Silencing MARCH1 suppresses proliferation, migration and invasion of ovarian cancer SKOV3 cells via downregulation of NF-κB and Wnt/β-catenin pathways

Membrane-associated RING-CH 7 inhibits stem-like capacities of bladder cancer cells by interacting with nucleotide-binding oligomerization domain containing 1

BACKGROUND

Cancer stem-like capacities are major factors contributing to unfavorable prognosis. However, the associated molecular mechanisms underlying cancer stem-like cells (CSCs) maintain remain unclear. This study aimed to investigate the role of the ubiquitin E3 ligase membrane-associated RING-CH 7 (MARCH7) in bladder cancer cell CSCs.

METHODS

Male BALB/c nude mice aged 4-5 weeks were utilized to generate bladder xenograft model. The expression levels of MARCHs were checked in online databases and our collected bladder tumors by quantitative real-time PCR (q-PCR) and immunohistochemistry (IHC). Next, we evaluated the stem-like capacities of bladder cancer cells with knockdown or overexpression of MARCH7 by assessing their spheroid-forming ability and spheroid size. Additionally, we conducted proliferation, colony formation, and transwell assays to validate the effects of MARCH7 on bladder cancer CSCs. The detailed molecular mechanism of MARCH7/NOD1 was validated by immunoprecipitation, dual luciferase, and in vitro ubiquitination assays. Co-immunoprecipitation experiments revealed that nucleotide-binding oligomerization domain-containing 1 (NOD1) is a substrate of MARCH7.

RESULTS

We found that MARCH7 interacts with NOD1, leading to the ubiquitin-proteasome degradation of NOD1. Furthermore, our data suggest that NOD1 significantly enhances stem-like capacities such as proliferation and invasion abilities. The overexpressed MARCH7 counteracts the effects of NOD1 on bladder cancer CSCs in both in vivo and in vitro models.

CONCLUSION

Our findings indicate that MARCH7 functions as a tumor suppressor and inhibits the stem-like capacities of bladder tumor cells by promoting the ubiquitin-proteasome degradation of NOD1. Targeting the MARCH7/NOD1 pathway could be a promising therapeutic strategy for bladder cancer patients.

Exosome‑delivered miR‑486‑3p inhibits the progression of osteosarcoma via sponging CircKEAP1/MARCH1 axis components

Accumulating evidence shows that the disruption of competing endogenous RNA (ceRNA) networks plays a significant role in osteosarcoma (OS) initiation and progression. However, the specific roles and functions of the ceRNAs in OS remain unclear. First, differentially expressed microRNAs (DEMs) were identified by mining the E-MTAB-1136 and GSE28423 datasets. MiRWalk website was used to predict the target gene of miRNA. OS-associated circular RNA (circRNA) expression profiles were downloaded from the published microarray databases. Gene expression levels were assessed through reverse transcription-quantitative PCR and western blotting. The biological effects of circKEAP1, microRNA (miR)-486-3p and membrane-associated RINGCH finger protein 1 (MARCH1) in OS cells were investigated using Cell Counting Kit-8, Transwell, colony formation and wound healing assays. miR-486-3p was aberrantly downregulated in OS tissues and cell lines and was packed with exosomes. miR-486-3p overexpression was shown to inhibit OS cell progression and promoted cell cycle arrest in vitro. In addition, MARCH1 was identified as a direct downstream molecule of miR-486-3p in OS cells. circKEAP1 was found to be upregulated in OS tissues and cells. circKEAP1 was found to have binding sites with miR-486-3p. Mechanistically, circKEAP1 positively regulated MARCH1 expression by sponging miR-486-3p. Exosomal miR-486-3p inhibited the progression of OS by sponging the circKEAP1/MARCH1 axis. These findings may provide a promising treatment approach for OS.

