Solid tumors have the unique extracellular matrix that can largely regulate the malignant behavior of tumor cells， including immune escape. The majority of solid tumors can form tumor fibrosis， which is mainly conferred by collagen in the extracellular matrix. Collagen is one of the most abundant proteins in the human body and mainly produced by tumor-associated fibroblasts in tumor tissues， which plays a critical role in tumor immune escape by inhibiting a variety of tumorinfiltrating immune cells. Collagen can be used both as a biomarker for prognosis in cancer patients and as an effective target for cancer therapy. This review summarized the roles of tumor fibrosis in tumors， especially the effect on tumor-infiltrating immune cells， and focused on the research methods of tumor fibrosis and treatment-related research progress. In addition， this review introduces the interpretation of "immuno-collagenic subtypes" based on collagen deposition and immune activity and the concept of "armored & cold tumors" proposed by our research group.
This study aims to investigate the role of E1A binding protein p300（EP300） in bladder tumor progression and its underlying molecular mechanisms， with the goal of providing new insights for bladder cancer therapeutic strategies.
Methods
EP300 was knocked down in UMUC3 bladder tumor cells， followed by assessments of cell proliferation， migration， and invasion using CCK-8， wound healing， and Transwell assays. Transcriptome sequencing and data analysis were conducted to identify downstream effector molecules. The regulation of these molecules by EP300 was validated using RT-qPCR， Western blot， and ChIP-qPCR assays. Comparisons between two groups were conducted using the t-test. For comparisons among three or more groups，one-way ANOVA was employed， followed by Dunnett's t-test for post hoc pairwise comparisons.
Results
Compared with the control group， knockdown of EP300 significantly inhibited the proliferation ［（1.49 ± 0.05） vs （1.16 ± 0.06） ， （1.07 ± 0.04） ， P＜ 0.05］， migration ［（100.32 ±5.16） vs （52.16 ± 2.07）， （43.19 ± 7.64）， P＜ 0.05］， and invasion ［（99.52 ± 3.84） vs （33.07 ±7.14）， （64.22 ± 4.15）， P＜ 0.05］ of UMUC3 cells （P＜ 0.05）. Transcriptome sequencing revealed that FK506 binding protein 10 （FKBP10） was significantly downregulated upon EP300 knockdown［（1.02 ± 0.11） vs （0.18 ± 0.04）， P＜ 0.05］. The expression level of FKBP10 also decreased ［（0.99 ±0.07） vs （0.44 ± 0.09）， P＜ 0.05］ after treatment with C646， an inhibitor of EP300's acetyltransferase activity. ChIP- qPCR results confirmed that EP300 promotes the transcriptional activity of FKBP10 by enhancing H3K27 acetylation in the promoter region of FKBP10 ［（1.40 ± 0.05） vs （0.54 ± 0.01），P＜ 0.05］.
Conclusion
This study revealed that EP300 promotes bladder tumor progression by upregulating FKBP10 expression.
To analyze the expression of Optic Atrophy 1 （OPA1） in breast cancer and its effect on the biological function of estrogen receptor （ER）-positive breast cancer cells， seeking potential new targets for breast cancer therapy.
Methods
Expression differences of OPA1 in breast cancer and normal/paracancerous tissues were analyzed using publicly available database information （HPA and GSE115144） and tissue microarrays from ER-positive breast cancer patients， respectively. The correlation between OPA1 expression and survival in breast cancer patients was analyzed by the GEPIA and TCGA databases. In cellexperiments， MCF7 and T47D cells were transfected with OPA1 plasmid and small interfering RNA （siRNA）， respectively， and the relative expression levels of mRNA and protein of OPA1 were detected by RT-qPCR and Western blot. Cell proliferation and clone formation ability were detected by CCK-8 assay and plate clone formation assay， respectively. Reactive oxygen species （ROS） level， mitochondrial membrane potential （JC- 1 method） and apoptosis rate were detected by flow cytometry. Two independent samples t-test was used for comparison between groups. Differences among groups were compared by one-way ANOVE analysis， and Dunnett-t test was used for pair-to-group comparisons.
