A specific super-enhancer actuated by berberine regulates EGFR-mediated RAS-RAF1-MEK1/2-ERK1/2 pathway to induce nasopharyngeal carcinoma autophagy.

Nasopharyngeal carcinoma (NPC), primarily found in the southern region of China, is a malignant tumor known for its highly metastatic characteristics. The high mortality rates caused by the distant metastasis and disease recurrence remain unsolved clinical problems. In clinic, the berberine (BBR) compound has widely been in NPC therapy to decrease metastasis and disease recurrence, and BBR was documented as a main component with multiple anti-NPC effects. However, the mechanism by which BBR inhibits the growth and metastasis of nasopharyngeal carcinoma remains elusive. Herein, we show that BBR effectively inhibits the growth, metastasis, and invasion of NPC via inducing a specific super enhancer (SE). From a mechanistic perspective, the RNA sequencing (RNA-seq) results suggest that the RAS-RAF1-MEK1/2-ERK1/2 signaling pathway, activated by the epidermal growth factor receptor (EGFR), plays a significant role in BBR-induced autophagy in NPC. Blockading of autophagy markedly attenuated the effect of BBR-mediated NPC cell growth and metastasis inhibition. Notably, BBR increased the expression of EGFR by transcription, and knockout of EGFR significantly inhibited BBR-induced microtubule associated protein 1 light chain 3 (LC3)-II increase and p62 inhibition, proposing that EGFR plays a pivotal role in BBR-induced autophagy in NPC. Chromatin immunoprecipitation sequencing (ChIP-seq) results found that a specific SE existed only in NPC cells treated with BBR. This SE knockdown markedly repressed the expression of EGFR and phosphorylated EGFR (EGFR-p) and reversed the inhibition of BBR on NPC proliferation, metastasis, and invasion. Furthermore, BBR-specific SE may trigger autophagy by enhancing EGFR gene transcription, thereby upregulating the RAS-RAF1-MEK1/2-ERK1/2 signaling pathway. In addition, in vivo BBR effectively inhibited NPC cells growth and metastasis, following an increase LC3 and EGFR and a decrease p62. Collectively, this study identifies a novel BBR-special SE and established a new epigenetic paradigm, by which BBR regulates autophagy, inhibits proliferation, metastasis, and invasion. It provides a rationale for BBR application as the treatment regime in NPC therapy in future.

Berberine-mediated Ferroptosis through System Xc-/GSH/GPX4 Axis Inhibits Metastasis of Nasopharyngeal Carcinoma.

Nasopharyngeal carcinoma (NPC) is a malignant tumor that is highly prevalent in Southeast China, and its metastasis remains an unresolved clinical problem. Ferroptosis, a type of nonapoptotic cell death, is a critical pathway in tumor metastasis. Berberine (BBR), a plant alkaloid, has been explored as a potential anti-NPC metastatic agent; however, the underlying mechanisms are unknown. Here, we showed that BBR exerted its anti-metastasis role by inhibiting system Xc-/GSH/GPX4 axis-driven ferroptosis. The present study demonstrated for the first time that BBR induced ferroptosis in NPC cells by increasing reactive oxygen species, lipid peroxidation and cellular Fe2+ and that the ferroptosis inhibitors Ferrostatin-1 and Deferoxamine mesylate rescued BBR-induced NPC cell death. Moreover, the ferroptotic characteristics of BBR-treated NPC cells were observed using transmission electron microscopy. Mechanistically, system Xc- (SLC7A11 and SLC3A2) and GSH levels were found to be suppressed after treatment with BBR. We demonstrated that the system Xc-/GSH/GPX4 axis was a critical mediator of BBR-induced ferroptosis. Furthermore, GPX4, a key inhibitor of lipid peroxidation, was greatly suppressed by BBR at both protein and mRNA levels. Molecular docking results showed a strong interaction between GPX4 and BBR. Notably, GPX4 overexpression reversed the effect of BBR-induced ferroptosis in NPC cells. Finally, BBR-mediated inhibition of NPC metastasis was validated in vivo using a mouse model. Taken together, our data suggest that BBR induced ferroptosis of NPC cells via suppressing the system Xc-/GSH/GPX4 axis, provides new insights into the mechanism of BBR anti-NPC metastasis.

