A transcribed ultraconserved noncoding RNA, uc.285+, promotes colorectal cancer proliferation through dual targeting of CDC42 by directly binding mRNA and protein.

The transcribed ultraconserved region (T-UCR) belongs to a new type of lncRNAs that are conserved in homologous regions of the rat, mouse and human genomes. A lot of research has reported that differential expression of T-UCRs can influence the development of various cancers, revealing the ability of T-UCRs as new therapeutic targets or potential cancer biomarkers. Most studies on the molecular mechanisms of T-UCRs in cancer have focused on ceRNA regulatory networks and interactions with target proteins, but the present study reveals an innovative dual-targeted regulatory approach in which T-UCRs bind directly to mRNAs and directly to proteins. We screened T-UCRs that may be related to colorectal cancer (CRC) by performing a whole-genome T-UCR gene microarray and further studied the functional mechanism of T-UCR uc.285+ in the development of CRC. Modulation of uc.285+ affected the proliferation of CRC cell lines and influenced the expression of the CDC42 gene. We also found that uc.285+ promoted the proliferation of CRC cells by directly binding to CDC42 mRNA and enhancing its stability while directly binding to CDC42 protein and affecting its stability. In short, our research on the characteristics of cell proliferation found that uc.285+ has a biological function in promoting CRC proliferation. uc.285+ may have considerable potential as a new diagnostic biomarker for CRC.

Inhibition of HDAC6 promotes microvascular endothelial cells to phagocytize myelin debris and reduces inflammatory response to accelerate the repair of spinal cord injury.

AIMS: To identify an effective strategy for promoting microvascular endothelial cells (MECs) to phagocytize myelin debris and reduce secretion of inflammatory factors following spinal cord injury (SCI). METHODS: We established a coculture model of myelin debris and vascular-like structures. The efficiency with which MECs phagocytize myelin debris under different conditions was examined via ELISA, flow cytometry, and immunofluorescence. Tubastatin-A was used to interfere with the coculture model. The anti-inflammatory effects of Tubastatin-A were observed by HE staining, flow cytometry, immunofluorescence, and ELISA. RESULTS: MECs phagocytized myelin debris via IgM opsonization, and phagocytosis promoted the secretion of inflammatory factors, whereas IgG-opsonized myelin debris had no effect on inflammatory factors. Application of the HDAC6 inhibitor Tubastatin-A increased the IgG levels and decreased the IgM levels by regulating the proliferation and differentiation of B cells. Tubastatin-A exerted a regulatory effect on the HDAC6-mediated autophagy-lysosome pathway, promoting MECs to phagocytize myelin debris, reducing the secretion of inflammatory factors, and accelerating the repair of SCI. CONCLUSIONS: Inhibition of HDAC6 to regulate the immune-inflammatory response and promote MECs to phagocytize myelin debris may represent a novel strategy in the treatment of SCI.

Pembrolizumab for the treatment of progressive multifocal leukoencephalopathy in China.

The aim of this study is to analyze the clinical characteristics and outcomes of Chinese patients with progressive multifocal leukoencephalopathy (PML) who were treated with programmed cell death protein 1 (PD1) blockade therapies. We retrospectively analyzed patients who were admitted to our hospital between October 1, 2020, and October 1, 2022, diagnosed with PML and treated with PD1 blockade therapies. Four patients with PML who were treated with PD1 blockade therapies were identified. All patients were male, and their ages ranged from 19 to 54 years old. One patient (Case 2) exhibited mild pleocytosis, while three patients (Cases 2-4) had markedly reduced T lymphocyte cell counts prior to treatment. The time interval between symptom onset and treatment initiation ranged from six to 54 weeks. All patients received pembrolizumab treatment, with a total of two to four doses administered. Three patients who responded to pembrolizumab treatment showed clinical improvement starting around 8 weeks after the initiation of therapy. Although one patient did not show clinical improvement, they ultimately survived until the last follow-up. None of the patients in this study exhibited immune-related adverse events or immune reconstitution inflammatory syndrome. PD1 blockade appears to be a promising novel therapeutic option for PML; additional prospective studies are necessary to confirm its efficacy.

circELMOD3 increases and stabilizes TRIM13 by sponging miR-6864-5p and direct binding to inhibit HCC progression.

Many circular RNAs (circRNAs) have been identified to be associated with hepatocellular carcinoma (HCC) progression. We aim to explore the diagnostic potential, functions, and mechanism of circELMOD3 in HCC. Differentially expressed circRNAs in HCC and its paired adjacent tissues were identified by RNA sequencing. circELMOD3 was downregulated in HCC tissues and was related to clinicopathological characteristics of HCC patients. Additionally, plasma circELMOD3 was shown to be a highly sensitive and non-invasive biomarker to distinguish HCC from healthy controls. Functional assays showed that circELMOD3 inhibited proliferation and induced apoptosis of HCC cells both in vitro and in vivo. Mechanistically, RNA antisense purification (RAP) and luciferase reporter assays verified that circELMOD3 functioned as a sponge for miR-6864-5p leading to increased expression of its target gene TRIM13. Interestingly, RNA stability test demonstrated that circELMOD3 overexpression led to enhanced stability of its directly bound TRIM13 mRNA, which in turn co-activated the p53 signaling pathway.

