Regulation of Cancer Stem Cell Self-Renewal by HOXB9 Antagonizes Endoplasmic Reticulum Stress-Induced Melanoma Cell Apoptosis via the miR-765-FOXA2 Axis

HOXB9 promotes laryngeal squamous cell carcinoma progression by upregulating MMP12

Transcriptional factor HOXB9, a part of the HOX gene family, plays a crucial role in the development of diverse cancer types. This study aimed to elucidate the regulatory mechanism of HOXB9 on the proliferation and invasion of laryngeal squamous cell carcinoma (LSCC) cells to provide guidance for the development and prognosis of LSCC. The CRISPR/Cas9 method was employed in LSCC cell lines to knock out the HOXB9 gene and validate its effects on the proliferation, migration, invasion, and regulation of LSCC cells. CCK-8 and flow cytometry were used to detect cell viability and proliferation; Tunnel was used to detect cell apoptosis, and transwell was used to detect cell migration and invasion. The effect of HOXB9 on tumor growth was tested in nude mice. The downstream target genes regulated by HOXB9 were screened by microarray analysis and verified by Western blotting, immunohistochemistry, chromatin immunoprecipitation, and double-luciferase reporter assays. The current research investigated molecular pathways governed by HOXB9 in the development of LSCC. Additionally, both laboratory- and living-organism-based investigations revealed that disrupting the HOXB9 gene through the CRISPR/CAS9 mechanism restrained cellular growth, movement, and infiltration, while enhancing cellular apoptosis. Detailed analyses of LSCC cell strains and human LSCC samples revealed that HOXB9 promoted LSCC progression by directly elevating the transcriptional activity of MMP12. HOXB9 could influence changes in LSCC cell functions, and the mechanism of action might be exerted through its downstream target gene, MMP12.

Gambogenic acid inhibits proliferation and ferroptosis by targeting the miR-1291/FOXA2 and AMPKα/SLC7A11/GPX4 axis in colorectal cancer

The present study aims to investigate the mechanism of the nature compound gambogenic acid (GNA) on the apoptosis and ferroptosis in colorectal cancer (CRC). The effect of GNA on the proliferation of CRC cell lines were detected by MTT and clonogenic assay. The xenograft tumor model was established, and the inhibition effect of GNA were evaluated by observing the tumor growth. The endoplasmic reticulum (ER) of HCT116 was observed by using the ER tracker. The TargrtScan database was used to predict the miRNA binding sites. The level of miRNA with GNA treatment was explored by real-time quantitative PCR. The effect of ferroptosis were evaluated by detect the expression of reactive oxygen species (ROS), intracellular ferrous iron (Fe2+ ), malondialdehyde (MDA), glutathione (GSH), subunit solute carrier family 7 member 11 (SLC7A11), glutathione peroxidase (GPX)4, transferrin, and ferritin by Western blot. GNA isolated from gamboge can inhibit the growth and proliferation of CRC cell lines in a concentration-dependent manner. GNA activated ER stress by upregulating miR-1291, and miR-1291 targeted the forkhead box protein A2 (FOXA2). GNA also induced ROS production and mediated the Fenton reaction by activating transferrin to increase Fe2+ , thus inducing ferroptosis. In addition, GNA could induce ferroptosis through the depletion of GSH and GPX4. Furthermore, GNA treatment regulated iron metabolism by activating AMPKα/SLC7A11/GPX4 signaling. In conclusion, GNA activated ER stress via miR-1291 and induced ferroptosis in CRC cells and might be a new inducer of ferroptosis, which can expand the efficacy of chemotherapy drugs.

Effect of photothermal and photodynamic therapy with cobalt ferrite superparamagnetic nanoparticles loaded with ICG and PpIX on cancer stem cells in MDA-MB-231 and A375 cell lines

BACKGROUND

Cancer cells are resistant to treatments such as chemotherapy and radiotherapy due to their characteristics such as self-renewal, high proliferation and other resistance mechanisms. To overcome this resistance, we combined a light-based treatment with nanoparticles to get advantage of both PDT and PTT in order to increase efficiency and beater outcome.

METHODS AND MATERIAL

After synthesis and characterization of CoFe2O4@citric@PEG@ICG@ PpIX NPs, their dark cytotoxicity concentration was determined with MTT assay. Then light-base treatments were performed by two different light source for MDA-MB-231 and A375 cell lines. After treatment, the results were evaluated 48 h and 24 h after treatment by MTT assay and flow cytometry. Among CSCs defined markers, CD44, CD24 and CD133 are the most widely-used markers in CSC research and are also therapeutic targets in cancers. So we used proper antibodies to detect CSCs. Then indexes like ED50, synergism defined to evaluated the treatment.

RESULTS

ROS production and temperature increase have a direct relationship with exposure time. In both cell lines, the death rate in combinational treatment (PDT/PTT) is higher than single treatment and the amount of cells with CD44+CD24- and CD133+CD44+ markers has decreased. According to the synergism index, conjugated NPs show a high efficiency in use in light-based treatments. This index was higher in cell line MDA-MB-231 than A375. And the ED50 is proof of the high sensitivity of A375 cell line compared to MDA-MB-231 in PDT and PTT.

CONCLUSION

Conjugated NPs along with combined photothermal and photodynamic therapies may play an important role in eradication CSCs.

FoxA2 is a reliable marker for the diagnosis of yolk sac tumour postpubertal-type

AIMS

Yolk sac tumour postpubertal-type (YSTpt) shows a wide range of histological patterns and is challenging to diagnose. Recently, forkhead box transcription factor A2 (FoxA2) emerged as a driver of YSTpt formation and a promising marker for diagnosing YSTpt. However, FoxA2 has not been tested in the different patterns of YSTpt. This study aimed to assess the staining pattern of FoxA2 in te different patterns of YSTpt and other germ cell tumours of the testis (GCTT), comparing it with glypican-3 (GPC3) and α-fetoprotein (AFP).

