Fibrillarin promotes homologous recombination repair by facilitating the recruitment of recombinase RAD51 to DNA damage sites. / çº¤ç»´è›‹ç™½é€šè¿‡ä¿ƒè¿›é‡ç»„é ¶RAD51在DNA损伤位点的招募参与同源重组修复.

Eukaryotic organisms constantly face a wide range of internal and external factors that cause damage to their DNA. Failure to accurately and efficiently repair these DNA lesions can result in genomic instability and the development of tumors (Canela et al., 2017). Among the various forms of DNA damage, DNA double-strand breaks (DSBs) are particularly harmful. Two major pathways, non-homologous end joining (NHEJ) and homologous recombination (HR), are primarily responsible for repairing DSBs (Katsuki et al., 2020; Li and Yuan, 2021; Zhang and Gong, 2021; Xiang et al., 2023). NHEJ is an error-prone repair mechanism that simply joins the broken ends together (Blunt et al., 1995; Hartley et al., 1995). In contrast, HR is a precise repair process. It involves multiple proteins in eukaryotic cells, with the RAD51 recombinase being the key player, which is analogous to bacterial recombinase A (RecA) (Shinohara et al., 1992). The central event in HR is the formation of RAD51-single-stranded DNA (ssDNA) nucleoprotein filaments that facilitate homology search and DNA strand invasion, ultimately leading to the initiation of repair synthesis (Miné et al., 2007; Hilario et al., 2009; Ma et al., 2017).

Corrigendum: Whole transcriptome profiling of the effects of cadmium on the liver of the Xiangxi yellow heifer.

[This corrects the article DOI: 10.3389/fvets.2022.846662.].

Whole Transcriptome Profiling of the Effects of Cadmium on the Liver of the Xiangxi Yellow Heifer.

Cadmium (Cd) is a major heavy metal toxicant found in industrial zones. Humans and animals are exposed to it through their diet, which results in various physiological problems. In the current study, the toxic effects of Cd on the liver were investigated by whole-transcriptome sequencing (RNA-seq) of the livers of Xiangxi heifers fed a diet with excess Cd. We randomly divided six healthy heifers into two groups. The first group received a control diet, whereas the second group received Cd-exceeding diets for 100 days. After 100 days, the livers were collected. A total of 551 differentially expressed mRNAs, 24 differentially expressed miRNAs, and 169 differentially expressed lncRNAs were identified (p < 0.05, |log2FC| >1). Differentially expressed genes (DEGs) were analyzed by gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses. We found that under Cd exposure, DEGs were enriched in the adenosine 5'-monophosphate-activated protein kinase pathway, which is involved in autophagy regulation, and the peroxisome proliferator-activated receptor pathway, which is involved in lipid metabolism. In addition, the apolipoprotein A4 gene, which has anti-inflammatory and antioxidant effects, the anti-apoptotic gene ATPase H+/K+ transporting the nongastric alpha2 subunit, and the cholesterol metabolism-associated gene endothelial lipase gene were significantly downregulated. C-X-C motif chemokine ligand 3, cholesterol 7α-hydroxylase, and stearoyl-CoA desaturase, which are involved in the development of fatty liver, were significantly upregulated. These genes revealed the main effects of Cd on the liver of Xiangxi yellow heifers. The current study provides insightful information regarding the DEGs involved in autophagy regulation, apoptosis, lipid metabolism, anti-inflammation, and antioxidant enzyme activity. These may serve as useful biomarkers for predicting and treating Cd-related diseases in the future.

Follicular fluid exosomes: Important modulator in proliferation and steroid synthesis of porcine granulosa cells.

Granulosa cells (GCs) are regulated by various factors during ovarian development. However, there are few reports on the role of follicular fluid exosomes in ovarian GCs. In this study, porcine ovarian GCs were used to explore the effects of follicular fluid exosomes on GCs. GCs were treated with in vitro, and the changes in cell proliferation, steroid synthesis, and associated signal pathways were detected. The results showed that exosomes increased cell viability and altered the gene expression profile of GCs. Exosomes also increased the level of gene expression associated with both proliferation and progesterone synthesis, in which the MAPK/ERK and WNT/B-CATENIN pathways were involved. In addition, exosome-carried microRNAs were identified by high-throughput sequencing, and exosomal miR-31-5p was found to promote the proliferation of GCs and progesterone synthesis via the WNT/B-CATENIN pathway by targeting the SFRP4 follicle growth inhibitor. In conclusion, this study has demonstrated that exosomes are essential substances involved in regulating the physiological function of GCs.

