DNA and Cell Biology

Morphological changes of podocyte mitochondria are observed in patients with mitochondrial cytopathy and nephrotic syndrome. However, whether mitochondrial dynamics involved in podocyte in lupus nephritis (LN) is still not clear. This study aims to investigate the associations between mitochondrial morphology and podocyte lesions and laboratory and pathological features in LN. The foot process width (FPW) and mitochondrial morphology were observed through electron microscope. Then the associations between mitochondrial morphology and podocyte lesions and laboratory features were explored in various International Society of Nephrology/Renal Pathology Society class LN patients. Foot process effacement and excessive mitochondria fission in podocyte were observed and proteinuria was positively correlated with FPW. Mitochondria area, circumference, and aspect ratio were negatively correlated with BUN, and 24h-UTP positively correlated with Alb. At the same time, Alb was negatively correlated with form factor. FPW, form factor, surface density, and numerical density on area were positively correlated with 24h-UTP. Excessive mitochondrial fission is associated with podocyte damage and proteinuria, whereas the mechanism still needs to be explored.

Alcohol use disorder (AUD) and cirrhosis are key outcomes of excessive alcohol use, and a genetic influence in these outcomes is increasingly recognized. While 80–90% of heavy alcohol users show evidence of fatty liver, only 10–20% progress to cirrhosis. There is currently no clear understanding of the causes of this difference in progression. The aim of this study is to evaluate genetics and epigenetics at the aldehyde dehydrogenase (ALDH2) locus in patients with AUD and liver complications. Study participants were inpatients from the clinical services of Gastroenterology and Psychiatry at St. John's Medical College Hospital (SJMCH) and the National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India. Men diagnosed as having AUD with cirrhosis (AUDC+ve, N = 136) and AUD without cirrhosis (AUDC−ve, N = 107) were assessed. FibroScan/sonographic evidence was used to rule out fibrosis in the AUDC−ve group. Genomic DNA was used for genotyping at the ALDH2 (rs2238151) locus. A subset of 89 samples was used for DNA methylation (AUDC+ve, N = 44; and AUDC−ve, N = 45) analysis at long interspersed nucleotide element 1 (LINE-1) and ALDH2 cytosine–phosphate–guanine (CpG) loci by pyrosequencing. ALDH2 DNA methylation was significantly lower in the AUDC+ve group compared with the AUDC−ve group (p < 0.001). Lower methylation was associated with a risk allele (T) of the ALDH2 locus (rs2238151) (p = 0.01). Global (LINE-1) DNA methylation levels were also significantly lower in the AUDC+ve group compared with the AUDC−ve group (p = 0.01). Compromised global methylation (LINE-1) and hypomethylation at the ALDH2 gene was observed in patients with cirrhosis compared with those without cirrhosis. DNA methylation could be explored as a biomarker for cirrhosis and liver complications.

Infiltrated immune cells are an important constitute of tumor microenvironment, which exert complex effects on gastric cancer (GC) pathogenesis and progression. By using weighted gene co-expression network analysis, integrating the data from The Cancer Genome Atlas-stomach adenocarcinoma and GSE62254, we identify Aldo-Keto Reductase Family 1 Member B (AKR1B1) as a hub gene for immune regulation in GC. Notably, AKR1B1 is associated with higher immune infiltration and worse histologic grade of GC. In addition, AKR1B1 is an independent factor for predicting the survival rate of GC patients. In vitro experiments further demonstrated that AKR1B1-overexpressed THP-1-derived macrophages promoted the proliferation and migration of GC cells. Taken together, AKR1B1 plays an important role in GC progression by regulating immune microenvironment, which could be a biomarker for predicting GC prognosis as well as a potential therapeutic target for GC treatment.

Nonsyndromic cleft lip with or without cleft palate (NSCL/P) is a common craniofacial birth defect with complex etiologies. Recently, the dysregulation of long noncoding RNAs (lncRNAs) has been implicated in many developmental diseases, including NSCL/P. However, the functions and mechanisms of lncRNAs in NSCL/P have not been fully elucidated. In this study, we found that lncRNA MIR31HG in NSCL/P patients was significantly downregulated than that in healthy individuals (GSE42589, GSE183527). In addition, single nucleotide polymorphism rs58751040 in MIR31HG was nominally associated with NSCL/P susceptibility (odds ratio: 1.29, 95% confidence interval: 1.03–1.54, p = 4.93 × 10⁻²) through a case–control study (504 NSCL/P cases and 455 controls). Luciferase activity assay showed that the C allele of rs58751040 revealed a decreased transcription activity of MIR31HG than the G allele. Moreover, knockdown of MIR31HG promoted cell proliferation and migration in human oral keratinocytes and human embryonic palate mesenchyme. Bioinformatic analysis and cellular studies suggested that MIR31HG may confer susceptibility to risk of NSCL/P through matrix Gla protein (MGP) signaling. In summary, we identified a novel lncRNA involved in the development of NSCL/P.