METHODS AND RESULTS

FOXA2, GPC3 and AFP immunohistochemistry was performed on 24 YSTpt (24 microcystic/reticular, 10 myxoid, two macrocystic, five glandular/alveolar, two endodermal sinus/perivascular, four solid, two polyembryoma/embryoid body and two polyvesicular vitelline) and 81 other GCTT. The percentage of positive cells (0, 1+, 2+, 3+) and the intensity (0, 1, 2, 3) were evaluated regardless of and within each YSTpt pattern. FoxA2 was positive in all YSTpt (24 of 24) and all but one (23 of 24) exhibited 2+/3+ stain, with higher intensity [median value (mv): 2.6] than AFP (1.8) and GPC3 (2.5). Both FoxA2 and GPC3 were positive in all microcystic/reticular (24 of 24), myxoid (10 of 10), macrocystic (two of two), endodermal sinus/perivascular (four of four) and polyembryoma/embryoid body (two of two) patterns. Nevertheless, only FoxA2 was positive in all glandular/alveolar (five of five), solid (four of four) and polyvesicular vitelline (two of two) patterns. The intensity of FoxA2 was higher than AFP and GPC3 in almost all YST patterns. In the other GCTT, FoxA2 was positive only in teratoma postpubertal-type (Tpt) [13 of 20 (65%)], with staining almost exclusively confined to the mature gastrointestinal/respiratory tract epithelium.

CONCLUSIONS

FoxA2 is a highly sensitive and specific biomarker that supports the diagnosis of YSTpt. FoxA2 is superior to GPC3 and AFP, especially in rare and difficult-to-diagnose histological patterns of YSTpt, but mature glands of Tpt could represent a potential diagnostic pitfall.

Homeobox B9 Promotes Colon Cancer Progression by Targeting SRSF3

BACKGROUND

Homeobox B9 (HOXB9) is one of the HOX family of transcription factors that are essential for cancer development and embryonic growth. However, the clinical importance and biological involvement of HOXB9 in colon cancer (CC) are not adequately understood.

AIMS

To investigate whether HOXB9 participates in the proliferation, invasion, and migration of CC.

METHODS

This study investigated the function and clinical significance of HOXB9 mRNA and protein expression in CC. Furthermore, overexpression and knockdown experiments of HOXB9 were developed to explore their effects on CC cell transwell and proliferation. Moreover, a molecular mechanism of HOXB9 regulate serine/arginine-rich splicing factor 3 (SRSF3) was explored.

RESULTS

HOXB9 expression was higher in CC cells and tissues at both the mRNA and protein levels. Poor survival in CC patients was significantly connected with high HOXB9 expression, which was also strongly associated with the TNM stage and lymph node metastases. Furthermore, in vitro CC cell proliferation, transwell were markedly aided by HOXB9 overexpression. Contrarily, HOXB9 knockdown had the reverse result and inhibited the formation of xenograft tumors in naked mice. Gene set enrichment analysis (GSEA) revealed a correlation between high HOXB9 expression and spliceosomes. JASPAR and GEPIA2.0, in addition to CHIP and dual-luciferase reporting assays, confirmed that HOXB9 targets the promoter of SRSF3 to enhance its expression. We also found that SRSF3 knockdown eliminated HOXB9 from cell proliferation and transwell.

CONCLUSION

We characterized the function and mechanism of HOXB9 in regulating colon cancer growth, suggesting a novel molecular approach for colon cancer-targeted therapy.

HOXB9 a miR-122-5p regulated gene, suppressed the anticancer effects of brassaol by upregulating SCD1 expression in melanoma

Brusatol (Bru), a Chinese medicine Brucea javanica extract, has a variety of antitumour effects. However, its role and underlying mechanism in melanoma have not been fully elucidated. In this study, we found that brusatol inhibited melanoma cell proliferation and migration and promoted cell apoptosis in vitro, in addition to suppressing melanoma cell tumorigenesis in vivo. Further studies on the mechanism revealed that brusatol significantly downregulated the expression of stearoyl-CoA desaturase 1 (SCD1). Increased SCD1 expression could impair the antitumour effects of brusatol on melanoma cells. Subsequently, we found that HOXB9, an important transcription factor, was directly bound to the promoter of SCD1, facilitating its transcription. Overexpression of HOXB9 inhibited brusatol-induced SCD1 reduction and promoted cell survival. Furthermore, our results revealed that miR-122-5p was significantly increased in response to brusatol treatment and led to a decrease in HOXB9 in melanoma. Collectively, our data suggested that the miR-122-5p/HOXB9/SCD1 axis might play an important role in the antitumour effects of brusatol and that brusatol might have potential clinical implications in melanoma therapy.

Forkhead box protein A2 alleviates toll-like receptor 4-mediated inflammation, endoplasmic reticulum stress, autophagy, and apoptosis induced by lipopolysaccharide in bovine hepatocytes

Lipopolysaccharide (LPS) is an important stimulus of inflammation via binding to toll-like receptor 4 (TLR4), but the role of TLR4 in LPS-induced cellular homeostasis disruption indicated by the increased level of endoplasmic reticulum (ER) stress, autophagy, and apoptosis is unknown in the liver of dairy cows. Previous studies show that forkhead box protein A2 (FOXA2) is an important transcriptional factor to maintain cellular metabolic homeostasis, but the mechanisms by which FOXA2 mediates cellular homeostasis disruption in response to LPS remains unclear. To achieve the aims, hepatocytes separated from dairy cows at ∼160 d in milk were pretreated with a specific TLR4 inhibitor TAK-242 for 12 h, followed by LPS treatment for another 12 h to investigate the role of TLR4 in LPS-induced disruption of cellular homeostasis. The results indicated that LPS-induced nuclear factor-κB (NF-κB)-mediated inflammatory cascades, ER stress, autophagy, and apoptosis via activating TLR4 and downregulating FOXA2 expression in bovine hepatocytes. The application of TLR4 inhibitor alleviated LPS-induced inflammation through inactivating NF-κB proinflammatory pathway, restored cell homeostasis by decreasing the level of ER stress, autophagy, and apoptosis, and upregulated FOXA2 expression. Furthermore, we also elevated FOXA2 expression with an overexpression plasmid to clarify its molecular role in response to LPS challenge. FOXA2 overexpression reduced LPS-caused inflammation by inhibiting NF-κB signaling pathway. Also, FOXA2 could alleviate ER stress to block unfolded protein response and suppress autophagic flux. In addition, FOXA2 enhanced mitochondrial membrane potential via reducing pro-apoptotic protein BAX, CASPASE3, and Cleaved CASPASE3 expression and elevating anti-apoptotic protein BCL-2 expression to mitigate LPS-induced apoptosis. Taken together, these findings suggested that FOXA2 is a mediator to alleviate TLR4-controlled inflammation, ER stress, autophagy, and apoptosis in LPS-treated bovine hepatocytes, it could serve as a potential target to intervene cell homeostasis disruption caused by LPS in the liver of dairy cows.