Carcinogen-induced super-enhancer RNA promotes nasopharyngeal carcinoma metastasis through NPM1/c-Myc/NDRG1 axis.

Chemical carcinogen is one etiology of nasopharyngeal carcinoma (NPC) occurrence, N,N'-Dinitrosopiperazine (DNP) has been verified to cause NPC cell metastasis and generate induced pluripotent stem cells (iPSCs). To investigate the oncogenic mechanism of DNP, NPC cells were exposed to DNP, and subjected to RNA-seq, GRO-seq, ChIP-seq, and data analysis. The results showed that the super-enhancer RNA (seRNA) participates in DNP-mediated NPC metastasis through regulating N-myc downstream regulated gene 1 (NDRG1). Mechanistically, DNP exposure upregulates the levels of NPC metastatic seRNA (seRNA-NPCm), seRNA-NPCm interacted with a special super-enhancer (SE) upstream of NDRG1 gene and bound to nucleophosmin (NPM1)/c-Myc complex at the NDRG1 promoter, resulting in an increase of NDRG1 transcription. Functional studies showed that DNP significantly increased the metastatic capability of NPC cells in vitro and in vivo. Knockdown of seRNA-NPCm in NPC cells impaired the capability of metastasis. Furthermore, stably overexpressing seRNA-NPCm significantly increased the metastatic ability of NPC cells, while restoration of NDRG1 levels in these cells restored their metastatic capacity. Finally, the immunohistochemistry and in situ hybridization analyses revealed that the expression of seRNA-NPCm in NPC patients is positively correlated with NDRG1, and the NDRG1 level independently predicts poor prognosis of NPC patients. Collectively, DNP induces seRNA-NPCm, and seRNA-NPCm promotes NPC metastasis through NPM1/c-Myc/NDRG1 axis.

JUN-induced super-enhancer RNA forms R-loop to promote nasopharyngeal carcinoma metastasis.

Oncogenic super-enhancers (SEs) generate noncoding enhancer/SE RNAs (eRNAs/seRNAs) that exert a critical function in malignancy through powerful regulation of target gene expression. Herein, we show that a JUN-mediated seRNA can form R-loop to regulate target genes to promote metastasis of nasopharyngeal carcinoma (NPC). A combination of global run-on sequencing, chromatin-immunoprecipitation sequencing, and RNA sequencing was used to screen seRNAs. A specific seRNA associated with NPC metastasis (seRNA-NPCM) was identified as a transcriptional regulator for N-myc downstream-regulated gene 1 (NDRG1). JUN was found to regulate seRNA-NPCM through motif binding. seRNA-NPCM was elevated in NPC cancer tissues and highly metastatic cell lines, and promoted the metastasis of NPC cells in vitro and in vivo. Mechanistically, the 3' end of seRNA-NPCM hybridizes with the SE region to form an R-loop, and the middle segment of seRNA-NPCM binds to heterogeneous nuclear ribonucleoprotein R (hnRNPR) at the promoter of distal gene NDRG1 and neighboring gene tribbles pseudokinase 1 (TRIB1). These structures promote chromatin looping and long-distance chromatin interactions between SEs and promoters, thus facilitating NDRG1 and TRIB1 transcription. Furthermore, the clinical analyses showed that seRNA-NPCM and NDRG1 were independent prognostic factors for NPC patients. seRNA-NPCM plays a critical role in orchestrating target gene transcription to promote NPC metastasis.

Clinical performance of metagenomic next-generation sequencing for the rapid diagnosis of talaromycosis in HIV-infected patients.