Iron induces B cell pyroptosis through Tom20-Bax-caspase-gasdermin E signaling to promote inflammation post-spinal cord injury.

BACKGROUND: Immune inflammatory responses play an important role in spinal cord injury (SCI); however, the beneficial and detrimental effects remain controversial. Many studies have described the role of neutrophils, macrophages, and T lymphocytes in immune inflammatory responses after SCI, although little is known about the role of B lymphocytes, and immunosuppression can easily occur after SCI. METHODS: A mouse model of SCI was established, and HE staining and Nissl staining were performed to observe the pathological changes. The size and morphology of the spleen were examined, and the effects of SCI on spleen function and B cell levels were detected by flow cytometry and ELISA. To explore the specific mechanism of immunosuppression after SCI, B cells from the spleens of SCI model mice were isolated using magnetic beads and analyzed by 4D label-free quantitative proteomics. The level of inflammatory cytokines and iron ions were measured, and the expression of proteins related to the Tom20 pathway was quantified by western blotting. To clarify the relationship between iron ions and B cell pyroptosis after SCI, we used FeSO4 and CCCP, which induce oxidative stress to stimulate SCI, to interfere with B cell processes. siRNA transfection to knock down Tom20 (Tom20-KD) in B cells and human B lymphocytoma cell was used to verify the key role of Tom20. To further explore the effect of iron ions on SCI, we used deferoxamine (DFO) and iron dextran (ID) to interfere with SCI processes in mice. The level of iron ions in splenic B cells and the expression of proteins related to the Tom20-Bax-caspase-gasdermin E (GSDME) pathway were analyzed. RESULTS: SCI could damage spleen function and lead to a decrease in B cell levels; SCI upregulated the expression of Tom20 protein in the mitochondria of B cells; SCI could regulate the concentration of iron ions and activate the Tom20-Bax-caspase-GSDME pathway to induce B cell pyroptosis. Iron ions aggravated CCCP-induced B cell pyroptosis and human B lymphocytoma pyroptosis by activating the Tom20-Bax-caspase-GSDME pathway. DFO could reduce inflammation and promote repair after SCI by inhibiting Tom20-Bax-caspase-GSDME-induced B cell pyroptosis. CONCLUSIONS: Iron overload activates the Tom20-Bax-caspase-GSDME pathway after SCI, induces B cell pyroptosis, promotes inflammation, and aggravates the changes caused by SCI. This may represent a novel mechanism through which the immune inflammatory response is induced after SCI and may provide a new key target for the treatment of SCI.

Construction and optimization of a coculture system of mouse brain microvascular endothelial cells and myelin debris.

Microvascular endothelial cells are a newly discovered cell type involved in the phagocytosis of myelin debris, which play a key role in the repair of spinal cord injuries. Several methods for the preparation of myelin debris and parameters for constructing a coculture system of microvascular endothelial cells and myelin debris are available, but no systematic studies have yet been conducted, which hinders further exploration of the mechanisms of demyelinating disease repair. Herein, we aimed to develop a standardized method for this process. Myelin debris of different sizes was obtained from the brains of C57BL/6 mice by stripping the brains under aseptic conditions, multiple grinding, gradient centrifugation, etc. Transmission electron microscopy and nanoparticle size analysis were used to characterize myelin debris. Microvascular endothelial cells were cultured on a matrix gel, and myelin debris of different sizes (fluorescently labeled using CFSE) was placed in coculture after forming a vascular-like structure. Subsequently, myelin debris of different concentrations was cocultured in the vascular-like structure, and phagocytosis of myelin debris by microvascular endothelial cells was detected using immunofluorescence staining and flow cytometry. We found that myelin debris could be successfuly obtained from the mouse brain with secondary grinding and other steps and cocultured with microvascular endothelial cells at a concentration of 2 mg/mL, which promoted the phagocytosis of microvascular endothelial cells. In conclusion, we provide a reference for the protocol of a coculture system of microvascular endothelial cells and myelin debris.

Anti-metabotropic glutamate receptor 5 encephalitis: Five case reports and literature review.