THAP11 Functions as a Tumor Suppressor in Gastric Cancer through Regulating c-Myc Signaling Pathways.

We aim to investigate the role of THAP11 (thanatos-associated protein11) in gastric cancer and its regulation mechanisms. THAP11 expression was analyzed in 51 pairs of GC tissues and the corresponding paracancerous tissues by qRT-PCR and Western blot. After THAP11 was overexpressed or knocked-down, cell proliferation, cell cycle, and apoptosis were detected in MKN-45 cells. We found that THAP11 was significantly downregulated in GC tissues and GC cell lines. Functionally, THAP11 overexpression markedly inhibited cell growth, induced G1/G0 cell-cycle arrest, and promoted cell apoptosis of MKN-45 cells, while silencing of THAP11 led to increased cell growth, increased DNA synthesis, and inhibited apoptosis. In addition, THAP11 negatively regulated the expression of c-Myc, decreased cyclinD1 protein, and increased p27 and p21 protein levels. We also found cell growth suppression induced by THAP11 was rescued by c-Myc overexpression, further confirming that THAP11 suppresses gastric cancer cell growth via the c-Myc pathway. THAP11 acts as a cell growth suppressor and exerts its role possibly through negatively regulating c-Myc pathway in gastric cancer.

Nei Endonuclease VIII-Like1 (NEIL1) Inhibits Apoptosis of Human Colorectal Cancer Cells.

The study is aimed at investigating the role of Nei endonuclease VIII-like1 (NEIL1) in the pathogenesis of colorectal cancer (CRC). The human CRC (HCT116 and SW480) cells were subjected to the siRNA silencing and recombinant plasmid overexpression of NEIL1. Transfection of siNEIL1 significantly inhibited the cell growth. It also increased the Bax expression levels, while it decreased the Bcl-2 expression levels in human CRC cells, leading the Bax/Bcl-2 balance toward apoptosis. Moreover, the apoptosis was promoted through the caspase-9 signaling pathway. One the other hand, high expression of NEIL1 promoted the cell viability and reduced the apoptosis, inducing the balance of Bax/Bcl-2 in the human colon cancer cells to be antiapoptotic. In addition, the caspase-9 signaling pathway inhibited apoptosis, contrary to the results obtained by downregulating NEIL1 expression. Furthermore, NEIL1 was negatively regulated by miR-7-5p, indicating that miR-7-5p inhibited the NEIL1 expression after transcription. Overexpression of miR-7-5p reversed the effects of NEIL1 on these CRC cells. In conclusion, NEIL1 promotes the proliferation of CRC cells, which is regulated negatively by miR-7-5p. These findings suggest that NEIL1 is a potential therapeutic target for CRC.

Effect of nerve growth factor on the proliferation in newborn bovine testicular Sertoli cells.

Nerve growth factor (NGF) has been proved to play important roles in male reproductive physiology, but the molecular mechanisms of NGF action remain unclear. In this study, the effects of NGF on the growth of newborn bovine testicular Sertoli (NBS) cells and the related signaling pathways were investigated. The NBS cells were treated in vitro with NGF (100 ng/mL) for 18 h. The expression levels of cell proliferation related genes, INHBB, and cytoplasmic specialization related gene were determined using real-time PCR and Western blot. The roles of PI3K/AKT and MAPK/ERK pathways in NGF-induced cell proliferation were investigated. It was found that NGF regulates proliferation and function of NBS cells via its receptor NTRK1 by activating the PI3K/ATK and MAPK/ERK signaling pathways. The study will help to further understand the role of NGF in male reproduction and provide new therapeutic targets for reproductive dysfunctions in male animals.

MicroRNA-145 suppresses gastric cancer progression by targeting Hu-antigen R.

Hu-antigen R (HuR) is involved in the carcinogenesis and progression of multiple types of cancer. However, its precise role in gastric cancer (GC) and the relevant molecular mechanism remain largely unclear. In the present study, we found that HuR expression level was higher in GC tissues and cell lines than in adjacent normal tissues and normal gastric epithelial cell lines, and this elevated expression was found to have a significant association with lymph node metastasis. Moreover, silencing HuR with RNA interference inhibited cell viability and induced cell apoptosis through the apoptosis-related regulators (Bcl-2 and Bax) in GC cells. In addition, bioinformatic analysis revealed that HuR expression was inversely correlated with miR-145 expression in GC tissue samples, and HuR was identified as a direct target of miR-145 with the dual-luciferase reporter. Enforced expression of miR-145 inhibited the HuR expression at both mRNA and protein levels and induced similar biologic effects of silencing HuR in GC cells. Additionally, we also found that restoration of HuR could eliminate the effects induced by miR-145 in GC cells. Taken together, these findings demonstrate the exact role of the miR-145-HuR axis in the progression of GC and indicate a potential target for GC therapy.

