microRNA-377 acts as a suppressor in esophageal squamous cell carcinoma through CBX3-dependent P53/P21 pathway

Non‑coding RNA: A promising diagnostic biomarker and therapeutic target for esophageal squamous cell carcinoma (Review)

Esophageal cancer (EC) is a common form of malignant tumor in the digestive system that is classified into two types: Esophageal squamous cell carcinomas (ESCC) and esophageal adenocarcinoma. ESCC is known for its early onset of symptoms, which can be difficult to identify, as well as its rapid progression and tendency to develop drug resistance to chemotherapy and radiotherapy. These factors contribute to the high incidence of disease and low cure rate. Therefore, a diagnostic biomarker and therapeutic target need to be identified for ESCC. Non-coding RNAs (ncRNAs) are a class of molecules that are transcribed from DNA but do not encode proteins. Initially, ncRNAs were considered to be non-functional segments generated during transcription. However, with advancements in high-throughput sequencing technologies in recent years, ncRNAs have been associated with poor prognosis, drug resistance and progression of ESCC. The present study provides a comprehensive overview of the biogenesis, characteristics and functions of ncRNAs, particularly focusing on microRNA, long ncRNAs and circular RNAs. Furthermore, the ncRNAs that could potentially be used as diagnostic biomarkers and therapeutic targets for ESCC are summarized to highlight their application value and prospects in ESCC.

PLCD3 promotes malignant cell behaviors in esophageal squamous cell carcinoma via the PI3K/AKT/P21 signaling

BACKGROUND

Phospholipase C Delta 3 (PLCD3) is a member of phospholipase C(PLC) Protein and PLCD3 protein plays a prominent role in many cancers. However, little is known about the role of PLCD3 in esophageal squamous cell carcinoma (ESCC).

MATERIAL AND METHODS

We analyzed PLCD3 mRNA and protein expression in ESCC tissues and cell lines by immunohistochemistry, quantitative real-time PCR, and western blot. The correlation between PLCD3 expression and clinicopathological characteristics was also analyzed. CCK8, colony formation, wound-healing, and transwell assays were conducted to measure cell functional alternations. Flow cytometry was performed to assess the apoptosis rate and cell cycle caused by PLCD3 knockdown. Xenograft models in nude mice to clarify the role of PLCD3 in ESCC. Key proteins in the PI3K / AKT signaling pathway after treatment of ECA109 and KYSE150 cells with the AKT inhibitor MK2206 were analyzed by western blot.

RESULTS

PLCD3 was highly expressed in ESCC tissues and cell lines. PLCD3 expression levels correlated with pathologic stage and lymphatic metastasis. PLCD3 knockdown inhibited cell proliferation, migration, invasion, promoted apoptosis, and caused the cell cycle arrest in the G1 phase. PLCD3 overexpression promoted cell proliferation, migration, and invasion. In vivo experiments with xenografts demonstrated that PLCD3 promoted ESCC tumorigenesis. Finally, Overexpression of PLCD3 activated the PI3K / AKT / P21 signaling.

CONCLUSION

PLCD3 promotes malignant cell behaviors in esophageal squamous cell carcinoma via the PI3K/AKT/P21 signaling and could serve as a potential target for ESCC treatment.

Circ_0035381 Regulates Acute Myeloid Leukemia Development by Modulating YWHAZ Expression via Adsorbing miR-582-3p

Acute myeloid leukemia (AML) is a common hematopoietic disorder. Many circular RNAs (circRNAs) are abnormally expressed in AML, including hsa_circ_0035381 (circ_0035381). Nevertheless, the function and mechanism of circ_0035381 in AML remain mostly unclear. Expression of circ_0035381 was determined by qRT-PCR. The impacts of circ_0035381 on AML cell proliferation, apoptosis, and mitochondrial damage were validated via performing loss-of-function experiments. Targeting relationship was predicted by bioinformatics analysis and verified via dual-luciferase reporter and RNA immunoprecipitation assays. Circ_0035381 was upregulated in AML bone marrow samples and cells. Circ_0035381 downregulation decreased AML cell growth in nude mice and restrained AML cell proliferation and contributed to AML apoptosis and mitochondrial damage in vitro. Circ_0035381 acted as a miR-582-3p sponge, and miR-582-3p downregulation mitigated the impacts of circ_0035381 interference on AML cell proliferation, apoptosis, and mitochondrial damage. MiR-582-3p targeted Tyrosine3-monooxygenase/tryptophan5-monooxygenase activation protein zeta (YWHAZ), and it restrained AML cell proliferation and facilitated AML cell apoptosis and mitochondrial damage by decreasing YWHAZ expression. Notably, circ_0035381 regulated YWHAZ expression via miR-582-3p. Circ_0035381 knockdown repressed cell proliferation and promoted cell apoptosis and mitochondrial damage via regulating the miR-582-3p/YWHAZ axis in AML.