OBJECTIVE: To describe the clinical and radiological characteristics of anti-metabotropic glutamate receptor 5 (mGluR5) encephalitis. METHODS: We reviewed the clinical data of five patients with anti-mGluR5 encephalitis, and performed a literature review. RESULTS: The five cases included a 52-year-old man who developed a biphasic course of anti-mGluR5 encephalitis after herpes simplex encephalitis, a 22-year-old woman who showed bilateral basal ganglia lesions on brain magnetic resonance imaging (MRI), and a 36-year-old man with mixed aphasia and generalized tonic-clonic seizures, a 51-year-old man presented with personality changes, hallucinations, delusions, sleeping disorders and a 58-year-old man with short-term memory deficits and absence seizures.. There are 16 reported cases of anti-mGluR5 encephalitis worldwide. Of all 21 patients, with a median onset age of 35 years old, the main neurological symptoms were cognitive impairment (85.7%, 18/21), psychiatric or behavior problems (76.2%, 16/21), seizures (57.1%, 12/21), sleeping disorders (52.4%, 11/21), different degrees of decreased consciousness (42.9%, 9/21), and movement disorders (23.8%, 5/21). Brain MRI was normal in 11 of 21 patients. Lesions of the limbic lobes were presented in 5 patients, while involvement of other extralimbic regions was also reported. Seven of 21 (33.3%) cases were combined with tumors. Elevated white blood cell counts or specific oligoclonal IgG bands in the cerebrospinal fluid were found in 18 of 21 patients, with marked improvements observed after immunotherapy. DISCUSSION: Patients with anti-mGluR5 encephalitis typically present with diffuse, rather than purely limbic, encephalitis. Anti-mGluR5 encephalitis can be triggered by herpes simplex encephalitis. The risk of a combined tumor may be reduced in anti-mGluR5 encephalitis patients.

The pivotal regulatory factor circBRWD1 inhibits arsenic exposure-induced lung cancer occurrence by binding mRNA and regulating its stability.

Multiple studies have indicated that circular RNAs (circRNAs) play a regulatory role in different stages of tumors by interacting with various molecules. With continuous in-depth research on the biological functions of circRNAs, increasing evidence has shown that circRNAs play important roles in carcinogenesis caused by environmental pollutants. However, the function and mechanism of circRNAs in arsenic exposure-induced lung cancer occurrence have not been reported. In this study, RNA sequencing and qPCR assays revealed that the expression of circBRWD1 was decreased in BEAS-2B-As cells and multiple lung cancer cell lines. Silencing circBRWD1 promoted cell viability and proliferation, inhibited cell apoptosis, and accelerated the G0/G1 phase transition in BEAS-2B-As cells; however, these functions were abrogated by circBRWD1 overexpression. Mechanistically, under arsenic exposure, expression of decreased circBRWD1 led to enhanced stability of the mRNA to which it directly binds (c-JUN, c-MYC, and CDK6 mRNA), increasing its expression. This mechanism promotes the malignant transformation of lung cells and ultimately leads to lung cancer. Our findings thus reveal the molecular mechanism of arsenic carcinogenesis.

Circular RNA circLAMA3 inhibits the proliferation of bladder cancer by directly binding an mRNA.

The circular RNA (circRNA) circLAMA3 is significantly downregulated in bladder cancer tissues and cell lines. However, its function in bladder cancer has not yet been explored, and further research is needed. In this study, functional experiments demonstrated that circLAMA3 significantly inhibited the proliferation, migration, and invasion of bladder cancer cells and inhibited bladder cancer growth in vivo. Mechanistically, circLAMA3 directly binds to and promotes the degradation of MYCN mRNA, thereby reducing the MYCN protein expression in bladder cancer cells. Decreased expression of the MYCN protein inhibits the promoter activity and expression of CDK6. Ultimately, circLAMA3 affects DNA replication by downregulating CDK6, resulting in G0/G1 phase arrest and inhibition of bladder cancer proliferation. In summary, we report a potential novel regulatory mechanism via which a circRNA directly binds an mRNA and thereby regulates its fate. Moreover, circLAMA3 significantly affects the progression of bladder cancer and has potential as a diagnostic biomarker and therapeutic target for bladder cancer.

Investigating the genomic alteration improved the clinical outcome of aged patients with lung carcinoma.

BACKGROUND: Lung carcinoma is a common geriatric disease. The development of genotype-targeted therapies greatly improved the management of lung carcinoma. However, the treatment for old patients can be more complex than that for young individuals. RESULTS: To investigate the benefits of genetic detection for older patients with lung carcinoma, we explored the genomic profiling of 258 patients with more than 55 years using a targeted next generation sequencing, and some of these patients were treated with targeted therapies based on the results of genomic detection. KRAS codon 61 mutations were found in 15.2% KRAS-mutated patients, which tend to be co-existing with other classical activating mutations other than codons 12/13. Acquired EGFR C797S mutations were identified in 2 cases and ERBB2 amplification was identified in 1 case. All these 3 cases developed resistance to EGFR tyrosine kinase inhibitors and showed expected results of their followed therapies. The median progression-free survival and median overall survival of patients treated with molecular targeted therapies were better than those of patients treated with chemoradiotherapy alone. CONCLUSIONS: Our findings revealed the specific genomic profiles of patients older than 55 years with lung carcinoma and suggested that these old patients have been benefit from the genetic detection, which helped identify druggable mutations and distinguish resistance mechanisms.