Background: Talaromycosis is an invasive endemic mycosis caused by the dimorphic fungus Talaromyces marneffei (T. marneffei, TM). It mainly affects immunodeficient patients, especially HIV-infected individuals, which causes significant morbidity and mortality. Culture-based diagnosis takes a long turnaround time with low sensitivity, leading to treatment delay. In this study, we aimed to evaluate the performance of Metagenomic Next-Generation Sequencing (mNGS) for the rapid diagnosis of talaromycosis in HIV-infected patients. Methods: Retrospectively analysis was conducted in HIV-infected cases at Changsha First Hospital (China) from January 2021 to March 2022. Patients who underwent routine microbiological examination and mNGS testing in parallel were enrolled. The clinical final diagnosis was used as a reference standard, and cases were classified into the TM group (60 cases) and the non-TM group (148 cases). The clinical performances of mNGS were compared with culture and serum Galactomannan (GM). The mixed infections detected by mNGS were analyzed. The impact of mNGS detection on treatment was also investigated. Results: The sensitivity of mNGS test reached 98.3% (95% CI, 89.8-99.9), which was significantly higher than culture (66.7% [95% CI, 53.2-77.9], P < 0.001) and serum GM (83.3% [95% CI, 71.0-91.2], P < 0.05). The specificity of 98.6% (95% CI, 94.7-99.7) was similar to culture (100.0% [95% CI, 96.8-100.0], P = 0.156), and superior to serum GM (91.9% [95% CI, 85.9-95.5], P < 0.05). In bronchoalveolar lavage fluid (BALF) samples, the positive rate of mNGS was 97.6%, which was significantly higher than culture (28.6%, P <0.001). mNGS has excellent performance in the identification of mixed infection in TM group patients. Cytomegalovirus, Epstein-Barr virus and Pneumocystis jirovecii were the most common concurrent pathogens. In summary, 60.0% (36/60) patients were added or adjusted to antimicrobial therapy after mNGS test. Conclusion: mNGS is a powerful technique with high specificity and sensitivity for the rapid diagnosis of talaromycosis. mNGS of BALF samples may be a good option for early identification of T. marneffei in HIV-infected individuals with manifestations of infection. Moreover, mNGS shows excellent performance in mixed infection, which benefits timely treatment and potential mortality reduction.

Transcriptional factor III A promotes colorectal cancer progression by upregulating cystatin A.

BACKGROUND: Advanced colorectal cancer (CRC) generally has poor outcomes and high mortality rates. Clarifying the molecular mechanisms underlying CRC progression is necessary to develop new diagnostic and therapeutic strategies to improve CRC outcome and decrease mortality. Transcriptional factor III A (GTF3A), an RNA polymerase III transcriptional factor, is a critical driver of tumorgenesis and aggravates CRC cell growth. AIM: To confirm whether GTF3A promotes CRC progression by regulating the expression of cystatin A (Csta) gene and investigate whether GTF3A can serve as a prognostic biomarker and therapeutic target for patients with CRC. METHODS: Human tissue microarrays containing 90 pairs of CRC tissues and adjacent non-tumor tissues, and human tissue microarrays containing 20 pairs of CRC tissues, adjacent non-tumor tissues, and metastatic tissues were examined for GTF3A expression using immunohistochemistry. The survival rates of patients were analyzed. Short hairpin GTF3As and CSTAs were designed and packaged into the virus to block the expression of Gtf3a and Csta genes, respectively. In vivo tumor growth assays were performed to confirm whether GTF3A promotes CRC cell proliferation in vivo. Electrophoretic mobility shift assay and fluorescence in situ hybridization assay were used to detect the interaction of GTF3A with Csta, whereas luciferase activity assay was used to evaluate the expression of the Gtf3a and Csta genes. RNA-Sequencing (RNA-Seq) and data analyses were used to screen for target genes of GTF3A. RESULTS: The expression of GTF3A was higher in CRC tissues and lymph node metastatic tissues than in the adjacent normal tissues. GTF3A was associated with CRC prognosis, and knockdown of the Gtf3a gene impaired CRC cell proliferation, invasion, and motility in vitro and in vivo. Moreover, RNA-Seq analysis revealed that GTF3A might upregulate the expression of Csta, whereas the luciferase activity assay showed that GTF3A bound to the promoter of Csta gene and increased Csta transcription. Furthermore, CSTA regulated the expression of epithelial-mesenchymal transition (EMT) markers. CONCLUSION: GTF3A increases CSTA expression by binding to the Csta promoter, and increased CSTA level promotes CRC progression by regulating the EMT. Inhibition of GTF3A prevents CRC progression. Therefore, GTF3A is a potential novel therapeutic target and biomarker for CRC.

A novel oncogenic seRNA promotes nasopharyngeal carcinoma metastasis.