Long Noncoding RNA SAMMSON Promotes Melanoma Progression by Inhibiting FOXA2 Expression

Long noncoding RNAs (lncRNAs) play crucial roles in melanoma initiation and development, serving as potential therapeutic targets and prognostic markers for melanoma. lncRNA survival-associated mitochondrial melanoma-specific oncogenic noncoding RNA (SAMMSON) is upregulated in many types of human cancers. However, the functions of SAMMSON in melanoma have not been fully elucidated. This study is aimed at investigating the expression and functions of SAMMSON in melanoma development. Bioinformatics analysis was performed to determine the expression of SAMMSON and its correlation with the 10-year overall survival (OS) in melanoma patients. Cell proliferation, migration, invasion, and tumorigenesis were detected by MTT, colony formation, Transwell assays, and mouse xenograft model. The expression of cell cycle-related factors, epithelial-to-mesenchymal transition (EMT) makers, and matrix metalloproteinases (MMPs) was assessed by RT-qPCR and western blotting analysis. The results demonstrated that SAMMSON expression was upregulated in melanoma tissues and cells, and lower SAMMSON expression was correlated with longer 10-year OS. SAMMSON knockdown decreased the proliferation, migration, and invasion of melanoma cells by regulating the expression of proliferation-related genes, EMT factors, and MMPs, respectively. Additionally, Forkhead box protein A2 (FOXA2) was confirmed to be a target of SAMMSON, and the biological effects induced by FOXA2 overexpression were similar to those induced by SAMMSON silencing in melanoma cells. Further studies showed that SAMMSON downregulated FOXA2 expression in melanoma cells by modulating the EZH2/H3K27me3 axis. Taken together, our data indicate that SAMMSON plays an important role in melanoma progression and can be a valuable biomarker and therapeutic target in melanoma.

Emerging roles of endoplasmic reticulum stress in the cellular plasticity of cancer cells

Cellular plasticity is a well-known dynamic feature of tumor cells that endows tumors with heterogeneity and therapeutic resistance and alters their invasion-metastasis progression, stemness, and drug sensitivity, thereby posing a major challenge to cancer therapy. It is becoming increasingly clear that endoplasmic reticulum (ER) stress is a hallmark of cancer. The dysregulated expression of ER stress sensors and the activation of downstream signaling pathways play a role in the regulation of tumor progression and cellular response to various challenges. Moreover, mounting evidence implicates ER stress in the regulation of cancer cell plasticity, including epithelial-mesenchymal plasticity, drug resistance phenotype, cancer stem cell phenotype, and vasculogenic mimicry phenotype plasticity. ER stress influences several malignant characteristics of tumor cells, including epithelial-to-mesenchymal transition (EMT), stem cell maintenance, angiogenic function, and tumor cell sensitivity to targeted therapy. The emerging links between ER stress and cancer cell plasticity that are implicated in tumor progression and chemoresistance are discussed in this review, which may aid in formulating strategies to target ER stress and cancer cell plasticity in anticancer treatments.

Mechanism and Role of Endoplasmic Reticulum Stress in Osteosarcoma

Osteosarcoma is the most common malignant bone tumor, often occurring in children and adolescents. The etiology of most patients is unclear, and the current conventional treatment methods are chemotherapy, radiotherapy, and surgical resection. However, the sensitivity of osteosarcoma to radiotherapy and chemotherapy is low, and the prognosis is poor. The development of new and useful treatment strategies for improving patient survival is an urgent need. It has been found that endoplasmic reticulum (ER) stress (ERS) affects tumor angiogenesis, invasion, etc. By summarizing the literature related to osteosarcoma and ERS, we found that the unfolded protein response (UPR) pathway activated by ERS has a regulatory role in osteosarcoma proliferation, apoptosis, and chemoresistance. In osteosarcoma, the UPR pathway plays an important role by crosstalk with autophagy, oxidative stress, and other pathways. Overall, this article focuses on the relationship between ERS and osteosarcoma and reviews the potential of drugs or gene targets associated with ERS for the treatment of osteosarcoma.

Targeting oncogenic transcription factors in skin malignancies: An update on cancer stemness and therapeutic outcomes

The skin is the largest organ of the human body and prone to various diseases, including cancer; thus, provides the first line of defense against exogenous biological and non-biological agents. Skin cancer, a complex and heterogenic process, with steep incidence rate often metastasizes due to poor understanding of the underlying mechanisms of pathogenesis and clinical challenges. Indeed, accumulating evidence indicates that deregulation of transcription factors (TFs) due to genetic, epigenetic and signaling distortions plays essential role in the development of cutaneous malignancies and therapeutic challenges including cancer stemness features and reprogramming. This review highlights the recent developments exploring underlying mechanisms how deregulated TFs (e.g., NF-κB, AP-1, STAT etc.,) orchestrates cutaneous onco-pathogenesis, reprogramming, stemness and poor clinical outcomes. Along this line, bioactive drugs, and their derivatives from natural and or synthetic origin has gained attention due to their multitargeting potential, potentially safer and effective therapeutic outcome for human malignancies. We also discussed therapeutic importance of targeting aberrantly expressed TFs in skin cancers with bioactive natural products and or synthetic agents.