Strategies to synergize PD-1/PD-L1 targeted cancer immunotherapies to enhance antitumor responses in ovarian cancer

Anti-programmed cell death 1/programmed cell death ligand 1 (anti-PD-1/PD-L1) antibodies have developed rapidly but exhibited modest activity in ovarian cancer (OC), achieving a clinical response rate ranging from 5.9% to 19%. Current evidence indicate that the establishment of an integrated cancer-immunity cycle is a prerequisite for anti-PD-1/PD-L1 antibodies. Any impairment in this cycle, including lack of cancer antigens release, impaired antigen-presenting, decreased T cell priming and activation, less T cells that are trafficked or infiltrated in tumor microenvironment (TME), and low tumor recognition and killings, will lead to decreased infiltrated cytotoxic T cells to tumor bed and treatment failure. Therefore, combinatorial strategies aiming to modify cancer-immunity cycle and reprogram tumor immune microenvironment are of great interest. By far, various strategies have been studied to enhance responsiveness to PD-1/PD-L1 inhibitors in OC. Platinum-based chemotherapy increases neoantigens release; poly (ADP-ribose) polymerase (PARP) inhibitors (PARPis) improve the function of antigen-presenting cells and promote the trafficking of T cells into tumors; epigenetic drugs help to complete the immune cycle by affecting multiple steps; immunotherapies like anti-cytotoxic T lymphocyte antigen 4 (CTLA-4) antibodies reactivate T cells, and other treatment strategies like radiotherapy helps to increase the expression of tumor antigens. In this review, we will summarize the preclinical studies by analyzing their contribution in modifying the cancer immunity cycle and remodeling tumor environment, and we will also summarize recent progress in clinical trials and discuss some perspectives to improve these treatment strategies.

Arsenic Trioxide inhibits Activation of Hedgehog Pathway in Human Neuroblastoma Cell Line SK-N-BE(2) Independent of Itraconazole

BACKGROUND

Neuroblastoma (NB) remains associated with a low overall survival rate over the long term. Abnormal activation of the Hedgehog (HH) signaling pathway can activate the transcription of various downstream target genes that promote NB. Both arsenic trioxide (ATO) and itraconazole (ITRA) can inhibit tumor growth.

OBJECTIVE

To determine whether ATO combined with ITRA can be used to treat NB with HH pathway activation, we examined the effects of ATO and ITRA monotherapy or combined inhibition of the HH pathway in NB.

METHODS

Analysis of CCK8 and flow cytometry showed cell inhibition and cell cycle, respectively. Real-time PCR analysis was conducted to assess the mRNA expression of HH pathway.

RESULTS

We revealed that as concentrations of ATO and ITRA increased, the killing effects of both agents on SK-N-BE(2) cells became more apparent. During G2/M, the cell cycle was largely arrested by ATO alone and combined with ITRA, and in the G0/G1 phase by ITRA alone. In the HH pathway, ATO inhibited the transcription of the SHH, PTCH1, SMO and GLI2 genes, however, ITRA did not. Instead of showing synergistic effects in a combined mode, ITRA decreased ATO inhibitory effects.

CONCLUSION

We showed that ATO is an important inhibitor of HH pathway but ITRA can weaken the inhibitory effect of ATO. This study provides an experimental evidence for the clinical use of ATO and ITRA in the treatment of NB with HH pathway activation in cytology.

Association of MARCH7 with tumor progression and T-cell infiltration in esophageal cancer

MARCH7 is an E3 ubiquitin ligase known to regulate neuronal development,T-cell proliferation, and cell and tissue differentiation. But, the altered expression of MARCH7 has been observed in various malignancies. Herein, the cellular localization and role of MARCH7 have been elucidated in esophageal squamous cell carcinoma (ESCC), the information regarding which is currently limited. To check the expression of MARCH7 and its correlation with immune cells infiltration in ESCC, immunohistochemical analysis was performed. RNAi approach was used to investigate the role of MARCH7 in esophageal cancer cells. Interestingly, we found a significantly higher expression of MARCH7 protein in 84% of ESCC tissues than in distant matched non-malignant tissues (p ≤ 0.001). In addition to this, immunohistochemistry results have shown a negative correlation between MARCH7 protein expression and tumor-infiltrating immune cells such as CD8 + T cells (r = - 0.633, p = 0.001) and PD1 + T cells (r = - 0.560, p = 0.005). Furthermore, MARCH7 silencing inhibited the ESCC cell growth and reduced the clonogenic and invasion/migration potential of ESCC cells. MARCH7 silencing also significantly increased E-cadherin protein levels in ESCC cells relative to those in negative control cells (p < 0.05). Thus, MARCH7 is oncogenic and might have a possible role in esophageal carcinogenesis. Moreover, E-cadherin may be a downstream target of MARCH7 in ESCC.

