the important biological role of the CDGSH domain, its origin, evolution and diversification, are largely unknown. Here, we report that: (1) the CDGSH domain appeared early in evolution, perhaps linked to the heavy use of iron-sulfur driven metabolism by early organisms; (2) a CISD3-like protein with two CDGSH domains on the same polypeptide appears to represent the ancient archetype of CDGSH proteins; (3) the origin of the human CISD3 protein is linked to the mitochondrial endosymbiotic event; (4) the CISD1/2 type proteins that contain only one CDGSH domain, but function as homodimers, originated after the divergence of bacteria and archaea/eukaryotes from their common ancestor; and (5) the human CISD1 and CISD2 proteins diverged about 650–720 million years ago, and CISD3 and CISD1/2 share their descent from an ancestral CISD about 1–1.1 billion years ago. Our findings reveal that the CDGSH domain is ancient in its origin and shed light on the complex evolutionary path of modern CDGSH proteins.