Migration Of Lung Adenocarcinoma Cells Research Articles

HOXD1 inhibits lung adenocarcinoma progression and is regulated by DNA methylation.

The homeobox (HOX) gene family encodes a number of highly conserved transcription factors and serves a crucial role in embryonic development and tumorigenesis. Homeobox D1 (HOXD1) is a member of the HOX family, whose biological functions in lung cancer are currently unclear. The University of Alabama at Birmingham Cancer data analysis Portal of HOXD1 expression patterns demonstrated that HOXD1 was downregulated in lung adenocarcinoma (LUAD) patient samples compared with adjacent normal tissue. Western blotting analysis demonstrated low HOXD1 protein expression levels in lung LUAD cell lines. The Kaplan‑Meier plotter database demonstrated that reduced HOXD1 expression levels in LUAD correlated with poorer overall survival. Meanwhile, an in vitro study showed that HOXD1 overexpression suppressed LUAD cell proliferation, migration and invasion. In a mouse tumor model, upregulated HOXD1 was demonstrated to inhibit tumor growth. In addition, targeted bisulfite sequencing and chromatin immunoprecipitation assays demonstrated that DNA hypermethylation occurred in the promoter region of the HOXD1 gene and was associated with the action of DNA methyltransferases. Moreover, upregulated HOXD1 served as a transcriptional factor and increased the transcriptional expression of bone morphogenic protein (BMP)2 and BMP6. Taken together, the dysregulation of HOXD1 mediated by DNA methylation inhibited the initiation and progression of LUAD by regulating the expression of BMP2/BMP6.

Nicotine promotes M2 macrophage polarization through α5-nAChR/SOX2/CSF-1 axis in lung adenocarcinoma

α5-nicotinic acetylcholine receptor (α5-nAChR) plays a vital part in lung adenocarcinoma (LUAD). However, it is not comprehensively understood that how the α5-nAChR affects LUAD. Through diverse bioinformatics analyses and immunohistochemistry, the expressions of α5-nAChR and SOX2 as well as their relations were dissected. α5-nAChR regulated the differentiation of monocytes into M2 macrophages by targeting the STAT3/SOX2/CSF-1 signaling in the coculture system by western blotting and ChIP. α5-nAChR-mediated macrophage-mediated LUAD cell migration via SOX2/CSF-1 signaling in the cocultured medium. Correlations of α5-nAChR, SOX2 and M2 phenotype tumor-associated macrophages (TAMs) were validated in mouse LUAD models and clinical samples. α5-nAChR expression was connected to SOX2 expression, smoking and bad prognosis of LUAD among clinical samples. Nicotine-induced SOX2 expression was mediated by α5-nAChR via STAT3. Additionally, SOX2-mediated macrophage colony-stimulating factor (CSF-1) expression contributed to LUAD progression in vitro. Furthermore, α5-nAChR expression was strongly linked to pSTAT3, SOX2 and M2 macrophage marker CD206 expression and negatively correlated with M1 macrophage marker CD86 expression in vivo. It is indicated that M2 macrophages are mediated by the new α5-nAChR /SOX2/CSF-1 axis in nicotine-related LUAD, which is a potential therapeutic strategy for cancer.

Inhibition of JNK/STAT3/NF-KB pathway-mediated migration and clonal formation of lung adenocarcinoma A549 cells by daphnetin

ABSTRACT Daphnetin, a coumarin derivative isolated from Daphne odorifera, has anti-tumor effects. The MAPK, STAT3, and NF-κB signaling pathways are closely related to the pathogenesis of lung cancer. To investigate the effect of daphnetin on anti-lung adenocarcinoma A549 cells and its mechanism. The anti-tumor effects of daphnetin on the proliferation, clone formation, migration, and invasion of A549 lung adenocarcinoma cells were investigated. The results showed that daphnetin inhibited the proliferation, colony formation, migration, and invasion of A549 cells through the MAPK/STAT3/NF-KB pathway, and mainly inhibited the clonal formation and migration of A549 cells through the JNK pathway. These results provide a new research direction and theoretical basis for the use of daphnetin in the inhibition of lung adenocarcinoma.

Hsa_circ_0001492 regulates the hsa-miR-145-5p/ovarian carcinoma immunoreactive antigen domain 2 axis to promote the progression of lung adenocarcinoma.

