RASSF6-TRIM16 axis promotes cell proliferation, migration and invasion in esophageal squamous cell carcinoma

CircMALAT1 promotes cancer stem-like properties and chemoresistance via regulating Musashi-2/c-Myc axis in esophageal squamous cell carcinoma

The primary challenge in treating esophageal squamous cell carcinoma (ESCC) is resistance to chemotherapy. Cancer stem cell (CSC) is the root cause of tumor drug resistance. Therefore, targeting CSCs has been considered promising therapeutic strategy for tumor treatment. Here, we report that circMALAT1 was significantly upregulated in ESCC CSC-like cells and primary tumors from ESCC patients. Clinically, there was a positive correlation between circMALAT1 expression and ESCC stage and lymph node metastasis, as well as poor prognosis for ESCC patients. In vitro and in vivo functional studies revealed that circMALAT1 promoted CSC-like cells expansion, tumor growth, lung metastasis and drug resistance of ESCC. Mechanistically, circMALAT1 directly interacted with CSC-functional protein Musashi RNA Binding Protein 2 (MSI2). CircMALAT1 inhibited MSI2 ubiquitination by preventing it from interacting with β-transducin repeat containing protein (BTRC) E3 ubiquitin ligase. Also, circMALAT1 knockdown inhibited the expression of MSI2-regulating CSC-markers c-Myc in ESCC. Collectively, circMALAT1 modulated the ubiquitination and degradation of the MSI2 protein signaling with ESCC CSCs and accelerated malignant progression of ESCC. CircMALAT1 has the potential to serve as a biomarker for drug resistance and as a target for therapy in CSCs within ESCC.

AKAP12 inhibits esophageal squamous carcinoma cell proliferation, migration, and cell cycle via the PI3K/AKT signaling pathway

Esophageal squamous cell carcinoma (ESCC) consistently ranks as one of the most challenging variants of squamous cell carcinomas, primarily due to the lack of effective early detection strategies. We herein aimed to elucidate the underlying mechanisms and biological role associated with A-kinase anchoring protein 12 (AKAP12) in the context of ESCC. Bioinformatic analysis had revealed significantly lower expression level of AKAP12 in ESCC tissue samples than in their non-cancerous counterparts. To gain deeper insights into the potential role of AKAP12 in the progression of ESCC, we conducted a single-gene set enrichment analysis of AKAP12 on ESCC datasets. Our findings suggested that AKAP12 exhibits functions inhibiting cell cycle progression, tumor proliferation, and epithelial-mesenchymal transition. To further validate our findings, we subjected ESCC cell lines to AKAP12 overexpression using CRISPR/Cas9-SAM. In vitro analyses demonstrated that increased expression of AKAP12 significantly reduced cell proliferation, migration, and cell cycle progression. Simultaneously, genes associated with this biological role undergo corresponding regulatory shifts. These observations provided valuable insights into the biological role played by AKAP12 in ESCC progression. In summary, AKAP12 shows promise as a new potential biomarker for early ESCC diagnosis, offering potential advantages for subsequent therapeutic intervention and disease management.

Intricate confrontation: Research progress and application potential of TRIM family proteins in tumor immune escape

BACKGROUND

Tripartite motif (TRIM) family proteins have more than 80 members and are widely found in various eukaryotic cells. Most TRIM family proteins participate in the ubiquitin-proteasome degradation system as E3-ubiquitin ligases; therefore, they play pivotal regulatory roles in the occurrence and development of tumors, including tumor immune escape. Due to the diversity of functional domains of TRIM family proteins, they can extensively participate in multiple signaling pathways of tumor immune escape through different substrates. In current research and clinical contexts, immune escape has become an urgent problem. The extensive participation of TRIM family proteins in curing tumors or preventing postoperative recurrence and metastasis makes them promising targets.

AIM OF REVIEW

The aim of the review is to make up for the gap in the current research on TRIM family proteins and tumor immune escape and propose future development directions according to the current progress and problems.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This up-to-date review summarizes the characteristics and biological functions of TRIM family proteins, discusses the mechanisms of TRIM family proteins involved in tumor immune escape, and highlights the specific mechanism from the level of structure-function-molecule-pathway-phenotype, including mechanisms at the level of protein domains and functions, at the level of molecules and signaling pathways, and at the level of cells and microenvironments. We also discuss the application potential of TRIM family proteins in tumor immunotherapy, such as possible treatment strategies for combination targeting TRIM family protein drugs and checkpoint inhibitors for improving cancer treatment.

Role of the tripartite motif (TRIM) family in female genital neoplasms

The tripartite motif proteins (TRIMs) family represents a class of highly conservative proteins which play a large regulatory role in molecular processes. Recently, increasing evidence has demonstrated a role of TRIMs in female genital neoplasms. Our review thereby aimed to provide an overview of the biological involvement of TRIMs in female genital neoplasms, to provide a better understanding of its role in the development and progression of such diseases, and emphasize its potential as targeted cancer therapy. Overall, our review highlighted that the wide-ranging roles of TRIMs, in not only target protein ubiquitination, tumor migration and/or invasion, epithelial-mesenchymal transition, stemness, cell adhesion, proliferation, cell cycle regulation, and apoptosis, but also in influencing estrogenic, and chemotherapy response.