Circular RNA circGLIS3 promotes bladder cancer proliferation via the miR-1273f/SKP1/Cyclin D1 axis.

Extensive research confirmed that circRNA can play a regulatory role in various stages of tumors by interacting with various molecules. Identifying the differentially expressed circRNA in bladder cancer and exploring its regulatory mechanism on bladder cancer progression are urgent. In this study, we screened out a circRNA-circGLIS3 with a significant upregulation trend in both bladder cancer tissues and cells. Bioinformatics prediction results showed that circGLIS3 may be involved in multiple tumor-related pathways. Function gain and loss experiments verified circGLIS3 can affect the proliferation, migration, and invasion of bladder cancer cells in vitro. Moreover, silencing circGLIS3 inhibited bladder cancer cell growth in vivo. Subsequent research results indicated circGLIS3 regulated the expression of cyclin D1, a cell cycle-related protein, and cell cycle progression. Mechanically, circGLIS3 upregulates the expression of SKP1 by adsorbing miR-1273f and then promotes cyclin D1 expression, ultimately promoting the proliferation of bladder cancer cells. In summary, our study indicates that circGLIS3 plays an oncogene role in the development of bladder cancer and has potential to be a candidate for bladder cancer.

Combination therapy with afatinib and bevacizumab in an EGFR-mutated non-small cell lung cancer patient with acquired ERBB2 amplification: A case report.

INTRODUCTION: Acquired resistance to reversible EGFR tyrosine kinase inhibitors remains a significant obstacle, and acquired ERBB2 amplification is the most common "bypass" mechanism. For patients with sensitizing EGFR mutation who experience resistance via ERBB2 amplification, no targeted drug has been demonstrated to be effective. PATIENT CONCERNS: A 56-year-old female nonsmoker suffered from left leg paralysis and low back pain. Imaging examination revealed a mass in the anterior segment of the right upper lobe lung and possible multiple metastases in the right hilar, mediastinal lymph nodes, bone metastases, and soft tissue invasion. DIAGNOSIS: Transbronchial lung biopsy revealed a moderately differentiated adenocarcinoma (cT4N2M1c, stage IV). An EGFR exon 19 deletion was identified using amplification refractory mutation system. INTERVENTIONS: After the patient was treated with gefitinib initiation (250 mg/d) for 15 months, the tumor progressed with ERBB2 amplification revealed by next-generation sequencing test. Then, the patient was started on afatinib (40 mg/d) plus bevacizumab (7.5 mg/kg every 3 weeks). OUTCOMES: The combination therapy of afatinib and bevacizumab in this patient was effective with some slight side effects. Computed tomography scans showed the tumor shrinkage and the pleural effusion disappeared in the right lung. The overall survival was 23.5 months. CONCLUSION: To date, there is no targeted therapy approved and demonstrated to be effective for non-small cell lung cancer patients with EGFR sensitizing mutations, and ERBB2 amplification. The effectiveness of combination therapy with afatinib and bevacizumab may provide a new therapeutic option for these patients.

CYP2S1 might regulate proliferation and immune response of keratinocyte in psoriasis.

Psoriasis is an autoimmune skin disorder influenced by genetic, epigenetic and environmental factors. We previously found CYP2S1 intragenic DNA methylation cg19430423 site strongly hypomethylated in psoriatic skin tissues. In this study, we performed methylation loci fine-mapping to search the top signals in the entire CYP2S1 gene region, and further carried out gene expression assay, cell proliferation, apoptosis, differentiation and migration in CYP2S1 overexpressed (CYP2S1over) and silenced (siRNA) human keratinocytes. Target bisulphite conversion sequencing revealed cg19430423 and nearby two loci were the top differentially methylated loci. These three loci located within active enhancer region marked by H3K4Me1 and H3K27AC peaks. Cg19430423 might not bind with ATF1 directly. CYP2S1over repressed NHEK cell proliferation, but have no confirmed evidence on affecting migration, apoptosis and differentiation. Real-time PCR showed that CYP2S1 inhibited expression of IL1ß, IL8, IL33, IL36, LL37, CXCL10 and CCL20 gene. In summary, CYP2S1 might inhibit keratinocyte proliferation, and modulate immune response through IL-8, IL-33, IL-36, CXCL-10, CCL20, thus contribute to the development of psoriasis.