Circular RNA (circRNA) has been proven to be a key regulator in a range of tumor illnesses, such as lung adenocarcinoma (LUAD); however, the regulatory mechanisms of circRNA remain unclear. In this study, circRNA (hsa_circ_0001492) in LUAD was examined for its regulatory and functional potential. qRT-PCR was used to assess the hsa_circ_0001492 level in LUAD. The RNAse R digestion test was employed to isolate hsa_circ_0001492. The primary location of hsa_circ_0001492 enrichment in LUAD cells was identified through a nucleoplasmic separation test. LUAD cell migration, proliferation, and spherogenicity were examined using wound healing, transwell, EdU, and cell spherogenicity assays. The association between miR-145-5p and hsa_circ_0001492/ovarian carcinoma immunoreactive antigen domain 2 (OCIAD2) was validated using a dual luciferase experiment. The interaction between sh-hsa_circ_0001492 and miR-145-5p was confirmed through an RNA pull-down assay. The effects of hsa_circ_0001492, miR-145-5p, and OCIAD2 on LUAD tumor development were examined using xenograft mouse models and immunohistochemistry tests. Results showed a higher amount of hsa_circ_0001492 in LUAD. The cytoplasm of LUAD cells was observed in the area where hsa_circ_0001492 mainly accumulated; hsa_circ_0001492 enhanced LUAD cell migration, proliferation, and sphere-forming ability. MiR-145-5p and OCIAD2 were identified as targets of hsa_circ_0001492 and miR-145-5p, respectively. The level of OCIAD2 was increased by hsa_circ_0001492 through targeted binding to miR-145-5p. In nude mice, tumor growth was inhibited by silencing hsa_circ_0001492, while knockdown of miR-145-5p and overexpression of OCIAD2 promoted the growth of LUAD tumors. In conclusion, hsa_circ_0001492 regulates the hsa-miR-145-5p/OCIAD2 axis to promote the progression of LUAD, and could be a useful target for the diagnosis and treatment of LUAD.

Identification of a Novel Signature Based on Ferritinophagy-Related Genes to Predict Prognosis in Lung Adenocarcinoma: Focus on AHNAK2

Background: Lung adenocarcinoma (LUAD) accounts for over 40% of all non-small cell lung cancer (NSCLC) cases and continues to be difficult to treat despite advancements in diagnostics and therapies. Ferritinophagy, a newly recognized autophagy process linked to ferroptosis, has been associated with LUAD development. Recent studies have shown a dysregulation of genes related to ferritinophagy in LUAD, indicating its potential as a therapeutic target. Methods: We constructed a predictive model using seven genes associated with ferritinophagy. The model’s accuracy was evaluated across three independent gene expression datasets. We analyzed the biological functions, immune environment, mutations, and drug sensitivities in groups with high and low risk. Utilizing a single-cell sequencing (scRNA-seq) dataset, we confirmed the expression of the model genes and identified a subtype of epithelial cells expressing AHNAK2. We further investigated the impact of the ferritinophagy-related gene AHNAK2 on LUAD cell proliferation, invasion, migration, and ferroptosis in vitro. Results: Our prediction model, comprising seven genes (AHNAK2, ARNTL2, CD27, LTB, SLC15A1, SLC2A1, and SYT1), has shown potential in predicting the prognosis of individuals diagnosed with LUAD. Notably, AHNAK2 impedes ferroptosis, promoting LUAD progression in vitro. Conclusions: Our research suggests that ferritinophagy-associated genes are promising prognostic markers for LUAD and lay the groundwork for further exploration of ferritinophagy’s role in LUAD. Furthermore, we present AHNAK2 as a novel regulator of ferroptosis, which requires further investigation to understand its mechanism.

S100A16 stabilizes the ITGA3‑mediated ECM‑receptor interaction pathway to drive the malignant properties of lung adenocarcinoma cells via binding MOV10.