Results
OPA1 was highly expressed in breast cancer tissues compared with paracancerous tissues （P＜ 0.01）， and high OPA1 expression was associated with poor clinical prognosis in breast cancer patients （P＜ 0.05）. In cell experiments， overexpression of OPA1 promoted cell proliferation and clone formation and decreased the ROS levels ［（37.37 ± 1.48）% vs （62.51 ± 2.66）%， P＜ 0.001］， along with an increase in mitochondrial membrane potential ［decrease in the proportion of JC-1 monomers， （7.32 ± 1.84）% vs（17.6 ± 3.35）%， P＜ 0.01］； while inhibition of OPA1 was able to inhibit cell proliferation and clone formation， increase ROS levels ［（77.81 ± 2.37）% vs （58.37 ± 1.36）%， P＜ 0.001］， decreasing mitochondrial membrane potential ［elevated proportion of JC-1 monomer， （28.13 ± 3.47）% vs（15.96 ± 1.14）%， P＜ 0.01］， and promote apoptosis ［（20.10 ± 1.20）% vs （3.85 ± 0.76）%， P＜0.001］.
Conclusion
OPA1 is highly expressed in breast cancer and is significantly associated with poor clinical prognosis. Inhibition of OPA1 expression inhibits the cell proliferation and clone formation of ER-positive breast cancer， while decreasing mitochondrial membrane potential， affecting mitochondrial function，inducing ROS generation andultimately promote cell apoptosis.
To evaluate the effects of transjugular intrahepatic portosystemic shunt （TIPS） on gut microbiota， mucosal barrier， and liver function in patients with cirrhotic portal hypertension and esophagogastric variceal bleeding （EGVB）.
Methods
A prospective cohort study was conducted on patients with cirrhotic portal hypertension and EGVB scheduled for TIPS.Age-and sex-matched healthy volunteers were set as the control group. Blood and stool samples were collected pre-procedure， and at 1 and 12 weeks post-TIPS. The control group provided samples once. Gut microbiota was analyzed using 16SrRNA sequencing. Plasma lipopolysaccharide （LPS），diamine oxidase （DAO）， and D-lactate （DLAC） levels were assessed via ELISA. Liver function was evaluated using an automated biochemical analyzer. Dynamic changes and differences in these indicators pre- and post-treatment were compared between groups.
Results
Portal vein pressure was significantly decreased post-TIPS compared to pre-TIPS （P＜ 0.001）. Patients with cirrhotic portal hypertension showed significantly lower gut microbiota richness and diversity than the healthy controls， with a reduction in beneficial bacteria and an increase in potential pathogens. However，at 12 weeks post-TIPS， gut microbiota richness and diversity were significantly improved， with an increase in beneficial bacteria and a marked reduction in potential pathogens. The plasma DLAC level was significantly elevated in patients with cirrhotic portal hypertension， with statistically significant differences compared to the control group at all time points. Compared to the patient group at 12 weeks post-TIPS， DAO levels were elevated both pre-TIPS and at 1 week post-TIPS. Compared to pre-TIPS levels， LPS levels were higher at 1 week post-TIPS ［（0.69 ± 0.14） vs （0.60 ± 0.21） pg/ mL］，while LPS levels decreased at 12 weeks post-TIPS［（0.55 ± 0.12） vs （0.60 ± 0.21） pg/ mL］， with statistically significant differences （all P＜ 0.05 ）.
Conclusion
Patients with cirrhotic portal hypertension exhibit dysbiosis and impaired intestinal mucosal barriers. TIPS reduces portal vein pressure and can improve gut microbiota in the long term.
To investigate the effect of collagen/DDR2 signaling on the proliferation and migration of renal fibroblasts during renal interstitial fibrosis.
Methods
A renal tubulointerstitial fibrosis model was established in SPF male C57BL/6 mice via unilateral ureteral obstruction （UUO）， and pathological samples and fresh tissues were obtained for Western blotting and immunohistochemistry. Human kidney fibroblasts were cultivated， followed by the transfection of KFB cells with shDDR2 and its negative control lentivirus， OE-DDR2 and its negative control lentivirus， and screening with 5 μg/mL puromycin. A stable transfection cell line was then created and exposed to 10 μg/mL collagen for 48 hours. Control Group 1： shCtrl + Collagen group （shDDR2 negative control， without downregulation of DDR2 expression but with collagen treatment）； Control Group 2： Control + Collagen group （OE-DDR2 negative control， without overexpression of DDR2 but with collagen treatment）； Experimental Group 1： shDDR2 + Collagen group （DDR2 gene knockdown with collagen treatment）； Experimental Group 2： OE-DDR2 + Collagen group （DDR2 gene overexpression with collagen treatment）； Experimental Group 3： Based on Experimental Group 2， treated with 1 μmol/L dasatinib， with all groups being treated for 48 hours. The expression level of DDR2 mRNA was detected by RT-qPCR， and the level of DDR2 protein was assessed by Western blot. Cell proliferation was evaluated using the CCK-8 assay and the BrdU assay. Cell localization and pathological changes were observed by HE staining and immunohistochemical staining methods. Comparisons between two groups were performed using independent samples t-test， and the t' test was used when variances were unequal. For comparisons among multiple groups，one-way ANOVA was applied， with LSD-t test used for pairwise comparisons when variances were homogeneous， and Tamhane's T2 test was used when variances were heterogeneous.