MARCH1 as a novel immune-related prognostic biomarker that shapes an inflamed tumor microenvironment in lung adenocarcinoma

E3 ubiquitin ligases (E3s), the second most common cancer-related functional protein family, play vital roles in multiple tumors. However, their importance in prognosis and immunotherapy of lung adenocarcinoma (LUAD) is not clear. First, utilizing the data from The Cancer Genome Atlas (TCGA), we comprehensively assessed the expression profile and immunological association of 13 E3s in LUAD patients. Consequently, MARCH1 was considered a candidate for further study. Second, several algorithms were applied to assess the correlation between MARCH1 and immunological characteristics in the LUAD tumor microenvironment. Third, an immune risk score (IRS) was developed to predict the prognosis. Finally, the immunological relationship of MARCH1 in pan-cancer was also estimated. We found that E3s were disordered in LUAD. Among them, MARCH1 was positively correlated with most immunological characteristics, indicating that MARCH1 designed an inflamed TME in LUAD. Coincidently, LUAD with low MARCH1 expression had a poor prognosis and was not sensitive to immune checkpoint blockers. In addition, the IRS could accurately predict the prognosis. In pan-cancer, MARCH1 was also positively correlated with most immunological characteristics. In conclusion, MARCH1 could be a novel and promising biomarker for immune status and effectiveness of immunotherapy for LUAD patients.

The role of MARCH9 in colorectal cancer progression

Colorectal cancer (CRC) is the third most common cancer with a high global incidence and mortality. Mutated genes or dysregulated pathways responsible for CRC progression have been identified and employed as biomarkers for diagnosis and prognosis. In this study, a ubiquitination regulator, MARCH9, was shown to accelerate CRC progression both in vitro and in vivo. CRC samples from The Cancer Genome Atlas (TCGA) showed significantly upregulated MARCH9 expression by individual cancer stage, histological subtype, and nodal metastasis status. Knockdown of MARCH9 inhibited, while MARCH9 overexpression promoted, CRC cell proliferation and migration. Knockdown of MARCH9 also induced CRC cell apoptosis and caused cell cycle arrest. Further investigation showed that MARCH9 promoted CRC progression by downregulating the expression of a deubiquitinase cylindromatosis (CYLD) gene and activating p65, a member of the nuclear factor-κB (NF-κB) protein family. Finally, in vivo xenograft studies confirmed that MARCH9 knockdown suppressed tumor growth in nude mice. Thus, this study demonstrated that MARCH9 may be a novel and effective therapeutic target for CRC therapy.

MARCH1 silencing suppresses growth of oral squamous cell carcinoma through regulation of PHLPP2

PURPOSE

Oral squamous cell carcinoma (OSCC) is the most frequent type of oral cancer and is associated with high mortality. Membrane-associated ring-CH type finger 1 (MARCH1) is an E3 ubiquitin ligase with roles in immune regulation and cancer development. Whether MARCH1 has a specific role in OSCC, and if so through what mechanism, has not been explored.

METHODS

Immunohistochemistry was performed to examine MARCH1 expression in OSCC clinical samples and adjacent paracancerous tissues. Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and Western blot were conducted to determine mRNA expression and protein levels, respectively. Knockdown and overexpression experiments were carried out to evaluate the effects of MARCH1 on proliferation and apoptosis. To test protein-protein interaction, co-immunoprecipitation assay was performed. Finally, tumor cell grafting was utilized to test the function of MARCH in vivo.

RESULTS

High MARCH1 expression in OSCC clinical samples correlated with poor patient prognosis. Functionally, MARCH1 knockdown in OSCC cells suppressed proliferation and promoted apoptosis, while MARCH1 overexpression displayed the opposite effects. We identified PH Domain And Leucine Rich Repeat Protein Phosphatase (PHLPP) 2 as an important target of MARCH1. Mechanistically, MARCH1 interacted with PHLPP2 and promoted PHLPP2 ubiquitination. Lastly, MARCH1 knockdown suppressed OSCC tumorigenicity in vivo and increased PHLPP2 protein level.

CONCLUSION

Our study uncovered a function of MARCH1 in OSCC and identified PHLPP2 as an important target of MARCH1 to modulate OSCC cell proliferation and apoptosis.