MicroRNA-377: A therapeutic and diagnostic tumor marker

Cancer is considered as one of the main causes of human deaths globally. Despite the recent progresses in therapeutic modalities, there is still a high rate of mortality among cancer patients. Late diagnosis in advanced tumor stages is one of the main reasons for treatment failure in cancer patients. Therefore, it is required to suggest the novel strategies for the early tumor detection. MicroRNAs (miRNAs) have critical roles in neoplastic transformation by regulation of cell proliferation, migration, and apoptosis. They are always considered as non-invasive markers due to their high stability in body fluids. Since, all of the miRNAs have tissue-specific functions in different tumors as tumor suppressor or oncogene; it is required to investigate the molecular mechanisms of every miRNA in different tumors to introduce that as a suitable non-invasive diagnostic marker in cancer patients. For the first time in the present review, we discussed the role of miR-377 during tumor progression. It has been reported that miR-377 mainly functions as a tumor suppressor through the regulation of signaling pathways and transcription factors. This review is an important step toward introducing the miR-377 as a novel diagnostic marker as well as a therapeutic target in cancer patients.

Mining Transcriptomic Data to Uncover the Association between CBX Family Members and Cancer Stemness

Genetic and epigenetic changes might facilitate the acquisition of stem cell-like phenotypes of tumors, resulting in worse patients outcome. Although the role of chromobox (CBX) domain proteins, a family of epigenetic factors that recognize specific histone marks, in the pathogenesis of several tumor types is well documented, little is known about their association with cancer stemness. Here, we have characterized the relationship between the CBX family members' expression and cancer stemness in liver, lung, pancreatic, and uterine tumors using publicly available TCGA and GEO databases and harnessing several bioinformatic tools (i.e., Oncomine, GEPIA2, TISIDB, GSCA, UALCAN, R2 platform, Enrichr, GSEA). We demonstrated that significant upregulation of CBX3 and downregulation of CBX7 are consistently associated with enriched cancer stem-cell-like phenotype across distinct tumor types. High CBX3 expression is observed in higher-grade tumors that exhibit stem cell-like traits, and CBX3-associated gene expression profiles are robustly enriched with stemness markers and targets for c-Myc transcription factor regardless of the tumor type. Similar to high-stemness tumors, CBX3-overexpressing cancers manifest a higher mutation load. On the other hand, higher-grade tumors are characterized by the significant downregulation of CBX7, and CBX7-associated gene expression profiles are significantly depleted with stem cell markers. In contrast to high-stemness tumors, cancer with CBX7 upregulation exhibit a lower mutation burden. Our results clearly demonstrate yet unrecognized association of high CBX3 and low CBX7 expression with cancer stem cell-like phenotype of solid tumors.

mTOR is involved in LRP5-induced osteogenic differentiation of normal and aged periodontal ligament stem cells in vitro

Periodontal ligament stem cells (PDLSCs) plays an important role in tissue engineering. As the age increased, the cell viability and osteogenic differentiation of PDLSCs all decreased. Low density lipoprotein receptor related protein 5 (LRP5) was found to promote bone marrow mesenchymal stem cells osteogenic differentiation. Therefore, our study explored the effect of LRP5 on normal and aged PDLSCs and relative mechanism. Here, we found that the expression of LRP5 in PDLSCs of 24 week-old mice was decreased compared with PDLSCs of 5 week-old mice (n = 5). . LRP5 overexpression in PDLSCs increased the intensity of alkaline phosphatase and alizarin red staining, accompanied with upregulated the levels of RUNX family transcription factor 2, collagen type I, and β-Catenin. LRP5 knockdown displayed the opposite results in PDLSCs in vitro. LRP5 overexpression in aged PDLSCs restored part ability of osteogenic differentiation. Meantime, LRP5 increased the protein expression of phosphorylation of mammalian target of rapamycin (p-mTOR) in normal and aged PDLSCs. Immunofluorescence showed that LRP5 increased the accumulation of p-mTOR nucleus. The effect of LRP5 in promoting osteogenic differentiation of PDLSCs can be antagonized by mTOR inhibitor rapamycin. These findings suggest that LRP5 positively regulate osteogenic differentiation of normal and aged PDLSCs and may be a potential target for enlarging the application of PDLSCs in tissue regeneration.