The placenta epigenome-brain axis: placental epigenomic and transcriptomic responses that preprogram cognitive impairment

Aim: The placenta-brain axis reflects a developmental linkage where disrupted placental function is associated with impaired neurodevelopment later in life. Placental gene expression and the expression of epigenetic modifiers such as miRNAs may be tied to these impairments and are understudied. Materials & methods: The expression levels of mRNAs (n = 37,268) and their targeting miRNAs (n = 2083) were assessed within placentas collected from the ELGAN study cohort (n = 386). The ELGAN adolescents were assessed for neurocognitive function at age 10 and the association with placental mRNA/miRNAs was determined. Results: Placental mRNAs related to inflammatory and apoptotic processes are under miRNA control and associated with cognitive impairment at age 10. Conclusion: Findings highlight key placenta epigenome-brain relationships that support the developmental origins of health and disease hypothesis.

Differentiation of crescent-forming kidney progenitor cells into podocytes attenuates severe glomerulonephritis in mice

Crescentic glomerulonephritis is characterized by vascular necrosis and parietal epithelial cell hyperplasia in the space surrounding the glomerulus, resulting in the formation of crescents. Little is known about the molecular mechanisms driving this process. Inducing crescentic glomerulonephritis in two Pax2Cre reporter mouse models revealed that crescents derive from clonal expansion of single immature parietal epithelial cells. Preemptive and delayed histone deacetylase inhibition with panobinostat, a drug used to treat hematopoietic stem cell disorders, attenuated crescentic glomerulonephritis with recovery of kidney function in the two mouse models. Three-dimensional confocal microscopy and stimulated emission depletion superresolution imaging of mouse glomeruli showed that, in addition to exerting an anti-inflammatory and immunosuppressive effect, panobinostat induced differentiation of an immature hyperplastic parietal epithelial cell subset into podocytes, thereby restoring the glomerular filtration barrier. Single-cell RNA sequencing of human renal progenitor cells in vitro identified an immature stratifin-positive cell subset and revealed that expansion of this stratifin-expressing progenitor cell subset was associated with a poor outcome in human crescentic glomerulonephritis. Treatment of human parietal epithelial cells in vitro with panobinostat attenuated stratifin expression in renal progenitor cells, reduced their proliferation, and promoted their differentiation into podocytes. These results offer mechanistic insights into the formation of glomerular crescents and demonstrate that selective targeting of renal progenitor cells can attenuate crescent formation and the deterioration of kidney function in crescentic glomerulonephritis in mice.

Circulating miR-1246 and miR-485-3p as Promising Biomarkers of Clinical Response and Outcome in Melanoma Patients Treated with Targeted Therapy

Despite the significant improvements in advanced melanoma therapy, there is still a pressing need for biomarkers that can predict patient response and prognosis, and therefore support rational treatment decisions. Here, we investigated whether circulating miRNAs could be biomarkers of clinical outcomes in patients treated with targeted therapy. Using next-generation sequencing, we profiled plasma miRNAs at baseline and at progression in patients treated with BRAF inhibitors (BRAFi) or BRAFi + MEKi. Selected miRNAs associated with response to therapy were subjected to validation by real-time quantitative RT-PCR . Receiver Operating Characteristics (ROC), Kaplan–Meier and univariate and multivariate Cox regression analyses were performed on the validated miR-1246 and miR-485-3p baseline levels. The median baseline levels of miR-1246 and miR-485-3p were significantly higher and lower, respectively, in the group of patients not responding to therapy (NRs) as compared with the group of responding patients (Rs). In Rs, a trend toward an increase in miR-1246 and a decrease in miR-485-3p was observed at progression. Baseline miR-1246 level and the miR-1246/miR-485-3p ratio showed a good ability to discriminate between Rs and NRs. Poorer PFS and OS were observed in patients with unfavorable levels of at least one miRNA. In multivariate analysis, a low level of miR-485-3p and a high miR-1246/miR-485-3p ratio remained independent negative prognostic factors for PFS, while a high miR-1246/miR-485-3p ratio was associated with an increased risk of mortality, although statistical significance was not reached. Evaluation of miR-1246 and miR-485-3p baseline plasma levels might help clinicians to identify melanoma patients most likely to be unresponsive to targeted therapy or at higher risk for short-term PFS and mortality, thus improving their management.

TRG16, targeted by miR-765, inhibits breast cancer stem cell-like properties via regulating the NF-κB pathway

Previous studies reported that cancer stem cells (CSCs) might be responsible for drug resistance and cancer progression. Transformation-Related Gene 16 Protein (TRG16), a pseudokinase, was reported to be a suppressor in some types of cancer and its overexpression impaired hepatocellular carcinoma cell stemness. However, the function of TRG16 in BC remains unclear. We found that TRG16 expression was significantly downregulated in BC tissues compared with adjacent tissues (n = 40; P < 0.001) and BC patients with lower expression of TRG16 had a worse prognosis. Forced expression of TRG16 inhibited BC stem cell-like properties as evidenced by decreased CD44-positive cells (CSC marker), reduced mammosphere quantity, and downregulated Nanog, aldehyde dehydrogenase, octamer-binding transcription factor 4, and SRY-box transcription factor 2 expression (CSC markers). Moreover, TRG16 overexpression inhibited self-renewal and invasion capabilities of BC cells in vitro as well as tumor growth in vivo but increased cisplatin sensitivity. However, TRG16 silencing had the opposite effects. Further mechanistic studies revealed that TRG16 was targeted and negatively regulated by miR-765, a facilitator of BC progression. TRG16 could suppress the activation of the NF-κB pathway in BC cells, which is a positive pathway in BC progression and contributes to the maintenance of cancer cell stemness. In conclusion, the results above demonstrate that TRG16, negatively regulated by miR-765, may inhibit the BC progression by regulating BC stem cell-like properties and this inhibition may be mediated by the NF-κB pathway. Our findings indicate that TRG16 may be a potential therapeutic targetable node for BC. TRG16, negatively regulated by miR-765, may inhibit the BC progression through regulating BC stem cell-like properties and this inhibition may be mediated by the NF-κB pathway.