Results
DDR2 is localized in renal stromal fibroblasts in mouse kidney tissue， and has a colocalization relationship with collagen. Compared with the shCtrl+collagen group， the cell proliferation rate （0.28 ± 0.00 vs 0.38 ± 0.01） in the sh-DDR2+ collagen group slowed down （P＜ 0.05）， and the transwell transfer rate （6.00 ± 1.00 vs 21.66 ± 0.57） decreased （P＜ 0.05）. Compared with the Control+collagen group， the cell proliferation rate of the OE-DDR2+ collagen group （0.43 ± 0.01 vs 0.39 ± 0.01） was accelerated （P＜ 0.05）， and the transwell mobility rate （32.66 ± 0.57 vs 22.33 ± 0.57） was increased（P＜ 0.05）. After the addition of dasatinib， the cell proliferation rate （0.36 ± 0.00 vs 0.39 ± 0.01）was significantly reduced.
Conclusion
Collagen/DDR2 signaling activation significantly promoted the proliferation of KFB cells and inhibited apoptosis， ultimately promoting the occurrence and development of renal interstitial fibrosis.
To further explore the pathogenesis of Stanford Type A aortic dissection and screen potential novel molecular biomarkers by identifying differentially expressed genes in Stanford Type A aortic dissection and constructing a gene co-expression network.
Methods
Gene expression arrays of Stanford Type A aortic dissection were obtained from the GEO database. The R limma package was used to screen differentially expressed mRNAs（ P＜ 0.05，|log2FC|＞ 1）. Key differentially expressed genes involved in the pathogenesis of aortic dissection were selected for comprehensive investigation. Subsequently， the expression of key differentially expressed genes and the coded protein were validated by quantitative real-time PCR and Western blot in vascular wall tissues from Stanford Type A aortic dissection patients and control group. The gene co-expression network of the selected gene was constructed by bioinformatic analysis； To clarify the biological functions of the co-expression network， the function and pathway enrichment analysis of the co-expressed genes were performed by ggplot2 package in R language. Further， a protein- protein interaction （PPI） network of these co-expressed genes was constructed to identify the genes interacting with the hub gene directly and validate their correlation. By integrating gene co-expression and PPI networks， we established the gene interaction mechanisms relevant to aortic dissection and explored the specific molecular mechanisms underlying its pathogenesis. Independent sample t test was used for comparison between the two groups.
Results
A total of 969 differentially expressed genes were identified in Stanford Type A aortic dissection through the application of the WALD test. Based on co-expression network analysis， we selected the upregulated gene KIF20A for further investigation in aortic dissection， and subsequently validated its elevated expression levels in clinical samples. There were 53 genes in the co-expression network of KIF20A， with 20 genes positively correlated and 33 negatively correlated with KIF20A expression. Functional enrichment analysis of this network was mainly enriched in biological processes such as polarity regulation of epithelial cells，mitochondrial function， and arginine and proline metabolism. Further analysis showed that CDK1 directly interacted with KIF20A， and the expression levels of the two genes were positively correlated（r = 0.83，P＜ 0.001）.
Conclusion
KIF20A is significantly elevated in Stanford Type A aortic dissection tissues and potentially interacts with CDK1， regulating the expression of a series of genes affecting biological processes such as polarity establishment and regulation of epithelium and tissue，mitochondrial function， and thus mediating the occurrence and development of aortic dissection.
The gut-brain axis is the bidirectional regulation between the gastrointestinal tract and the central nervous system. In recent years， the gut-brain axis has become a new research hotspot，and many studies have explored the relationship between gut microbiota and nervous system diseases.Stem cell therapy is a regenerative medicine treatment method. Mesenchymal stem cells （MSCs） have shown good efficacy in improving neuropathological injury and intestinal inflammation. The current article describes the relationship between the gut-brain axis and several common nervous system diseases and the key role of the gut-brain axis in disease progression， pointing out the advantages and potential of mesenchymal stem cells in regulating gut-brain axis in the treatment of nervous system diseases， and reviews the application progress of mesenchymal stem cells in regulating the gut-brain axis in the treatment of nervous system diseases， providing new ideas for the treatment of nervous system diseases.