Lung adenocarcinoma (LUAD) is highly associated with lung cancer‑associated mortality. Notably, S100 calcium‑binding protein A16 (S100A16) has been increasingly considered to have prognostic value in LUAD; however, the underlying mechanism remains unknown. In the present study, S100A16 expression levels in LUAD tissues and cells were respectively analyzed by the UALCAN database and western blotting. Cell Counting Kit‑8 and 5‑ethynyl‑2'‑deoxyuridine assays were used to examine cell proliferation, whereas wound healing, Transwell and tube formation assays were used to assess cell migration, invasion and angiogenesis, respectively. Western blotting was also used to examine the expression levels of proteins associated with metastasis, angiogenesis, focal adhesion and the extracellular matrix (ECM)‑receptor interaction pathways. The relationship between S100A16 and Mov10 RNA helicase (MOV10) was predicted by bioinformatics tools, and was verified using a co‑immunoprecipitation assay. Furthermore, the interaction between MOV10 and integrin α3 (ITGA3) was verified by RNA immunoprecipitation assay, and the actinomycin D assay was used to detect ITGA3 mRNA stability. The results demonstrated that S100A16 expression was increased in LUAD tissues and cell lines, and was associated with unfavorable outcomes. Knocking down S100A16 expression hindered the proliferation, migration, invasion and angiogenesis of LUAD cells. Furthermore, S100A16 was shown to bind to MOV10 and positively modulate MOV10 expression in LUAD cells, while MOV10 overexpression partially reversed the suppressive role of S100A16 knockdown on the aggressive phenotypes of LUAD cells. Furthermore, it was demonstrated that S100A16 regulated the stability of ITGA3 mRNA via MOV10 to mediate ECM‑receptor interactions. In conclusion, S100A16 may bind to MOV10 to stabilize ITGA3 mRNA and regulate ECM‑receptor interactions, hence contributing to the malignant progression of LUAD.

Immune regulation and prognostic prediction model establishment and validation of PSMB6 in lung adenocarcinoma.

Lung cancer is one of the most common malignant tumors, and patients are often diagnosed at an advanced stage, posing a substantial risk to human health, so it is crucial to establish a model to forecast the prognosis of patients with lung cancer. Recent research has indicated that proteasome 20S subunit 6 (PSMB6) may be closely associated with anti-apoptotic pathways, and proliferation transduction signals in tumor cells of different tumors. However, the precise role of PSMB6 in the immunoregulatory processes within lung adenocarcinoma (LUAD) is yet to be elucidated. By analyzing the TCGA database, we discovered a positive correlation between the expression of PSMB6 and tumor growth trends, and lung adenocarcinoma patients with elevated PSMB6 expression levels had a worse prognosis. Our findings suggest a close correlation between PSMB6 expression levels, immune cell infiltration and immune checkpoint gene expression, which suggests that PSMB6 may become a new independent prognostic indicator. In addition, we developed a prognostic model of PSMB6-regulated immune infiltration-associated genes by analyzing the link between PSMB6 and the immune microenvironment. This model can not only predict the prognosis of lung adenocarcinoma but also forecasts the patient's reaction to immunotherapy. The validity of this research outcome has been confirmed by the GSE31210 and IMvigor210 cohorts. Analysis of the Kaplan-Meier Plotter database indicates that individuals with elevated levels of PSMB6 expression exhibit a poorer prognosis. Additionally, in vitro experiments demonstrated that knockdown of PSMB6 inhibits the proliferation, migration, and invasion of lung adenocarcinoma cells while promoting their apoptosis. Overall, our findings suggest that PSMB6 could remarkably influence the management and treatment of lung adenocarcinoma, opening new avenues for targeted immunotherapeutic strategies.

GALNT14-mediated O-glycosylation drives lung adenocarcinoma progression by reducing endogenous reactive oxygen species generation

Aberrant glycosylation, resulting from dysregulated expression of glycosyltransferases, is a prevalent feature of cancer cells. N-acetylgalactosaminyltransferase-14 (GALNT14) serves as a pivotal enzyme responsible for initiating O-GalNAcylation. It remains unclear whether and how GALNT14 affects lung adenocarcinoma (LUAD). Here, GALNT14 expression in LUAD was analyzed by searching public databases and verified by examining clinical samples. Bioinformatics, LC-MS/MS, RNA-seq, and RIP-seq analyses were used to uncover the mechanism underlying GALNT14. We observed that GALNT14 was frequently overexpressed in LUAD tissues. High GALNT14 expression was positively associated with advanced TNM stage, larger tumor size, and unfavorable prognosis. Functionally, GALNT14 facilitated LUAD cell proliferation, migration, and invasion in vitro and accelerated tumor growth in vivo. Mechanistically, GALNT14 reduced the accumulation of endogenous reactive oxygen species (ROS) to exert its oncogenic function via O-glycosylating hnRNPUL1 to upregulate AKR1C2 expression. Meanwhile, GALNT14 expression was directly modulated by miR-125a.These findings indicated that GALNT14-mediated O-GalNAcylation could drive LUAD progression via eliminating ROS and might be a valuable therapeutic target.