Nanog, as a key cancer stem cell marker in tumor progression

Cancer stem cells (CSCs) are a small population of malignant cells that induce tumor onset and development. CSCs share similar features with normal stem cells in the case of self-renewal and differentiation. They also contribute to chemoresistance and metastasis of cancer cells, leading to therapeutic failure. To identify CSCs, multiple cell surface markers have been characterized, including Nanog, which is found at high levels in different cancers. Recent studies have revealed that Nanog upregulation has a substantial association with the advanced stages and poor prognosis of malignancies, playing a pivotal role through tumorigenesis of multiple human cancers, including leukemia, liver, colorectal, prostate, ovarian, lung, head and neck, brain, pancreatic, gastric and breast cancers. Nanog through different signaling pathways, like JAK/STAT and Wnt/β-catenin pathways, induces stemness, self-renewal, metastasis, invasiveness, and chemoresistance of cancer cells. Some of these signaling pathways are common in various types of cancers, but some have been found in one or two cancers. Therefore, this review aimed to focus on the function of Nanog in multiple cancers based on recent studies surveying the suitable approaches to target Nanog and inhibit CSCs residing in tumors to gain favorable results from cancer treatments.

Regulation of ferroptosis by noncoding RNAs: a novel promise treatment in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a highly prevalent tumor that requires extensive research. Ferroptosis is a unique cell death modality driven by iron-dependent phospholipid peroxidation manifested as an accumulation of lipid-reactive oxygen species. With further understanding of noncoding RNAs (ncRNAs), numerous studies have demonstrated an important regulatory role of ncRNAs in ESCC through ferroptosis, including microRNAs, long ncRNAs, and circular RNAs. These ncRNAs influence the expression of the target gene to regulate ESCC progression by involving the ferroptosis signaling pathway. However, the specific regulatory mechanism of ncRNAs on ferroptosis in ESCC remains largely unknown. This review summarized the current knowledge on the relation between ferroptosis regulators, such as glutathione synthesis/metabolism, Keap1/Nfr2, and p53, by ncRNAs and ESCC. This review also proposed the possible therapeutic approaches for ncRNAs targeting ferroptosis in ESCC. This is the latest and most effective summary of recent research achievements of ncRNAs on ferroptosis in ESCC. These ncRNAs based on ferroptosis merit further investigation in preclinical research of ESCC.

CBX3 is a Prognostic Biomarker Correlated with ATR Activation and Immune Infiltration in Head and Neck Squamous Cell Carcinoma

BACKGROUND

Chromobox protein homolog (CBX) family members play important roles in the progression and prognosis of many cancers. However, their functional role in head and neck squamous cell carcinoma (HNSCC) remains largely unknown.

METHODS

In this study, we analyzed the expression and functions of CBX family members using The Cancer Genome Atlas data. Most CBX family members were found to be differentially expressed in various tumors, including HNSCC, compared to normal tissues. Multivariate Cox regression analysis showed that CBX3 expression is an independent prognostic factor for HNSCC patients. A nomogram based on CBX3 expression was constructed for use as a diagnostic indicator for HNSCC patients. We also used qPCR to validate the expression of CBX3.

RESULTS

Gene set enrichment analysis suggested that CBX3 participates in ataxia-telangiectasia mutated and Rad3-related protein kinase (ATR) activation and tumor progression. Analysis of immune infiltration indicated that CBX3 expression is negatively correlated with mast cells, DCs, immature DCs, and neutrophils.

CONCLUSION

Our findings show that high CBX3 expression predicts poor prognosis in HNSCC and that CBX3 may act as an oncoprotein by activating ATR and affecting immune infiltration.

Carnosic Acid Induces Antiproliferation and Anti-Metastatic Property of Esophageal Cancer Cells via MAPK Signaling Pathways

Background

Carnosic acid (CA) is a polyphenolic diterpene extracted from rosemary. Reports have shown that CA possesses anticancer activity. However, whether CA inhibits esophageal squamous cell carcinoma, an aggressive type of esophageal cancer, remains untested.

Methods

The effects of CA on cell survival, migration, and apoptosis were evaluated by a combination of MTT, colony formation assay, flow cytometry, and Transwell assay. The potential signaling pathways involved were investigated via Western blot assay.