Circular RNAs (circRNAs) are generally formed by the back-splicing of precursor mRNA. Increasing evidence implicates the important role of circRNAs in cardiovascular diseases. However, the role of circ-insulin-like growth factor 1 receptor (circIGF1R) in cardiomyocyte (CM) proliferation remains unclear. Here, we investigated the potential role of the circIGF1R in the proliferation of CMs. We found that circIGF1R expression in heart tissues and primary CMs from adult mice was significantly lower than that in neonatal mice at postnatal 1 day (p1). Increased circIGF1R expression was detected in the injured neonatal heart at 0.5 and 1 days post-resection. circIGF1R knockdown significantly decreased the proliferation of primary CMs. Combined prediction software, luciferase reporter gene analysis, and quantitative real time-PCR (qPCR) revealed that circIGF1R interacted with miR-362-5p. A significant increase in miR-362-5p expression was detected in the adult heart compared with that in the neonatal heart. Further, heart injury significantly decreased the expression of miR-362-5p in neonatal mice. Treatment with miR-362-5p mimics significantly suppressed the proliferation of primary CMs, whereas knockdown of miR-362-5p promoted the CMs proliferation. Meanwhile, miR-362-5p silencing can rescue the proliferation inhibition of CMs induced by circIGF1R knockdown. Target prediction and qPCR validation revealed that miR-362-5p significantly inhibited the expression of Phf3 in primary CMs. In addition, decreased Phf3 expression was detected in adult hearts compared with neonatal hearts. Consistently, increased Phf3 expression was detected in injured neonatal hearts compared with that in sham hearts. Knockdown of Phf3 markedly repressed CMs proliferation. Taken together, these findings suggest that circIGF1R might contribute to cardiomyocyte proliferation by promoting Pfh3 expression by sponging miR-362-5p and provide an important experimental basis for the regulation of heart regeneration.

The full name of the FTO gene is fat mass and obesity-associated gene. In recent years, it has also been found that FTO is involved in m6A demethylation and regulates the progression of multiple cancers, including gastric cancer. The cancer stem cell theory argues that cancer stem cells are key factors in cancer metastasis, and inhibiting the expression of stemness genes is a good method to inhibit metastasis of gastric cancer. Currently, the role of the FTO gene in regulating stemness of gastric cancer cells is still unclear. By analyzing public databases, it was discovered that FTO gene expression was increased in gastric cancer, and high expression of FTO was associated with poor prognosis of patients with gastric cancer. After gastric cancer stem cells were isolated, it was found that FTO protein expression was increased in gastric cancer stem cells; stemness of gastric cancer cells was reduced after the FTO gene knockdown; subcutaneous tumors of nude mice were smaller than those of the control group after FTO knockdown; and stemness of gastric cancer cells was enhanced after FTO was overexpressed by plasmid. By reviewing additional literature and experimental validation, we found that SOX2 may be the factor by which FTO promotes the stemness of gastric cancer cells. Therefore, it was concluded that FTO could promote the stemness of gastric cancer cells, and targeting FTO may be a potential therapeutic approach for patients with metastatic gastric cancer.

CTR number: TOP-IACUC-2021-0123

Laryngeal squamous cell carcinoma (LSCC) is the most common and prevalent malignant tumor in head and neck squamous cell carcinoma. Recent studies have shown that circular RNAs (circRNAs) play a vital role in cancer development, but their specific role in the tumorigenesis and development of LSCC remains unclear. We selected five pairs of LSCC tumor tissues and paracancerous tissues for RNA sequencing. Reverse transcription-quantitative PCR (RT-qPCR), Sanger sequencing, and fluorescence in situ hybridization were utilized to study the expression, localization, and clinical significance of circTRIO in LSCC tissues, and TU212 and TU686 cell lines. Furthermore, cell counting Kit-8, colony-forming assay, Transwell, and flow cytometry assays were assessed to illustrate the crucial role played by the circTRIO in proliferation, colony-forming ability, migration, and apoptosis in LSCC cells. Finally, the molecule's role as a microRNA (miRNA) sponge was analyzed. In the results, we screened out a promising upregulated novel circRNA-circTRIO in LSCC tumor tissues compared with paracancerous tissues using RNA sequencing. Then, we used qPCR to evaluate the expression of circTRIO in 20 additional paired LSCC tissues and two cells, and the results showed that circTRIO was highly expressed in LSCC and that this high expression was closely related to the malignant progression of LSCC. Furthermore, we examined circTRIO expression in the Gene Expression Omnibus data sets GSE142083 and GSE27020, and circTRIO expression was considerably higher in tumor tissues compared with the adjacent tissues. Kaplan–Meier survival analysis showed that the expression of circTRIO was associated with worse disease-free survival. The Gene Set Enrichment Analysis biological pathway evaluation results demonstrated that circTRIO was mainly enriched in cancer pathways. Moreover, we confirmed that silencing circTRIOs can help to significantly inhibit LSCC cell proliferation and migration while triggering apoptosis. Upregulated circTRIO expression levels may play an important role in the tumorigenesis and development of LSCC.

Tumor microenvironment has significant influence in therapeutic response and clinical outcome. Combination therapy is more effective in cancer treatment compared with monotherapy. Any chemical or drug that targets tumor microenvironment pathway, will be a boon to combination cancer chemotherapy. Combination therapy through micronutrient may have added advantage in clinical applications. Selenium (Se) is an essential micronutrient; Se in the form of Se nanoparticles (SeNPs) show efficient anticancer properties and may have the potential to target tumor niche such as hypoxic environment. The aim of this study was to find out the anticancer effect of SeNPs on cell line HepG2 under hypoxic condition and also to evaluate their effect on the translocation of hypoxia-inducible factors (HIFs) from cytoplasm to nucleus that help the cells to survive under hypoxic condition. It was found that the SeNPs induce HepG2 cell death in normoxic and hypoxic conditions, however, hypoxic condition showed higher LD₅₀. SeNP concentration is directly proportional to cell death in both the conditions. Furthermore, intracellular accumulation of Se is not affected by hypoxia. SeNP-induced HepG2 cell death is due to increased DNA damage, nuclear condensation, and mitochondrial membrane potential disturbance. Furthermore, SeNPs were also found to decrease the translocation of HIFs from cytosol to the nucleus. After analyzing the results, it is concluded that SeNP treatment disturbs tumor niche through the inhibition of HIFs' translocation from cytosol to nucleus. SeNPs in synergy with primary drug, such as doxorubicin (DOX), may enhance the anticancer efficacy of DOX through regulation of HIFs, warranting further research.