Oxidative stress gene signature construction to identify subtypes and prognosis of patients with lung adenocarcinoma

BackgroundAlthough oxidative stress and malignancies are intimately connected, it is unknown how lung adenocarcinoma (LUAD) is affected by oxidative stress response-related genes (OSRGs).Our goal in this work was to create a genetic signature based on OSRGs that might both predict prognosis and hint to potential treatment options for LUAD. MethodsClinicopathological and transcriptome information on LUAD patients was obtained from the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. A model for predicting risk was created using LASSO regression. The TCGA, GSE72094, and GSE41271 cohorts all demonstrated the risk model's prediction ability. Immune cell infiltration was measured using the CIBERSORT method, and the TIDE platform was implemented to evaluate the therapeutic efficacy of immune checkpoint inhibition (ICI). Chemotherapy sensitivity was predicted using drug activity data by the Genomics of Drug Sensitivity. An investigation into gene expression was conducted using qRT-PCR. CCK-8 and transwell assays were employed to look into how DKK1 affected the migration and proliferation of LUAD cells. ResultsA gene signature consisting of ANLN, FAM83A, DKK1, LOXL2, RHOV, IGFBP1, CCR2, GNG7, and C11orf16 was efficiently determined and used to calculate a patient-specific risk score, this functioned as a stand-alone biomarker for prediction. Correlations were found between risk scores and immune cell infiltration frequency, ICI therapy response rate, estimated chemotherapeutic drug susceptibility and autophagy-related genes.Furthermore, DKK1 knockdown reduced the ability of LUAD cells to multiply and migrate. ConclusionOur thorough transcriptome study of OSRGs generated a biological framework effective in forecasting outcome and responsiveness to therapy in LUAD patients.

Identification of potential biomarkers for lung adenocarcinoma: a study based on bioinformatics analysis combined with validation experiments.

The prognosis for lung adenocarcinoma (LUAD) remains dismal, with a 5-year survival rate of <20%. Therefore, the purpose of this study was to identify potentially reliable biomarkers in LUAD by machine learning combination with Mendelian randomization (MR). TCGA-LUAD, GSE40791, and GSE31210 were employed this study. Key module differential genes were identified through differentially expressed analysis and weighted gene co-expression network analysis (WGCNA). Furthermore, candidate biomarkers were derived from protein-protein interaction network (PPI) and machine learning. Ultimately, biomarkers were confirmed using MR analysis. In addition, immunohistochemistry was used to detect the expression levels of genes that have a causal relationship to LUAD in the LUAD group and the control group. Cell experiments were conducted to validate the effect of screening genes on proliferation, migration, and apoptosis of LUAD cells. The correlation between the screened genes and immune infiltration was determined by CIBERSORT algorithm. In the end, the gene-related drugs were predicted through the Drug-Gene Interaction database. In total, 401 key module differential genes were obtained by intersecting of 5,702 differentially expressed genes (DEGs) and 406 key module genes. Thereafter, GIMAP6, CAV1, PECAM1, and TGFBR2 were identified. Among them, only TGFBR2 had a significant causal relationship with LUAD (p=0.04, b=-0.06), and it is a protective factor for LUAD. Subsequently, sensitivity analyses showed that there were no heterogeneity and horizontal pleiotropy in the univariate MR results, and the results were not overly sensitive to individual SNP loci, further validating the reliability of univariate Mendelian randomization (UVMR) results. However, no causal relationship was found between them by reverse MR analysis. Meanwhile, TGFBR2 expression was decreased in LUAD group through immunohistochemistry. TGFBR2 can inhibit proliferation and migration of lung adenocarcinoma cell line A549 and promote apoptosis of A549 cells. Immune infiltration analysis suggested a potential link between TGFBR2 expression and immune infiltration. Finally, Irinotecan and Hesperetin were predicted through DGIDB database. In this study, TGFBR2 was identified as a biomarker of LUAD, which provided a new idea for the treatment strategy of LUAD and may aid in the development of personalized immunotherapy strategies.