HOXB9 blocks cell cycle progression to inhibit pancreatic cancer cell proliferation through the DNMT1/RBL2/c-Myc axis

Homeobox B9 (HOXB9) is involved in the occurrence and development of malignant tumors. However, the functions and underlying molecular mechanisms of HOXB9 in pancreatic cancer have yet to be identified. In this study, we find that both HOXB9 mRNA and protein levels are down-regulated in pancreatic cancer tissues and cell lines. Kaplan-Meier survival plots of 150 pancreatic cancer cases show that higher expression of HOXB9 in pancreatic cancer patients is associated with higher survival rates. We also find that over-expression of HOXB9 inhibits pancreatic cancer cell proliferation both in cell lines and the nude mouse xenograft as well as PDX models. Applying cell cycle PCR array analysis, Flow CytoMetry, ChIP-qPCR, and luciferase experiments, we observe that HOXB9 blocks cell cycle progression in the G0/G1 phase via up-regulating RBL2 and inhibiting c-Myc, and we further find that DNMT1 inhibits the expression of HOXB9 in pancreatic cancer by promoting the methylation of its promoter. Our findings highlight a novel mechanism of the DNMT1/HOXB9/RBL2/c-Myc pathway in regulating the cell cycle and proliferation of pancreatic cancer cells and provide a research basis for the prognosis and therapeutic application of HOXB9 in pancreatic cancer.

FOXA2 inhibits doxorubicin-induced apoptosis via transcriptionally activating HBP rate-limiting enzyme GFPT1 in HCC cells

Apoptosis plays an important role in both carcinogenesis and cancer treatment. Understanding the mechanisms through which resistance to apoptosis occurs in cancer cells has huge implications for cancer treatment. Although pieces of evidence have shown that elevated levels of global O-GlcNAcylation play an anti-apoptotic role in myriad cancers, the underlying mechanism is still ambiguous. In this study, we demonstrated that FOXA2, an essential transcription factor for liver homeostasis and hepatocellular carcinoma (HCC) development, inhibits doxorubicin (DOX)-induced apoptosis through elevating cellular O-GlcNAcylation in HCC cells. In response to DOX treatment, elevated FOXA2 and global O-GlcNAcylation level was observed in HCC cells, and higher FOXA2 levels indicated lower levels of DOX-induced apoptosis. Subsequently, we demonstrated that FOXA2 is a direct transcriptional activator of the hexosamine biosynthetic pathway (HBP) rate-limiting enzyme GFPT1. The upregulation of FOXA2 expression induced the synthesis of intracellular UDP-GlcNAc, which is the sugar substrate of O-GlcNAcylation produced by the HBP. The flux through the HBP elevated the global O-GlcNAcylation level and led to the activation of survival signaling pathways in HCC cells. Furthermore, GFPT1 was proved to be an important downstream regulator of FOXA2-mediated apoptotic suppression. These results provide insights into the molecular mechanism by which FOXA2 inhibits DOX-induced HCC cell apoptosis and suggest that targeting FOXA2 might offer a new strategy for HCC treatment.

Artesunate combined with verteporfin inhibits uveal melanoma by regulation of the MALAT1/yes-associated protein signaling pathway

Uveal melanoma (UM) is the most common ocular malignancy and has no effective clinical treatment. Therefore, novel drugs to suppress UM tumor progression are urgently required. The present study aimed to clarify the underlying mechanism of the inhibitory effects of artesunate on UM. By using plasmid transfection and detecting apoptotic level, the present study identified artesunate as a potential candidate for UM treatment. Compared with those in the vehicle (DMSO)-treated control cells, artesunate enhanced the apoptotic rate and increased lactate dehydrogenase release, reactive oxygen species and IL1b and IL18 levels in C918 cells. Overexpression of yes-associated protein (YAP) or metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in C918 cells reversed the effects of artesunate and reduced the apoptotic rate compared with those observed in cells transfected with the negative control plasmid. Notably, verteporfin enhanced the effects of artesunate on C918 cells by increasing the apoptotic rate, indicating that combined therapy was more effective compared with treatment with artesunate alone. In conclusion, the results of the present study demonstrated that artesunate elevated the apoptotic rate and suppressed C918 cell viability by regulating the MALAT1/YAP signaling pathway, and these effects were enhanced by supplementation with verteporfin. These results suggested that artesunate may exert an inhibitory effect on C918 cells and that the MALAT1/YAP signaling may serve important role in mediating these effects, providing evidence of its potential for treating UM in the clinic.

MicroRNAs at the Crossroad of the Dichotomic Pathway Cell Death vs. Stemness in Neural Somatic and Cancer Stem Cells: Implications and Therapeutic Strategies

Stemness and apoptosis may highlight the dichotomy between regeneration and demise in the complex pathway proceeding from ontogenesis to the end of life. In the last few years, the concept has emerged that the same microRNAs (miRNAs) can be concurrently implicated in both apoptosis-related mechanisms and cell differentiation. Whether the differentiation process gives rise to the architecture of brain areas, any long-lasting perturbation of miRNA expression can be related to the occurrence of neurodevelopmental/neuropathological conditions. Moreover, as a consequence of neural stem cell (NSC) transformation to cancer stem cells (CSCs), the fine modulation of distinct miRNAs becomes necessary. This event implies controlling the expression of pro/anti-apoptotic target genes, which is crucial for the management of neural/neural crest-derived CSCs in brain tumors, neuroblastoma, and melanoma. From a translational point of view, the current progress on the emerging miRNA-based neuropathology therapeutic applications and antitumor strategies will be disclosed and their advantages and shortcomings discussed.