Results

CA dose-dependently inhibited cell proliferation, apoptosis, migration, and colony formation. Mechanistically, CA arrested the cell cycle at G2/M phase, promoted cell apoptosis, induced DNA damage, and inhibited the MAPK signaling pathways.

Conclusion

Our results suggest that CA is a potential anticancer drug for esophageal squamous cell carcinoma.

Smoking-associated upregulation of CBX3 suppresses ARHGAP24 expression to activate Rac1 signaling and promote tumor progression in lung adenocarcinoma

Although tobacco smoking is a risk factor for lung adenocarcinoma (LUAD), the mechanisms by which tobacco smoking induces LUAD development remain elusive. Histone methylation levels in human bronchial epithelial cells have been reported to increase after exposure to cigarettes. In this study, we explored the mechanisms regulating histone methylation in LUAD in response to smoking. We found that the histone H3K9 methylation reader CBX3 was upregulated in current smokers with LUAD, and that CBX3 overexpression promoted LUAD progression. Functional enrichment analyses revealed that CBX3 regulated the activation of Rho GTPases in LUAD. We also found that by forming a complex with TRIM28, TRIM24, and RBBP4, CBX3 repressed the expression of ARHGAP24 and increased the amount of active Rac1 in LUAD cells. Collectively, these results suggest that smoking associated upregulation of CBX3 promotes LUAD progression by activating the ARHGAP24/Rac1 pathway. Hence, the CBX3/ARHGAP24/Rac1 axis may represent a promising therapeutic target in smoking-induced LUAD.

Roles of microRNAs in tumorigenesis and metastasis of esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is the major subtype of esophageal cancer that is prevalent in Eastern Asia. Despite recent advances in therapy, the outcome of ESCC patients is still dismal. MicroRNAs (miRNAs) are non-coding RNAs which can negatively modulate gene expression at the post-transcriptional level. The involvement and roles of miRNAs have become one of the hot topics of cancer research in recent years. In ESCC, genetic variations within miRNA coding genes were found to have distinct epidemiological significance in different populations. Dysregulated expression of several miRNAs was reported to be associated with therapeutic response. Functionally, miRNAs can act either in an oncogenic or a tumor-suppressive manner during tumorigenesis of ESCC by interrupting signaling pathways associated with cell proliferation, metabolism, cancer stemness, and resistance to chemo- or radiotherapy. Moreover, miRNAs modulate metastasis of ESCC by targeting genes that regulate cytoskeleton dynamics, extracellular matrix remodeling, epithelial-mesenchymal transition, and tumor microenvironment. Most importantly, mounting evidence suggests that inhibiting oncogenic miRNAs or restoring the loss of tumor-suppressive miRNAs has therapeutic potential in the treatment of ESCC. Here, we review and discuss recent studies on the significance, biological functions, and therapeutic potential of miRNAs in tumorigenesis and metastasis of ESCC.

APEX1/miR-24 axis: a promising therapeutic target in endometriosis

PURPOSE

The present work aimed to explore the aberrant expression of APEX1 in endometrial stromal cells (ESC) and the underlying mechanisms.

METHODS

The levels of APEX1 and miR-24 in endometriosis tissues were tested by qRT-PCR and Western blot. After cell transfection, cells were correspondingly classified into pcDNA3.1-NC, sh-NC, mimic NC, inhibitor NC, pcDNA3.1-APEX1, sh-APEX1, miR-24 mimic, miR-24 inhibitor, sh-NC + inhibitor NC, inhibitor-NC + sh-APEX1, sh-NC + miR-24 inhibitor, pcDNA3.1-NC + mimic NC, mimic NC + pcDNA3.1-APEX1 and pcDNA3.1-NC + miR-24 mimic group. Besides, cell proliferation, apoptosis in addition to apoptosis-related proteins Bax, Bcl-2 and cleaved-casase-3 were analyzed by BrdU assay, flow cytometry (FCM) and Western blot assays, respectively. Additionally, RIP assay was conducted to determine the interaction between pri-miR-24 and miR-24.

RESULTS

APEX1 and miR-24 were highly expressed in endometriosis tissues. Overexpression of APEX1 and miR-24 potentiates ESC proliferation and inhibits apoptosis, while those effects could be reversed by APEX1 and miR-24 silencing. Meanwhile, APEX1 and miR-24 could elevate ESC apoptosis-related proteins Bax and cleaved-caspase-3 and decrease Bcl-2 expression. Importantly, APEX1 was positively correlated with miR-24 expression.

CONCLUSION

APEX1 promotes ESC proliferation and inhibits apoptosis by upregulating miR-24 expression.