Activin A inhibits the migration of human lung adenocarcinoma A549 cells induced by EGF

Activin A, a member of the transforming growth factor β (TGF-β) superfamily, is involved in tumorigenesis and tumor progression. However, it remains unclear whether activin A can affect the migration of lung adenocarcinoma (LUAD) cells. In this study, the results of differentially expressed genes (DEGs) identification revealed that lung adenocarcinoma tissues exhibited lower expression of activin βA mRNA, but higher expression of epidermal growth factor (EGF) and MMP9 mRNA compared to nontumor tissues. Moreover, we found that activin A inhibited human LUAD A549 cell proliferation promoted by EGF. Additionally, EGF induced A549 cell migration in microfluidic device, while activin A attenuated EGF actions. Simultaneously, EGF increased the levels of migration-related proteins, but activin A played the opposite role. Furthermore, the study revealed that EGF upregulated the ratio of p-ERK/ERK in A549 cells, which was weakened by activin A, and A549 cell migration regulated by activin A was not related to calcium signaling. In addition, the inhibitory effect of activin A on EGF-induced A549 cell migration was attenuated by the ERK inhibitor FR180204. These findings demonstrate that activin A effectively hinders the migration of A549 cells induced by EGF through ERK1/2 signaling, suggesting that targeting activin A may hold promise in the treatment of EGF-dependent LUAD growth and metastasis.

FHL2 expression by cancer-associated fibroblasts promotes metastasis and angiogenesis in lung adenocarcinoma.

Cancer-associated fibroblasts (CAFs) contribute to the progression of lung cancer. Four and a half LIM domain protein-2 (FHL2) is a component of focal adhesion structures. We analyzed the function of FHL2 expressed by CAFs in lung adenocarcinoma. Expression of FHL2 in fibroblast subtypes was investigated using database of single-cell RNA-sequencing of lung cancer tissue. The role of FHL2 in the proliferation and migration of CAFs was assessed. The effects of FHL2 knockout on the migration and invasion of human lung adenocarcinoma cells and tube formation of endothelial cells induced by CAF-conditioned medium (CM) were evaluated. The effect of FHL2 knockout in CAFs on metastasis was determined using a murine orthotopic lung cancer model. The prognostic significance of stromal FHL2 was assessed by immunohistochemistry in human adenocarcinoma specimens. FHL2 is highly expressed in myofibroblasts in cancer tissue. TGF-β1 upregulated FHL2 expression in CAFs and FHL2 knockdown attenuated CAF proliferation. FHL2 knockout reduced CAF induced migration of A110L and H23 human lung adenocarcinoma cell lines, and the induction of tube formation of endothelial cells. FHL2 knockout reduced CAF-induced metastasis of lung adenocarcinomas in an orthotopic model in vivo. The concentration of Osteopontin (OPN) in CM from CAF was downregulated by FHL2 knockout. siRNA silencing and antibody blocking of OPN reduced the pro-migratory effect of CM from CAF on lung cancer cells. In resected lung adenocarcinoma specimens, positive stromal FHL2 expression was significantly associated with higher microvascular density and worse prognosis. In conclusion, FHL2 expression by CAFs enhances the progression of lung adenocarcinoma by promoting angiogenesis and metastasis.

Sinensetin Inhibits Angiogenesis in Lung Adenocarcinoma via the miR-374c-5p/VEGF-A/VEGFR-2/AKT Axis.

Sinensetin is a product isolated from Orthosiphon aristatus, and its antitumor activities have been well established. This study focused on the role and mechanism of sinensetin in lung adenocarcinoma (LUAD). LUAD cells were treated with various concentrations of sinensetin. The proliferation, migration, invasion, and angiogenesis of LUAD cells were detected using colony formation, transwell, and tube formation assays, respectively. The protein levels of VEGF-A, VEGFR-2, and phosphorylated AKT (ser473) were measured by western blotting. The targeted relationship between VEGF-A and miR-374c-5p was verified by luciferase reporter assay. BALB/c nude mice inoculated with A549 cells were treated with sinensetin (40 mg/kg/day) by gavage for 21 days to investigate the effect of sinensetin on tumor growth and angiogenesis in vivo. We found that sinensetin reduced proliferation, migration, invasion, angiogenesis, and cancer stem characteristics of LUAD cells. Sinensetin also suppressed LUAD tumor growth and angiogenesis in vivo. Sinensetin downregulated VEGF-A expression in LUAD cells by enhancing miR-374c-5p expression. MiR-374c-5p inhibited the VEGF-A/VEGFR-2/AKT pathway in LUAD cells. The antitumor effect of sinensetin was reversed by overexpression of VEGF-A or inhibition of miR-374c-5p. Overall, sinensetin upregulates miR-374c-5p to inhibit the VEGF-A/VEGFR-2/AKT pathway, thereby exerting antitumor effect on LUAD.