Interplay between endoplasmic reticulum stress and non-coding RNAs in cancer

To survive, cancer cells are subjected to various internal and external adverse factors, including genetic mutations, hypoxia, nutritional deficiencies, and drug toxicity. All of these factors result in the accumulation of unfolded proteins in the endoplasmic reticulum, which leads to a condition termed endoplasmic reticulum stress (ER stress) and triggers the unfolded protein response (UPR). UPR downstream components strictly control transcription and translation reprogramming to ensure selective gene expression, including that of non-coding RNA (ncRNAs), to adapt to adverse environments. NcRNAs, including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), play important roles in regulating target gene expression and protein translation, and their aberrant expression is related to tumor development. Dysregulation of ncRNAs is involved in the regulation of various cellular characteristics of cancer cells, including growth, apoptosis, metastasis, angiogenesis, drug sensitivity, and tumor stem cell properties. Notably, ncRNAs and ER stress can regulate each other and collaborate to determine the fate of tumor cells. Therefore, investigating the interaction between ER stress and ncRNAs is crucial for developing effective cancer treatment and prevention strategies. In this review, we summarize the ER stress-triggered UPR signaling pathways involved in carcinogenesis followed by the mutual regulation of ER stress and ncRNAs in cancer, which provide further insights into the understanding of tumorigenesis and therapeutic strategies.

LncRNA FOXD3-AS1 knockdown protects against cerebral ischemia/reperfusion injury via miR-765/BCL2L13 axis

AIMS

Long non-coding RNAs (lncRNAs) FOXD3-AS1 was reported to be increased in cardiomyocyte ischemic injury. However, its role and underlying molecular mechanism in ischemic stroke remain unknown. This study was to investigate the role of FOXD3-AS1 in cerebral ischemia/reperfusion injury.

METHODS

The expression of FOXD3-AS1 and miR-765 were measured with qRT-PCR. The shared putative miR-765 binding sites both in BCL2L13 and FOXD3-AS1 were identified with bioinformatics, luciferase reporter assay and RNA immunoprecipitation. Apoptosis and its related proteins were detected by TUNEL assay, Hoechst 33,258 staining, flow cytometry and western blot. Infarct volume and the neurological status were evaluated with TTC staining and neurologic deficit score, respectively.

RESULTS

The up-regulation of FOXD3-AS1 and down-regulation of miR-765 were found in both mouse brains after cerebral ischemia/reperfusion (I/R) and neuroblastoma cells of neuro-2A (N2a) after oxygen-glucose deprivation/reoxygenation (OGD/R). Moreover, the overexpression of miR-765 reduced N2a cell apoptosis caused by OGD/R. MiR-765 could target BCL2L13 directly. In addition, we found that FOXD3-AS1 bound to miR-765 directly, acting as a ceRNA to modulate the expression of BCL2L13. Overexpression of FOXD3-AS1 antagonized the inhibitory impact of miR-765 on the expression of BCL2L13 and the apoptosis of N2a cells treated with OGD/R, while FOXD3-AS1 knockdown promoted the inhibitory impact of miR-765 on the expression of BCL2L13 and the apoptosis of N2a cells treated with OGD/R. Furthermore, we found that neurological deficits and brain injury induced by I/R in vivo were attenuated by FOXD3-AS1 knockdown.

CONCLUSIONS

We verified a critical signaling pathway of FOXD3-AS1/miR-765/BCL2L13 in regulating cerebral ischemia/reperfusion injury.

Dual Effects of Non-Coding RNAs (ncRNAs) in Cancer Stem Cell Biology

The identification of cancer stem cells (CSCs) as initiators of carcinogenesis has revolutionized the era of cancer research and our perception for the disease treatment options. Additional CSC features, including self-renewal and migratory and invasive capabilities, have further justified these cells as putative diagnostic, prognostic, and therapeutic targets. Given the CSC plasticity, the identification of CSC-related biomarkers has been a serious burden in CSC characterization and therapeutic targeting. Over the past decades, a compelling amount of evidence has demonstrated critical regulatory functions of non-coding RNAs (ncRNAs) on the exclusive features of CSCs. We now know that ncRNAs may interfere with signaling pathways, vital for CSC phenotype maintenance, such as Notch, Wnt, and Hedgehog. Here, we discuss the multifaceted contribution of microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), as representative ncRNA classes, in sustaining the CSC-like traits, as well as the underlying molecular mechanisms of their action in various CSC types. We further discuss the use of CSC-related ncRNAs as putative biomarkers of high diagnostic, prognostic, and therapeutic value.

Shrimp miR-965 induced the human melanoma stem-like cell apoptosis and inhibited their stemness by disrupting the MCL-1-ER stress-XBP1 feedback loop in a cross-species manner

BACKGROUND

Melanoma is a type of aggressive skin cancer with a poor survival rate. The resistance to conventional therapy of this disease is, at least in part, attributed to its cancer stem cell population. However, the mechanism of survival and stemness maintenance of cancer stem cells remains to be investigated.

METHODS

Tumorsphere formation assay was used to study the stem-like property of melanoma stem-like cells (MSLC). Chromatin immunoprecipitation (ChIP), promoter luciferase reporter assay were included for exploring the role of MCL-1 in MSLC and electrophoretic mobility shift assay were used to evaluate the interaction between shrimp miR-965 and human Ago2 protein. Melanoma xenograft nude mice were used to study the inhibition of tumor development.

RESULTS

In the present study, our results showed that myeloid cell leukemia sequence 1 (MCL-1) knocking down induced ER stress and apoptosis, and the expression reduction of stemness associated genes in MSLC, which implied a significant role of MCL-1 in MSLC. Further study indicated that ER stress agonist (tunicamycin) treatment in MSLC results in the translocation of XBP1, an ER stress sensor, into the nucleus to induce MCL-1 expression through direct binding to the - 313- to - 308-bp region of MCL-1 promoter. In addition, we found that a shrimp-derived miRNA (shrimp miR-965) could interact with the human Ago2 protein and suppressed the human MCL-1 expression by binding to the 3' UTR of MCL-1 mRNA, thereby inhibiting the MSLC proliferation and stemness in vitro and in vivo in a cross-species manner.