The emerging role of miR-653 in human cancer

MicroRNAs (miRNAs) refer to a family of non-coding RNA with ~22 nucleotides in length. A high number of studies show evidence that deregulation in miRNAs expression could be implicated in the processes of many pathologies such as cancer, hypoxia, and stroke. Herein, we aimed to summarize the miR-653 expression level and molecular mechanisms through which it functions in human cancer. It was found that variations in miR-653 expression are linked to tumor aggressiveness and unfavorable prognosis in human cancer, and it plays an inhibitory effect in some types of cancer, such as breast, cervical, liver, renal, and lung cancers. In contrast, it plays an acceleratory impact in some other cancers, such as bladder and prostate cancers. In gastric cancer, the role played by miR-653 is still controversial and will need to be elucidated in future studies. Future studies could definitely establish targeting miR-653 as a novel strategy in human cancer, from diagnosis to effective treatment.

March1-overexpressed dendritic cells downregulate Th1/Th2 ratio in asthma through promoting OX40L

Asthma is an inflammatory disease. Th2 differentiation plays an important role in the pathogenesis of asthma. We explored the role and action mechanism of membrane-associated RING-CH 1 (March1) in the Th2 differentiation regulated by dendritic cells (DCs). Our data showed that the expression of March1 was higher in asthmatic children-derived DCs, asthmatic mice-derived DCs and house dust mites (HDMs)-treated DCs than that in control DCs. Increasing of March1 promoted the production of pro-inflammatory cytokines from HDMs-treated DCs, and enhanced the promotion of HDMs-treated DCs to CD4⁺T cell proliferation and Th2 differentiation, whereas decreasing of March1 resulted in opposite effects. Furthermore, our data indicated that March1 positively regulated the expression of OX40 ligand (OX40L) and facilitated DCs-induced Th2 differentiation through OX40L. In asthmatic mice, March1-overexpressed DCs significantly aggravated the injury in lung tissues and promoted Th2 differentiation. Overall, our data proved that highly expressed March1 in DCs facilitated asthma development through inducing Th2 differentiation by facilitating OX40L expression. Our data might provide a new idea for the treatment of asthma.

Myricetin Induces Autophagy and Cell Cycle Arrest of HCC by Inhibiting MARCH1-Regulated Stat3 and p38 MAPK Signaling Pathways

Myricetin is a type of natural flavonol known for its anticancer activity. However, the molecular mechanism of myricetin in anti-hepatocellular carcinoma (HCC) is not well defined. Previous studies indicated that downregulation of membrane-associated RING-CH finger protein 1 (MARCH1) contributed to the treatment of a variety of cancers. Whether the anticancer property of myricetin is associated with MARCH1 expression remains to be investigated. This research explored the anti-HCC mechanism of myricetin. Our results indicate that myricetin induces autophagy and arrests cell cycle at the G2/M phase to suppress the proliferation of HCC cells by downregulating MARCH1. Myricetin reduces MARCH1 protein in Hep3B and HepG2 cells. Interestingly, myricetin upregulates the MARCH1 mRNA level in Hep3B cells but downregulates it in HepG2 cells. The knockdown of MARCH1 by siRNAs (small interfering RNAs) decreases the phosphorylated p38 MAPK (p-p38 MAPK) and Stat3 (p-Stat3), and inhibits HCC cell viability. Moreover, myricetin inhibits p38 MAPK and Stat3 signaling pathways by downregulating MARCH1 to repress HCC growth both in vitro and in vivo. Bafilomycin A1 (BafA1), an autophagy inhibitor, has synergetic effect with myricetin to inhibit HCC growth. Taken together, our results reveal that myricetin inhibits the proliferation of HCC cells by inhibiting MARCH1-regulated p38 MAPK and Stat3 signaling pathways. This research provides a new molecular mechanism for myricetin in anti-HCC and suggests that targeting MARCH1 could be a novel treatment strategy in developing anticancer therapeutics.