Ropivacaine Administration Suppressed A549 Lung Adenocarcinoma Cell Proliferation and Migration via ACE2 Upregulation and Inhibition of the Wnt1 Pathway.

Previous studies have suggested that perioperative anesthesia could have direct impacts on cancer cell biology. The present study investigated the effects of ropivacaine administration on lung adenocarcinoma cells. Ropivacaine was administered to A549 cells at concentrations of 0.1, 1, and 6 mM for 2 h. Angiotensin-converting enzyme 2 (ACE2) small interfering RNA (siRNA) transfection was performed 6 h prior to ropivacaine administration. Cell proliferation and migration were assessed with cell counting kit 8 (CCK-8) and a wound healing assay at 0 and 24 h after anesthesia exposure. PCR arrays were performed, followed by PCR validation. Ropivacaine administration inhibited A549 cell proliferation and migration in a concentration-dependent manner, with ACE2 upregulation and HIF1α (hypoxia-inducible factor 1α) downregulation. The anticancer effect of ropivacaine was canceled out via ACE2 siRNA transfection. PCR arrays showed specific gene change patterns in the ropivacaine and respective ACE2-knockdown groups. EGFR (epidermal growth factor receptor), BAX (Bcl-2-associated X protein) and BCL2 (B-cell/CLL lymphoma 2) were suppressed with ropivacaine administration; these effects were reversed via ACE2 siRNA induction. Ropivacaine administration inhibited A549 cell biology in conjunction with ACE2 upregulation via the inhibition of the Wnt1 (wingless/Integrated 1) pathway.

6-Phosphogluconate dehydrogenase promotes glycolysis and fatty acid synthesis by inhibiting the AMPK pathway in lung adenocarcinoma cells

Abnormal metabolism has emerged as a prominent hallmark of cancer and plays a pivotal role in carcinogenesis and progression of lung adenocarcinoma (LUAD). In this study, single-cell sequencing revealed that the metabolic enzyme 6-phosphogluconate dehydrogenase (PGD), which is a critical regulator of the pentose phosphate pathway (PPP), is significantly upregulated in the malignant epithelial cell subpopulation during malignant progression. However, the precise functional significance of PGD in LUAD and its underlying mechanisms remain elusive. Through the integration of TCGA database analysis and LUAD tissue microarray data, it was found that PGD expression was significantly upregulated in LUAD and closely correlated with a poor prognosis in LUAD patients. Moreover, in vitro and in vivo analyses demonstrated that PGD knockout and inhibition of its activity mitigated the proliferation, migration, and invasion of LUAD cells. Mechanistically, immunoprecipitation-mass spectrometry (IP-MS) revealed for the first time that IQGAP1 is a robust novel interacting protein of PGD. PGD decreased p-AMPK levels by competitively interacting with the IQ domain of the known AMPKα binding partner IQGAP1, which promoted glycolysis and fatty acid synthesis in LUAD cells. Furthermore, we demonstrated that the combination of Physcion (a PGD-specific inhibitor) and metformin (an AMPK agonist) could inhibit tumor growth more effectively both in vivo and in vitro. Collectively, these findings suggest that PGD is a potential prognostic biomarker and therapeutic target for LUAD.

PLCG2, A Regulator of Lung Adenocarcinoma Proliferation and Migration Associated with Immune Infiltration.

Results from the TCGA database showed that phosphatidylinositol-specific phospholipase Cγ2 (PLCG2) expression level in Lung Adenocarcinoma (LUAD) was notably decreased compared to adjacent tissues, so we unveiled its role of LUAD. This study aims to explore the expression and clinical significance of Phosphatidyl-inositol-specific phospholipase Cγ2 (PLCG2) in lung adenocarcinoma (LUAD) cells and its role in cell proliferation and metastasis. Differential PLCG2 mRNA and protein levels between LUAD tissues and adjacent tissues were analyzed from the TCGA database, TIMER, and UALCAN database. Differentially expressed genes were screened for patients in the high and low PLCG2 mRNA expression groups by the R package as well as GSEA. The expression level of PLCG2 in LUAD cells was detected using qRT-PCR and CCK8, clone formation, Transwell, and Western blot assays. PLCG2 was lowly expressed in LUAD and did not significantly correlate with the prognosis of LUAD. PLCG2 expression levels varied significantly in terms of patients' gender, age, T, N, and pathological stage. GO/KEGG enrichment analysis showed that co-expression of PLCG2 was mainly associated with the immune response- regulating cell-surface receptors, and so on. GSEA analysis showed enrichment pathways of PLCG2-related differential gees were primarily associated with the olfactory transduction pathway, ribosome, etc. R software analysis revealed a significant correlation between PLCG2 expression and six types of immune-infiltrat-ing cells, positively correlated with immune checkpoint-related genes and negatively regulated by tumor mutational load. Overexpressing PLCG2 showed reduced LUAD cell proliferation, clone formation, cell migration and invasion, and epithelial-mesenchymal transition-associated proteins, compared with the control group. PLCG2 is lowly expressed in LUAD tissues and is involved in immune infiltration of LUAD, inhibiting LUAD cell proliferation and metastasis.