CONCLUSION

In conclusion, we identified an important role of MCL-1-ER stress-XBP1 feedback loop in the stemness and survival maintenance of MSLC, and shrimp miR-965, a natural food derived miRNA, could regulate MSLC stemness and survival by targeting MCL-1 and disrupting the balance of MCL-1-ER stress-XBP1 feedback loop. In conclusion, this study indicated an important mechanism of the regulation of MSLC stemness and survival, otherwise it also demonstrated the significance of cross-species-derived miRNA as promising natural drugs in melanoma therapy.

Identification of key microRNAs of plasma extracellular vesicles and their diagnostic and prognostic significance in melanoma

Melanoma is one of the most highly metastatic, aggressive and fatal malignant tumors in skin cancer. This study employs bioinformatics to identify key microRNAs and target genes (TGs) of plasma extracellular vesicles (pEVs) and their diagnostic and prognostic significance in melanoma. The gene expression microarray dataset (GSE100508) was downloaded from the Gene Expression Omnibus database. Differential analysis of miRNAs in pEVs was performed to compare melanoma samples and healthy samples. Then, TGs of the differential miRNAs (DE-miRNAs) in melanoma were selected, and differential genes were analyzed by bioinformatics (including Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment, protein–protein interaction network and prognostic analysis). A total of 55 DE-miRNAs were found, and 3,083 and 1,351 candidate TGs were diagnostically correlated with the top ten upregulated DE-miRNAs and all downregulated DE-miRNAs, respectively. Prognostic analysis results showed that high expression levels of hsa-miR-550a-3p, CDK2 and POLR2A and low expression levels of hsa-miR-150-5p in melanoma patients were associated with significantly reduced overall survival. In conclusion, bioinformatics analysis identified key miRNAs and TGs in pEVs of melanoma, which may represent potential biomarkers for the early diagnosis and treatment of this cancer.

GAS5, a FoxO1-actived long noncoding RNA, promotes propofol-induced oral squamous cell carcinoma apoptosis by regulating the miR-1297-GSK3β axis

Propofol, an intravenous anaesthetic agent, has been found to exhibit antitumour effects in various kinds of cancer cells. However, the potential roles and regulatory mechanisms of propofol in oral squamous cell carcinoma (OSCC) remain unknown. Herein, we found that propofol inhibits OSCC cell growth and promotes cell apoptosis in a dose- and time-dependent manner. Further mechanistic studies revealed that the long noncoding RNA GAS5 is induced by propofol in OSCC cells. Elevated GAS5 acts as a competing endogenous RNA for miR-1297 and attenuates its inhibitory effect on GSK3β, leading to GSK3β increase and Mcl1 decrease. Additionally, we found that FoxO1 binds to the promoter of GAS5, facilitating its transcription in response to propofol treatment. Thus, these results suggest that propofol exhibits antitumour effects in OSCC cells and that the FoxO1-GAS5-miR-1297-GSK3β axis plays an important role in propofol-induced OSCC cell apoptosis.

MiR-765 functions as a tumour suppressor and eliminates lipids in clear cell renal cell carcinoma by downregulating PLP2

Background

Lipid accumulation has been highlighted in cancer development and progression, but the exact mechanism remains unclear in renal cell carcinoma (RCC). MicroRNAs (miRNAs) have been confirmed to participate in the pathological processes of cancers, including tumour occurrence and inhibition. However, the role and mechanism of miR-765 have not been elucidated in clear cell renal cell carcinoma (ccRCC).

Methods

Using The Cancer Genome Atlas (TCGA) database and qRT-PCR, we investigated differences in miR-765 and proteolipid protein 2 (PLP2) expression, as well as their clinical relevance. To investigate the function of miR-765 and PLP2 in ccRCC, we performed in vitro and in vivo experiments to explore their biological functions in ccRCC.

Findings

In this study, we showed that miR-765 was upregulated in the plasma of ccRCC patients after tumour resection. Consistently, ccRCC tissues had low expression of miR-765 when compared with corresponding non-cancerous tissues. Overexpression of miR-765 suppressed cell proliferation and metastasis in vitro and in vivo. Mechanistic studies demonstrated that PLP2 was a direct target gene of miR-765. PLP2 was highly expressed in ccRCC tissues, and high PLP2 levels were positively correlated with higher tumour stage and grade and poor prognosis. PLP2 expression was negatively correlated with the miR-765 level in patient samples. We further showed that PLP2 restrained the cell metastasis and proliferation induced by miR-765 and reduced the lipid-eliminating effects of miR-765 in renal cancer cells.

Interpretation

Our findings suggest that miR-765 may function as a tumour suppressor and eliminate lipids in clear cell renal cell carcinoma by targeting PLP2.

Funding

This work was funded the grants from the National Natural Scientific Foundation of China (Grant No. 81672528, 81672524, 81602218, 31741032, 81902588).

Therapeutically targeting head and neck squamous cell carcinoma through synergistic inhibition of LSD1 and JMJD3 by TCP and GSK-J1

BACKGROUND

The histone demethylase LSD1 is a key mediator driving tumorigenesis, which holds potential as a promising therapeutic target. However, treatment with LSD1 inhibitors alone failed to result in complete cancer regression.

METHODS

The synergistic effects of TCP (a LSD1 inhibitor) and GSK-J1 (a JMJD3 inhibitor) against HNSCC were determined in vitro and in preclinical animal models. Genes modulated by chemical agents or siRNAs in HNSCC cells were identified by RNA-seq and further functionally interrogated by bioinformatics approach. Integrative siRNA-mediated gene knockdown, rescue experiment and ChIP-qPCR assays were utilised to characterise the mediators underlying the therapeutic effects conferred by TCP and GSK-J1.

RESULTS

Treatment with TCP and GSK-J1 impaired cell proliferation, induced apoptosis and senescence in vitro, which were largely recapitulated by simultaneous LSD1 and JMJD3 knockdown. Combinational treatment inhibited tumour growth and progression in vivo. Differentially expressed genes modulated by TCP and GSK-J1 were significantly enriched in cell proliferation, apoptosis and cancer-related pathways. SPP1 was identified as the mediator of synergy underlying the pro-apoptosis effects conferred by TCP and GSK-J1. Co-upregulation of LSD1 and JMJD3 associated with worse prognosis in patients with HNSCC.