Deubiquitylase PSMD14 inhibits autophagy to promote ovarian cancer progression via stabilization of LRPPRC

Autophagy is a key cellular process, which exists in many tumors and plays dual roles in tumor promotion and suppression. However, the role and mechanism of aberrant autophagy in ovarian cancer remains unclear. Ubiquitin-proteasome pathway is the most important pathway for specific protein degradation. Deubiquitinases (DUBs) have crucial roles in all the stages of tumorigenesis and progression. Herein, we explore the DUBs which contribute to aberrant autophagy in ovarian cancer. TCGA data analysis shows that the autophagy level is suppressed, and the selective autophagy receptor SQSTM1/p62 is abnormally high expressed in ovarian cancer. We screen and identify that the deubiquitinase PSMD14 negatively regulates autophagy level. Functional studies show that increased PSMD14 expression remarkably enhances ovarian cancer cells malignancy, whereas knockdown of PSMD14 has the opposite effect. Furthermore, in vivo assays show that knockdown of PSMD14 inhibits the growth, lung and abdominal metastasis of ovarian cancer. Mechanistically, PSMD14 directly interacts with LRPPRC and inhibits its ubiquitination, thereby inhibiting autophagy through LRPPRC/Beclin1-Bcl-2/SQSTM1 signaling pathway. Next, we demonstrate that PSMD14 is upregulated in ovarian cancer and high expression of PSMD14 positively correlates with LRPPRC. Taken together, we clarify the role of autophagy in regulating the ovarian cancer phenotype and provide insights into regulatory mechanism of autophagy in ovarian cancer.

Regulation of RASSF by non-coding RNAs in different cancers

Ras-association domain family (RASSF) proteins are tumor suppressors and have gained phenomenal limelight because of their mechanistic role in the prevention/inhibition of carcinogenesis and metastasis. Decades of research have demystified wide ranging activities of RASSF molecules in multiple stages of cancers. Although major fraction of RASSF molecules has tumor suppressive roles, yet there is parallel existence of proof-of-concept about moonlighting activities of RASSF proteins as oncogenes. RASSF proteins tactfully rewire signaling cascades for prevention of cancer and metastasis but circumstantial evidence also illuminates oncogenic role of different RASSF proteins in different cancers. In this review we have attempted to provide readers an overview of the complex interplay between non-coding RNAs and RASSF proteins and how these versatile regulators shape the landscape of carcinogenesis and metastasis.

Pharmacological Modulation of Ubiquitin-Proteasome Pathways in Oncogenic Signaling

The ubiquitin-proteasome pathway (UPP) is involved in regulating several biological functions, including cell cycle control, apoptosis, DNA damage response, and apoptosis. It is widely known for its role in degrading abnormal protein substrates and maintaining physiological body functions via ubiquitinating enzymes (E1, E2, E3) and the proteasome. Therefore, aberrant expression in these enzymes results in an altered biological process, including transduction signaling for cell death and survival, resulting in cancer. In this review, an overview of profuse enzymes involved as a pro-oncogenic or progressive growth factor in tumors with their downstream signaling pathways has been discussed. A systematic literature review of PubMed, Medline, Bentham, Scopus, and EMBASE (Elsevier) databases was carried out to understand the nature of the extensive work done on modulation of ubiquitin-proteasome pathways in oncogenic signaling. Various in vitro, in vivo studies demonstrating the involvement of ubiquitin-proteasome systems in varied types of cancers and the downstream signaling pathways involved are also discussed in the current review. Several inhibitors of E1, E2, E3, deubiquitinase enzymes and proteasome have been applied for treating cancer. Some of these drugs have exhibited successful outcomes in in vivo studies on different cancer types, so clinical trials are going on for these inhibitors. This review mainly focuses on certain ubiquitin-proteasome enzymes involved in developing cancers and certain enzymes that can be targeted to treat cancer.

Dissecting the DNA binding landscape and gene regulatory network of p63 and p53

The transcription factor p53 is the best-known tumor suppressor, but its sibling p63 is a master regulator of epidermis development and a key oncogenic driver in squamous cell carcinomas (SCC). Despite multiple gene expression studies becoming available, the limited overlap of reported p63-dependent genes has made it difficult to decipher the p63 gene regulatory network. Particularly, analyses of p63 response elements differed substantially among the studies. To address this intricate data situation, we provide an integrated resource that enables assessing the p63-dependent regulation of any human gene of interest. We use a novel iterative de novo motif search approach in conjunction with extensive ChIP-seq data to achieve a precise global distinction between p53-and p63-binding sites, recognition motifs, and potential co-factors. We integrate these data with enhancer:gene associations to predict p63 target genes and identify those that are commonly de-regulated in SCC representing candidates for prognosis and therapeutic interventions.

Downregulation of miR-7-5p Inhibits the Tumorigenesis of Esophagus Cancer via Targeting KLF4

Background

Esophageal cancer (EC) is one of the aggressive gastrointestinal malignancies. It has been reported that microRNAs (miRNAs) play key roles during the tumorigenesis of EC. To identify novel potential targets for EC, differential expressed miRNAs (DEG) between EC and adjacent normal tissues were analyzed with bioinformatics tool.

Methods

The differential expression of miRNAs between EC and adjacent normal tissues was analyzed. CCK-8 and Ki67 staining were used to detect the cell proliferation. Flow cytometry was performed to test the cell apoptosis. The correlation between miR-7-5p and KLF4 was detected by dual-luciferase report assay. Gene and protein expression in EC cells or in tissues were measured by qRT-PCR and Western blot, respectively. Cell migration and invasion were detected with transwell assay. Xenograft mice model was established to investigate the role of miR-7-5p in EC tumorigenesis in vivo.

Results

MiR-7-5p was found to be negatively correlated with the survival rate of patient with EC. In addition, downregulation of miR-7-5p significantly inhibited the growth and invasion of EC cells. Meanwhile, miR-7-5p directly targeted KLF4 in EC cells. Moreover, downregulation of miR-7-5p inhibited the tumorigenesis of EC via inactivating MAPK signaling pathway in vivo.

Conclusion

Downregulation of miR-7-5p notably suppressed the progression of EC via targeting KLF4. Thus, miR-7-5p might serve as a new target for the treatment of EC.