The role of tRF-Val-CAC-010 in lung adenocarcinoma: implications for tumorigenesis and metastasis

ObjectiveTransfer RNA-derived fragments (tRFs) are short non-coding RNA (ncRNA) sequences, ranging from 14 to 30 nucleotides, produced through the precise cleavage of precursor and mature tRNAs. While tRFs have been implicated in various diseases, including cancer, their role in lung adenocarcinoma (LUAD) remains underexplored. This study aims to investigate the impact of tRF-Val-CAC-010, a specific tRF molecule, on the phenotype of LUAD cells and its role in tumorigenesis and progression in vivo.MethodsThe expression level of tRF-Val-CAC-010 was quantified using quantitative real-time polymerase chain reaction (qRT-PCR). Specific inhibitors and mimics of tRF-Val-CAC-010 were synthesized for transient transfection. Cell proliferation was assessed using the Cell Counting Kit-8 (CCK-8), while cell invasion and migration were evaluated through Transwell invasion and scratch assays. Flow cytometry was utilized to analyze cell cycle and apoptosis. The in vivo effects of tRF-Val-CAC-010 on tumor growth and metastasis were determined through tumor formation and metastasis imaging experiments in nude mice.ResultsThe expression level of tRF-Val-CAC-010 was upregulated in A549 and PC9 LUAD cells (P < 0.01). Suppression of tRF-Val-CAC-010 expression resulted in decreased proliferation of A549 and PC9 cells (P < 0.001), reduced invasion and migration of A549 (P < 0.05, P < 0.001) and PC9 cells (P < 0.05, P < 0.01), enhanced apoptosis in both A549 (P < 0.05) and PC9 cells (P < 0.05), and increased G2 phase cell cycle arrest in A549 cells (P < 0.05). In vivo, the tumor formation volume in the tRF-inhibitor group was significantly smaller than that in the model and tRF-NC groups (P < 0.05). The metastatic tumor flux value in the tRF-inhibitor group was also significantly lower than that in the model and tRF-NC groups (P < 0.05).ConclusionThis study demonstrates that tRF-Val-CAC-010 promotes proliferation, migration, and invasion of LUAD cells and induces apoptosis in vitro, however, its specific effects on the cell cycle require further elucidation. Additionally, tRF-Val-CAC-010 enhances tumor formation and metastasis in vivo. Therefore, tRF-Val-CAC-010 may serve as a novel diagnostic biomarker and potential therapeutic target for LUAD.

IGFBP1 promotes the proliferation and migration of lung adenocarcinoma cells through the PPARα pathway

BackgroundThe immune status is closely linked to cancer progression, metastasis, and prognosis. Lipid metabolism, crucial for reshaping immune status, plays a key role in regulating the advancement of lung adenocarcinoma (LUAD) and deserves further investigation. MethodsThis study classifies LUAD patients into different immune subtypes based on lipid metabolism-related genes and compares the clinical characteristics among these subtypes. Single-multi COX analysis screens out key genes related to prognosis, and a risk feature and prognostic model are constructed. Cell cloning, scratch, transwell, western blotting and flow cytometry cell cycle analysis to detect the function of key genes. A subcutaneous tumor animal model is used to investigate the in vivo function and molecular mechanisms of key genes. ResultsLUAD patients are classified into three immune subtypes, among which C3 subtype has lower immune status and higher frequency of gene mutations, and show lower immunoreactivity in immunotherapy. COX analysis identified a prognostic model for four lipid metabolism factors (IGFBP1, NR0B2, PPARA, and POMC). IGFBP1, a core gene in this model, is highly expressed in the C3 subtype. Functionally, knocking down IGFBP1 significantly inhibits tumor cell cloning, scratch, and migration abilities, and downregulates the expression of cell cycle and EMT-related proteins. Knocking down IGFBP1 significantly inhibits tumor burden (P < 0.05). Mechanistically, knocking down IGFBP1 inhibits the activation of PPARα to regulate tumor cell growth. ConclusionsThis study found that lipid metabolism genes are closely related to LUAD, and IGFBP1 may be a key gene in regulating tumor growth and development.

