Expression of the Vesicular Monoamine Transporter Gene Solute Carrier Family 18 Member 1 (SLC18A1) in Lung Cancer

Associations between methamphetamine use disorder and SLC18A1, SLC18A2, BDNF, and FAAH gene sequence variants and expression levels

INTRODUCTION

Assessing candidate gene sequence variations and expression helps to understand methamphetamine use disorder and inform potential treatments. We investigated single nucleotide polymorphisms (SNPs) and gene expression in four candidate genes: SLC18A1, SLC18A2, BDNF, and FAAH, between controls and people with methamphetamine use disorder.

METHODS

Fifty-nine participants (29 people with methamphetamine use disorder and 30 controls) completed a clinical interview, cognitive tasks, and provided a blood sample. SLC18A1, SLC18A2, BDNF, and FAAH SNPs were genotyped, and gene expression was assessed with real-time quantitative PCR.

RESULTS

SLC18A1 Pro4Thr was associated with methamphetamine use disorder (OR = 6.22; p = .007). SLC18A2 variants, rs363227 and rs363387, were negatively associated with methamphetamine use severity (p = .003) and positively associated with inhibitory control performance (p = .006), respectively. BDNF Val66Met was associated with the severity of use (p = .008). SLC18A2 and FAAH mRNA levels were lower in people who use methamphetamine relative to controls (p = .021 and .010, respectively).

CONCLUSIONS

SLC18A1 is identified for the first time to play a potential role in methamphetamine use disorder. Lower levels of blood SLC18A2 and FAAH mRNA in people with methamphetamine use disorder suggest reduced monoamine reuptake, recycling, or release, and higher anandamide levels in this clinical group, which may be potential therapeutic targets.

Decreased SLC16A13 Expression Level Can Increase Apoptosis in KATO2 Cell Line, A Promising Biomarker

OBJECTIVE

Gastric cancer is a prevalent cancer type worldwide, and significant research efforts are focused on finding effective treatments. Recent studies have highlighted the importance of plasma membrane carriers, particularly solute carriers, in cancer progression. The SLC16A family, notably the SLC16A13 gene, plays a critical role in cancer development and tumor growth. This study aims to explore the impact of reducing SLC16A13 expression in gastric cancer cells on their survival, proliferation, and metastatic potential.

METHODS

Gastric cancer cells (KATO2) were cultured in RPMI medium supplemented with 10% fetal bovine serum. The cells were then transfected with SLC16A13 si-RNA to lower gene expression. The effects of this si-RNA on cell death and apoptosis were assessed using MTT and flow cytometry assays. Cell migration capabilities were evaluated using the scratch test. Western blot and Real-Time PCR were employed to measure SLC16A13 expression levels and protein detection. Additionally, RT-PCR was used to analyze changes in genes related to apoptosis and cell migration.

RESULTS

The reduction of SLC16A13 expression following si-RNA transfection significantly increased apoptosis and cell death in the KATO2 cell line after 72 hours (P < 0.0001). Furthermore, the study revealed that decreased SLC16A13 expression did not impact cancer cell migration. Cell viability, assessed by MTT assay, showed a significant decrease at 48 and 72 hours post-transfection (P < 0.0001).

CONCLUSION

The findings indicate that targeting SLC16A13 can effectively increase cell death and apoptosis in gastric cancer cells, making it a viable therapeutic target.

A Systematic Pan-Cancer Analysis of MEIS1 in Human Tumors as Prognostic Biomarker and Immunotherapy Target

BACKGROUND

We intended to explore the potential immunological functions and prognostic value of Myeloid Ecotropic Viral Integration Site 1 (MEIS1) across 33 cancer types.

METHODS

The data were acquired from The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx) and Gene expression omnibus (GEO) datasets. Bioinformatics was used to excavate the potential mechanisms of MEIS1 across different cancers.

RESULTS

MEIS1 was downregulated in most tumors, and it was linked to the immune infiltration level of cancer patients. MEIS1 expression was different in various immune subtypes including C2 (IFN-gamma dominant), C5 (immunologically quiet), C3 (inflammatory), C4 (lymphocyte depleted), C6 (TGF-b dominant) and C1 (wound healing) in various cancers. MEIS1 expression was correlated with Macrophages_M2, CD8+T cells, Macrophages_M1, Macrophages_M0 and neutrophils in many cancers. MEIS1 expression was negatively related to tumor mutational burden (TMB), microsatellite instability (MSI) and neoantigen (NEO) in several cancers. Low MEIS1 expression predicts poor overall survival (OS) in adrenocortical carcinoma (ACC), head and neck squamous cell carcinoma (HNSC), and kidney renal clear cell carcinoma (KIRC) patients, while high MEIS1 expression predicts poor OS in colon adenocarcinoma (COAD) and low grade glioma (LGG) patients.