Nasopharyngeal carcinoma (NPC) is a common malignant cancer in southern China that has highly invasive and metastatic features and causes high mortality, but the underlying mechanisms of this malignancy remain unclear. In this study, we utilized ChIP-Seq to identify metastasis-specific super enhancers (SEs) and found that the SE of LOC100506178 existed only in metastatic NPC cells and powerfully aggravated NPC metastasis. This metastatic SE transcribed into lncRNA LOC100506178, and it was verified as a seRNA through GRO-Seq. Furthermore, SE-derived seRNA LOC100506178 was found to be highly expressed in metastatic NPC cells and NPC lymph node metastatic tissues. Knockdown of seRNA LOC100506178 arrested the invasion and metastasis of NPC cells in vitro and in vivo, demonstrating that seRNA LOC100506178 accelerates the acquisition of NPC malignant phenotype. Mechanistic studies revealed that seRNA LOC100506178 specifically interacted with the transcription factor hnRNPK and modulated the expression of hnRNPK. Further, hnRNPK in combination with the promoter region of MICAL2 increased Mical2 transcription. Knockdown of seRNA LOC100506178 or hnRNPK markedly repressed MICAL2, Vimentin and Snail expression and upregulated E-cadherin expression. Overexpression of seRNA LOC100506178 or hnRNPK markedly increased MICAL2, Vimentin and Snail expression and decreased E-cadherin expression. Therefore, seRNA LOC100506178 may promote MICAL2 expression by upregulating hnRNPK, subsequently enhancing EMT process and accelerating the invasion and metastasis of NPC cells. seRNA LOC100506178 has the potential to serve as a novel prognostic biomarker and therapeutic target in NPC patients.

Oncogenic super-enhancer formation in tumorigenesis and its molecular mechanisms.

Super-enhancers (SEs) consist of a cluster of many enhancers bound to a great number of transcription factors. They are critical cis-regulatory elements that determine the identity of various human cell types. During tumorigenesis, DNA mutations and indels, chromosomal rearrangements, three-dimensional chromatin structural changes, and viral infections mediate oncogenic SE activation, and activated SEs have been found to regulate the expression of oncogenic genes. Inhibition specifically targeted to oncogenic SE assembly and activation provides a novel powerful therapeutic strategy for various cancers. In this paper, we first introduce the current understanding of oncogenic SE assembly and activation and then summarize the pathogenic factors and mechanism of oncogenic SE activation. Next, we elaborate on the oncogenic functions of SEs in cancers and the application of SEs as therapeutic targets. Finally, we turn our focus to the use of SEs in basic research and clinical trials.

Antitumor activity of recombinant RGD-IFN-α2a-core fusion protein in vitro.

Interferon (IFN) regulates immune responses and antitumor activity. Arginine-glycine-aspartic acid (RGD) peptides can specifically bind to integrin αvß3, a transmembrane receptor that is highly expressed on the surface of various cancer cells. In this study, we expressed recombinant RGD-IFN-α2a-core fusion proteins and assessed their antitumor activity in vitro. Two RGD-IFN-α2a-core fusion proteins and a negative control protein were expressed in vitro. These two RGD-IFN-α2a-core fusion proteins could bind the tumor cell surface specifically and did not bind to normal cells. RGD-IFN-α2a-core fusion protein treatment of tumor cells significantly reduced cell viability and induced apoptosis in a dose-dependent manner. At the 'mRNA' level, both proteins could upregulate CASP3 expression. These data indicate that both laboratory-engineered RGD-IFN-α2a-core fusion proteins could bind the surface of tumor cells and induce apoptosis in vitro. Further studies will investigate the in-vivo antitumor activities of the RGD-IFN-α2a-core fusion proteins.

Self-assembled HCV core virus-like particles targeted and inhibited tumor cell migration and invasion.

We used a baculovirus expression system to express fusion proteins of HCV core, RGD (Arg-Gly-Asp) peptide, and IFN-α2a fragments in Sf9 cells. Western blotting and electron microscopy demonstrate that HCV core, peptides RGD, and IFN-α2a fusion proteins assemble into 30 to 40 nm nano-particles (virus-like particles, VLPs). Xenograft assays show that VLPs greatly reduced tumor volume and weight with regard to a nontreated xenograft. Migration and invasion results show that VLPs can inhibit the migration and invasion of the breast cancer cells MDA-MB231. This study will provide theoretical and experimental basis for the establishment of safe and effective tumor-targeted drug delivery systems and clinical application of VLPs carrying cell interacting cargo.