METTL14-mediated m6A mRNA modification of G6PD promotes lung adenocarcinoma

METTL14 functions as an RNA methyltransferase involved in m6A modification, influencing mRNA biogenesis, decay, and translation processes. However, the specific mechanism by which METTL14 regulates glucose-6-phosphate dehydrogenase (G6PD) to promote the progression of lung adenocarcinoma (LUAD) is not well understood. Quantitative measurement and immunohistochemistry (IHC) analysis have demonstrated higher levels of m6A in LUAD tissues compared to adjacent normal tissues. Additionally, the expression of METTL14 was significantly increased in LUAD tissues. In LUAD cell lines, both METTL14 and m6A levels were elevated compared to normal human lung epithelial cells. Knockdown of METTL14 markedly reduced LUAD cell proliferation, migration, and invasion. Conversely, overexpression of METTL14, but not the mutant form, significantly enhanced these cellular processes in LUAD. In vivo studies using nude mice with subcutaneously transplanted LUAD cells demonstrated that stable METTL14 knockdown led to notably reduced tumor volume and weight, along with fewer Ki67-positive cells and lung metastatic sites. Importantly, METTL14 knockdown reduced glycolytic activity in LUAD cells. Through a combination of RNA sequencing and MeRIP-sequencing, we identified numerous altered genes and confirmed that IGF2BP2 enhances G6PD mRNA stability after METTL14-mediated m6A modification, thereby promoting tumor growth and metastasis. Moreover, LUAD patients with higher levels of G6PD had poorer overall survival (OS). In conclusion, our study indicates that METTL14 upregulates G6PD expression post-transcriptionally through an m6A-IGF2BP2-dependent mechanism, thereby stabilizing G6PD mRNA. These findings propose potential diagnostic biomarkers and effective targets for anti-metabolism therapy in LUAD.

MiR-137 mediated high expression of TIGD1 promotes migration, invasion, and suppresses apoptosis of lung adenocarcinoma

ObjectivesTigger transposable element-derived 1 (TIGD1) expression and its underlying functions and regulatory mechanisms in lung adenocarcinoma (LUAD) remain unknown. Therefore, we intended to explore the expression, potential functions, and regulatory mechanisms of TIGD1 in LUAD. Materials and methodsTIGD1 expression in LUAD tissues was determined by immunohistochemistry analysis of a tissue microarray. Functional experiments were conducted to determine how TIGD1 affects LUAD tumorigenesis and metastasis. The molecular mechanisms by which TIGD1 induces LUAD progression were determined. ResultsTIGD1 was upregulated in LUAD tissues and was related to lymph node metastases. TIGD1 knockdown suppressed LUAD cell proliferation, migration, and invasion, while promoted cell apoptosis. Furthermore, decreased metastatic nodules were observed in the TIGD1 knockdown mouse metastasis model. Moreover, microarray analysis was performed to determine the potential downstream genes of TIGD1 in LUAD. Hallmark pathway analysis revealed that the downstream genes of TIGD1 were involved in epithelial-mesenchymal transition (EMT). Western blotting confirmed that vimentin and TWIST was downregulated in TIGD1 knockdown cells, while E-cadherin was upregulated. Ingenuity pathway and hallmark pathway analyses revealed that TIGD1 regulated the interleukin-6 signaling pathway and related gene members. Western blotting, quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay indicated that downregulation of TIGD1 decreased interleukin-6 and CXCL1 expression. TIGD1 expression was negatively correlated with immune infiltration in LUAD. The upstream microRNA of TIGD1 was predicted, and subsequent luciferase reporter gene experiments confirmed the interactions between miR-137 and TIGD1. The expression of miR-137 was significantly downregulated in LUAD tissues and miR-137 suppressed the proliferation, migration, and invasion of LUAD cells, partially through negatively regulating the expression of TIGD1. ConclusionOur findings suggest that TIGD1, which was regulated by miR-137, contributed to LUAD progression by promoting cell proliferation, migration, invasion, and EMT and suppressing cell apoptosis.