CONCLUSIONS

Our findings revealed a novel therapeutic strategy of simultaneous LSD1 and JMJD3 inhibition against HNSCC.

HypoxamiRs Profiling Identify miR-765 as a Regulator of the Early Stages of Vasculogenic Mimicry in SKOV3 Ovarian Cancer Cells

Vasculogenic mimicry (VM) is a novel cancer hallmark in which malignant cells develop matrix-associated 3D tubular networks with a lumen under hypoxia to supply nutrients needed for tumor growth. Recent studies showed that microRNAs (miRNAs) may have a role in VM regulation. In this study, we examined the relevance of hypoxia-regulated miRNAs (hypoxamiRs) in the early stages of VM formation. Data showed that after 48 h hypoxia and 12 h incubation on matrigel SKOV3 ovarian cancer cells undergo the formation of matrix-associated intercellular connections referred hereafter as 3D channels-like structures, which arose previous to the apparition of canonical tubular structures representative of VM. Comprehensive profiling of 754 mature miRNAs at the onset of hypoxia-induced 3D channels-like structures showed that 11 hypoxamiRs were modulated (FC>1.5; p < 0.05) in SKOV3 cells (9 downregulated and 2 upregulated). Bioinformatic analysis of the set of regulated miRNAs showed that they might impact cellular pathways related with tumorigenesis. Moreover, overall survival analysis in a cohort of ovarian cancer patients (n = 485) indicated that low miR-765, miR-193b, miR-148a and high miR-138 levels were associated with worst patients outcome. In particular, miR-765 was severely downregulated after hypoxia (FC < 32.02; p < 0.05), and predicted to target a number of protein-encoding genes involved in angiogenesis and VM. Functional assays showed that ectopic restoration of miR-765 in SKOV3 cells resulted in a significant inhibition of hypoxia-induced 3D channels-like formation that was associated with a reduced number of branch points and patterned tubular-like structures. Mechanistic studies confirmed that miR-765 decreased the levels of VEGFA, AKT1 and SRC-α transducers and exerted a negative regulation of VEGFA by specific binding to its 3'UTR. Finally, overall survival analysis of a cohort of ovarian cancer patients (n = 1435) indicates that high levels of VEGFA, AKT1 and SRC-α and low miR-765 expression were associated with worst patients outcome. In conclusion, here we reported a novel hypoxamiRs signature which constitutes a molecular guide for further clinical and functional studies on the early stages of VM. Our data also suggested that miR-765 coordinates the formation of 3D channels-like structures through modulation of VEGFA/AKT1/SRC-α axis in SKOV3 ovarian cancer cells.

KLF4, a miR-32-5p targeted gene, promotes cisplatin-induced apoptosis by upregulating BIK expression in prostate cancer

BACKGROUND

Chemotherapeutic insensitivity remains a big challenge in prostate cancer treatment. Recently, increasing evidence has indicated that KLF4 plays a key role in prostate cancer. However, the potential biological role of KLF4 in Chemotherapeutic insensitivity of prostate cancer is still unknown.

METHODS

The role of KLF4 in cisplatin-induced apoptosis was detected by western blotting and a cell counting kit (CCK8). The potential molecular mechanism of KLF4 in regulating prostate cancer chemosensitivity was investigated by RNA sequencing analysis, q-RT-PCR, western blotting and chromatin immunoprecipitation (ChIP). The expression level of KLF4 mediated by miR-32-5p was confirmed by bioinformatic analysis and luciferase assays.

RESULTS

Here, we found that KLF4 was induced by cisplatin in prostate cancer cells and that the increase in KLF4 promoted cell apoptosis. Further mechanistic studies revealed that KLF4 directly bound to the promoter of BIK, facilitating its transcription. Additionally, we also found that the gene encoding KLF4 was a direct target of miR-32-5p. The downregulation of miR-32-5p in response to cisplatin treatment promoted KLF4 expression, which resulted in a increase in the chemosensitivity of prostate cancer.

CONCLUSION

Thus, our data revealed that KLF4 is an essential regulator in cisplatin-induced apoptosis, and the miR-32-5p-KLF4-BIK signalling axis plays an important role in prostate cancer chemosensitivity.

Regulation of the adaptation to ER stress by KLF4 facilitates melanoma cell metastasis via upregulating NUCB2 expression

BACKGROUND

Adaptation to ER stress has been indicated to play an important role in resistance to therapy in human melanoma. However, the relationship between adaptation to ER stress and cell metastasis in human melanoma remains unclear.

METHODS

The relationship of adaptation to ER stress and cell metastasis was investigated using transwell and mouse metastasis assays. The potential molecular mechanism of KLF4 in regulating the adaptation to ER stress and cell metastasis was investigated using RNA sequencing analysis, q-RT-PCR and western blot assays. The transcriptional regulation of nucleobindin 2 (NUCB2) by KLF4 was identified using bioinformatic analysis, luciferase assay, and chromatin immunoprecipitation (ChIP). The clinical significance of KLF4 and NUCB2 was based on human tissue microarray (TMA) analysis.

RESULTS

Here, we demonstrated that KLF4 was induced by ER stress in melanoma cells, and increased KLF4 inhibited cell apoptosis and promoted cell metastasis. Further mechanistic studies revealed that KLF4 directly bound to the promoter of NUCB2, facilitating its transcription. Additionally, an increase in KLF4 promoted melanoma ER stress resistance, tumour growth and cell metastasis by regulating NCUB2 expression in vitro and in vivo. Elevated KLF4 was found in human melanoma tissues, which was associated with NUCB2 expression.

CONCLUSION

Our data revealed that the promotion of ER stress resistance via the KLF4-NUCB2 axis is essential for melanoma cell metastasis, and KLF4 may be a promising specific target for melanoma therapy.