MicroRNA-497-5p Induces Cell Cycle Arrest Of Cervical Cancer Cells In S Phase By Targeting CBX4.

PURPOSE: miR-497-5p can inhibit cervical cancer cell proliferation. However, the underlying mechanism remains to be elucidated. METHODS: Bioinformatics was used to analyze the target genes of miR-497-5p. qRT-PCR and Western blot were used to analyze mRNA and protein expression, respectively. Dual-luciferase reporter assay was used to analyze the direct binding between miR-497-5p and 3'-untranslated region of CBX4. Cell viability was measured with MTT assay. Flow cytometry was performed to detect cell cycle distribution. RESULTS: Here, using bioinformatics methods we firstly found that miR-497-5p regulated cervical carcinoma proliferation by targeting polycomb chromobox4 (CBX4). Expression of miR-497-5p in cervical carcinoma tissues was negatively correlated with CBX4. A binding region of miR-497-5p in 3'-untranslated region of CBX4 was predicted. Further experiments confirmed that miR-497-5p directly targeted CBX4. Besides, RNA interference of CBX4 inhibited cervical cancer cell proliferation, arrested cells at S phase and reduced the expression of CDK2 and Cyclin A2 proteins. The use of miR-497-5p inhibitor compromised CBX4 interference RNAs induced cycle arrest of cervical cancer cells. Cells co-transfected with miR-497-5p inhibitors and CBX4 interference RNAs had a higher proliferation rate than CBX4 inference RNA-transfected cells. CONCLUSION: All together, the present study demonstrates that miR-497-5p inhibits cervical cancer cells proliferation by directly targeting CBX4.

The effect of MTHFD2 on the proliferation and migration of colorectal cancer cell lines.

PURPOSE: Methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) is a tetramethylfolate dehydrogenase enzyme involved in folate metabolism. The aim of this study is to determine the effect of MTHFD2 on the proliferation and metastasis of colorectal cancer (CRC). PATIENTS AND METHODS: MTHFD2 was silenced or overexpressed in CRC cells. qRT-PCR and Western blotting were used to analyze mRNA and protein expression, respectively. The MTT assay and colony forming assay were used to detect cell proliferation and colony formation ability. The cycle and apoptosis changes were detected by flow cytometry. Transwell experiments were used to analyze the migration ability of CRC cells. RESULTS: The expression of MTHFD2 in 31 kinds of cancers was analyzed by bioinformatics, and MTHFD2 was found highly expressed in various cancer cells including CRC cells. Silencing the expression of MTHFD2 resulted in inhibition of the proliferation of CRC cells, weakening of the migration ability, blocking of the cell cycle in G0/G1-S phase, and promotion of the apoptosis of CRC cells. On the contrary, overexpression of MTHFD2 in CRC cells resulted in enhancement of the proliferation and migration ability, promotion of cell cycle progression and inhibition of cell apoptosis. CONCLUSION: MTHFD2 is positively related with colorectal cancer and the MTHFD2 gene is a tumor promoting gene in CRC cells.

Effect of mGluR7 on proliferation of human embryonic neural stem cells.

This study is to investigate the effect of metabotropic glutamate receptor 7 (mGluR7) on the proliferation of human embryonic neural stem cells (NSCs) and its molecular mechanism.Human embryonic NSCs were isolated. The pCMV2-GV146-GFP-mGluR7 plasmid was transfected to over-express mGluR7 while mGluR7 siRNA was transfected to knockdown mGluR7. MTT assay was used to analyze cell proliferation. Flow cytometry was used to detect cell cycle and apoptosis. Protein and mRNA levels were analyzed by Western blot and RT-qPCR, respectively.The viability of human NSCs and the diameter of neurospheres after 24 hours, 48 hours, and 72 hours of transfection significantly increased by mGluR7 overexpression whereas significantly decreased by mGluR7 knockdown. Ki-67 expression was up-regulated by mGluR7 overexpression whereas down-regulated by mGluR7 siRNA, indicating a promotive effect of mGluR7 on NSC proliferation. After mGluR7 overexpression, G1/G0 phase cell ratio dropped significantly compared with control group, while the S phase cell ratio increased. mGluR7 silencing arrested human NSCs at G1/G0 phase. After 48 hours of transfection, there was a decrease of apoptosis by mGluR7 overexpression, while mGluR7 silencing induced apoptosis of human NSCs. Additionally, overexpression of mGluR7 up-regulated the expression of p-serine/threonine kinase (AKT), cyclin D1, and cyclin-dependent kinase 2 (CDK2). The mGluR7 knockdown had opposite effects. Similarly, mGluR7 down-regulated the expression of Caspase-3/9, while the mGluR7 knockdown promoted this.mGluR7 can promote the proliferation of human embryonic cortical NSCs in vitro. This effect may be mediated by promoting cell cycle progression, inhibiting cell apoptosis, activating the AKT signaling pathway, and inhibiting the Caspase-3/9 signaling pathway.