CONCLUSION

Our findings revealed that MEIS1 is likely to be a potential new target for immuno-oncology.

Identification of a Six-Gene SLC Family Signature With Prognostic Value in Patients With Lung Adenocarcinoma

Given the importance of solute carrier (SLC) proteins in maintaining cellular metabolic homeostasis and that their dysregulation contributes to cancer progression, here we constructed a robust SLC family signature for lung adenocarcinoma (LUAD) patient stratification. Transcriptomic profiles and relevant clinical information of LUAD patients were downloaded from the TCGA and GEO databases. SLC family genes differentially expressed between LUAD tissues and adjacent normal tissues were identified using limma in R. Of these, prognosis-related SLC family genes were further screened out and used to construct a novel SLC family-based signature in the training cohort. The accuracy of the prognostic signature was assessed in the testing cohort, the entire cohort, and the external GSE72094 cohort. Correlations between the prognostic signature and the tumor immune microenvironment and immune cell infiltrates were further explored. We found that seventy percent of SLC family genes (279/397) were differentially expressed between LUAC tissues and adjacent normal. Twenty-six genes with p-values < 0.05 in univariate Cox regression analysis and Kaplan-Meier survival analysis were regarded as prognosis-related SLC family genes, six of which were used to construct a prognostic signature for patient classification into high- and low-risk groups. Kaplan-Meier survival analysis in all internal and external cohorts revealed a better overall survival for patients in the low-risk group than those in the high-risk group. Univariate and multivariate Cox regression analyses indicated that the derived risk score was an independent prognostic factor for LUAD patients. Moreover, a nomogram based on the six-gene signature and clinicopathological factors was developed for clinical application. High-risk patients had lower stromal, immune, and ESTIMATE scores and higher tumor purities than those in the low-risk group. The proportions of infiltrating naive CD4 T cells, activated memory CD4 T cells, M0 macrophages, resting dendritic cells, resting mast cells, activated mast cells, and eosinophils were significantly different between the high- and low-risk prognostic groups. In all, the six-gene SLC family signature is of satisfactory accuracy and generalizability for predicting overall survival in patients with LUAD. Furthermore, this prognostics signature is related to tumor immune status and distinct immune cell infiltrates in the tumor microenvironment.

Effect of myeloid ecotropic viral integration site (MEIS) family genes on tumor microenvironment remodeling and its potential therapeutic effect

BACKGROUND

The myeloid ecotropic viral integration site (MEIS) family of genes is related to the occurrence, development, and outcome of many cancers. However, its role in the immune and tumor microenvironment (TME) is unclear. This study explored the relationship between the expression of MEIS genes and patient survival, immune subtypes, TME, tumor stem cell correlation, and drug sensitivity in cancer.

METHODS

We used The Cancer Genome Atlas pan-cancer data to analyze the expression of the MEIS family genes. Kaplan-Meier analysis and univariate Cox proportional hazard regression model were used to detect the relationship between gene expression and overall survival. Analysis of variance was used to explore the relationship between the MEIS family and the immune components in the tumor, and the ESTIMATE algorithm was used to calculate the proportion and level of tumor-infiltrating immune cells. Spearman and Pearson's correlation tests were carried out to detect the relationship between MEIS and the characteristics of tumor stem cells and drug sensitivity.

RESULTS

The MEIS family of genes shows different expression profiles in different cancers, with substantial inter- and intra-cancer heterogeneity. Among them, MEIS3 was upregulated in most cancers, whereas MEIS2 was downregulated. The change in MEIS gene expression was usually related to overall survival, but whether a member of the MEIS family was a risk factor or a protective factor was cancer-dependent. Immune component analysis suggested that the role of MEIS genes in promoting or inhibiting cancer may be related to different degrees of immune silencing. Further, there were varying degrees of correlation between MEIS gene expression and cancer cell stemness characteristics. It was also found that MEIS genes, especially MEIS1 and MEIS2, may be related to chemotherapy resistance.

CONCLUSIONS

We explored the expression, prognostic relationship, molecular characteristics, and effects on immunity and TME of the MEIS gene family in cancer. Our results suggest that MEIS members should be studied as independent entities in different types of cancer. The MEIS gene family may be a potential target for cancer therapy, but further experiments are needed to confirm this.