Effect and mechanism of mGluR6 on the biological function of rat embryonic neural stem cells.

Here, we investigated the effects and molecular mechanisms of metabotropic glutamate receptor 6 (mGluR6) on rat embryonic neural stem cells (NSCs). Overexpression of mGluR6 significantly promoted the proliferation of NSCs and increased the diameter of neutrospheres after treatment for 24 h, 48 h and 72 h. Overexpression of mGluR6 promoted G1 to S phase transition, with significantly decreased cell ratio in G1/G0 phase but significantly increased cell ratio in S phase. Additionally, mGluR6 overexpression for 48 h decreased the early and late apoptosis significantly. Moreover, overexpression of mGluR6 significantly increased the expression of p-ERK1/2, Cyclin D1 and CDK2, while the expression of p-p38 was significantly decreased. On the contrary, these effects of mGluR6 overexpression were reversed by mGluR6 knockdown. In conclusion, mGluR6 promotes the proliferation of NSCs by activation of ERK1/2-Cyclin D1/CDK2 signaling pathway and inhibits the apoptosis of NSCs by blockage of the p38 MAPK signaling pathway.

Proteomic Screening for Serum Biomarkers for Cervical Cancer and Their Clinical Significance.

BACKGROUND The present study aimed to determine serum markers for cervical cancer (CC) and to provide valuable references for clinical diagnosis and treatment. MATERIAL AND METHODS Serum samples were collected from age-matched healthy control women, and from female CC patients before and after surgery. Serum biomarkers were selected by comparing serum peptides profiles among the 3 groups by magnetic bead-based weak cation - exchange chromatography fractionation combined with matrix-assisted laser desorption/ionization-time of flight mass spectrometry. Probable serum biomarkers for cervical cancer were then further identified by liquid chromatography-electrospray ionization-tandem mass spectrometry system and the identified proteins were verified by enzyme-linked immunosorbent assay (ELISA). RESULTS Three peptide biomarkers were identified for distinguishing CC patients from normal individuals, and distinguishing preoperative CC patients from postoperative CC patients. Of these 3 identified protein peptide regions, 2 peptide regions - TKT (Peak 2, 2435.63 m/z, 499-524) and FGA (Peak 4, 2761.79 m/z, 603-629) - were identified as upregulated markers, and peptide region of APOA1 (Peak 9, 2575.3 m/z, 245-260) was identified as a downregulated biomarker in preoperative CC patients compared with healthy women. CONCLUSIONS The present study provides a new method for identifying potential serum biomarkers for CC patients.

miR-30a-3p Targets MAD2L1 and Regulates Proliferation of Gastric Cancer Cells.

PURPOSE: This study was done to investigate the inhibition effects of miR-30a-3p on mitotic arrest deficient 2 like 1 (MAD2L1) expression and the proliferation of gastric cancer cells. PATIENTS AND METHODS: Cluster analysis and the TCGA database were used to screen the key genes highly expressed in gastric cancer. Based on the LinkedOmics website, the correlation between the miR-30a-3p and the cell cycle-related target gene MAD2L1 in gastric cancer was analyzed. The mRNA and protein expression levels were detected with the quantitative real-time PCR and Western blot analysis. The cell proliferation and cell cycle were also detected and analyzed. RESULTS: Bioinformatics analysis showed that MAD2L1 was highly expressed in tumor tissues compared with normal tissues. Compared with normal tissues, the miR-30a-3p was significantly decreased in the gastric cancer tissues. Moreover, MAD2L1 was significantly negatively correlated with the miR-30a-3p expression. Furthermore, over-expression of miR-30a-3p decreased the expression of MAD2L1 at the protein level, which inhibited the proliferation of AGS and BGC-823 gastric cancer cells. In addition, the cell cycles of AGS and BGC-823 cells were arrested at the G0/G1 phase. CONCLUSION: MAD2L1 is a pro-oncogene which is up-regulated in gastric cancer. The miR-30a-3p can down-regulate the MAD2L1 expression, inhibiting the proliferation of gastric cancer cells and affect the cell cycle.