Sinomenine Suppresses Development of Hepatocellular Carcinoma Cells via Inhibiting MARCH1 and AMPK/STAT3 Signaling Pathway

Promotion of apoptosis and suppression of proliferation in tumor cells are popular strategies for developing anticancer drugs. Sinomenine (SIN), a plant-derived alkaloid, displays antitumor activity. However, the mechanism of action of SIN against hepatocellular carcinoma (HCC) is unclear. Herein, several molecular technologies, such as Western Blotting, qRT-PCR, flow cytometry, and gene knockdown were applied to explore the role and mechanism of action of SIN in the treatment of HCC. It was found that SIN arrests HCC cell cycle at G0/G1 phase, induces apoptosis, and suppresses proliferation of HCC cells via down-regulating the expression of membrane-associated RING-CH finger protein 1 (MARCH1). Moreover, SIN induces cell death and growth inhibition through AMPK/STAT3 signaling pathway. MARCH1 expression was silenced by siRNA to explore its involvement in the regulation of AMPK/STAT3 signaling pathway. Silencing MARCH1 caused down-regulation of phosphorylation of AMPK, STAT3 and decreased cell viability and function. Our results suggested that SIN inhibits proliferation and promotes apoptosis of HCC cells by MARCH1-mediated AMPK/STAT3 signaling pathway. This study provides new support for SIN as a clinical anticancer drug and illustrates that targeting MARCH1 could be a novel treatment strategy in developing anticancer therapeutics.

iTRAQ-based analysis for the identification of MARCH8 targets in human esophageal squamous cell carcinoma

MARCH8 is an E3 ligase, primarily involved in immune-modulation. Recently, we reported its aberrant expression in human esophageal squamous cell carcinoma. However, exact mechanisms by which it regulates cancer have been poorly understood. We applied high-throughput quantitative proteomics approach to identify downstream protein targets of MARCH8. Silencing of endogenous MARCH8 in ESCC cells followed by LC-MS/MS analysis led to identification of 1,029 unique proteins showing altered expression post MARCH8 knockdown. Several previously reported MARCH8 target proteins viz. TFR1, syntaxin-4, e-cadherin and CD44 were found to be upregulated. Furthermore, new putative targets of MARCH8, including β2M, were identified in the present study. We demonstrated that MARCH8 interacts with and ubiquitinates CDH1 and β2M. Inhibiting proteasome activity with MG132 prevented CDH1 and β2M degradation, indicating that MARCH8 might be targeting CDH1 and β2M for proteasomal degradation. Further, loss of β2M and CDH1 expression significantly and inversely correlated with MARCH8 expression in ESCC tissues (r =  -0.737 and  - 0.651, respectively; p < 0.01). In conclusion, our present study has led to identification of new targets of MARCH8 and suggests the role of MARCH8 in regulating CDH1 and β2M turnover in esophageal cancer cells. SIGNIFICANCE: The use of quantitative proteomics carried out has led to the recognition of new targets of MARCH8. The present study gives a broad understanding of the molecular remodeling arising in the ESCC after MARCH8 knockdown. The study also solidifies the idea that role of MARCH8 is not just limited to immunomodulation as silencing of MARCH8 affects various other processes such as protein processing and localization. This study might help in understanding the regulation of MARCH8 in ESCCs and the mechanism by which MARCH8 might be facilitating cancer cells to evade immune surveillance.

The emerging roles of the MARCH ligases in antiviral innate immunity

Membrane-associated RING (really interesting new gene)-cysteine-histidine (CH) (MARCH) ubiquitin ligases belong to a RING finger domain E3 ligases family. So far, eleven members have been found in the MARCH family, which are MARCH 1 to 11. The members of the MARCH family are widely distributed and involve in a variety of cellular functions, including regulation of the immune system, transmembrane transport of proteins, protein stability, endoplasmic reticulum-related degradation, and endosome protein transport. Several seminal studies over the past decade have delineated that MARCH affects viral replication through various mechanisms by regulating the activity of signaling molecules and their expression in the antiviral innate immune responses. Here, we summarize the complex roles of MARCH ligases in the antiviral innate immune signaling pathway and its impact on viral replication in host immune defense systems. A better understanding of this interplay's molecular mechanisms is important concerning the development of new therapeutics targeting viral infections.

Osteoglycin silencing exerts inhibitory effects on myocardial fibrosis and epithelial/endothelial-mesenchymal transformation in a mouse model of myocarditis

Osteoglycin (Ogn), a class III SLRP member with multiple glycosylation sites, has been proposed to be engaged in cardiac dysfunction and adverse remodeling in human heart failure following myocardial infarction. However, the underlying mechanism remains to be elucidated. Thus, we sought to define the role of Ogn in regulation of the Wnt pathway on myocardial fibrosis and epithelial/endothelial-mesenchymal transformation (EMT/EndMT) in mice with myocarditis. The pathological changes are observed, while hematoxylin-eosin staining and picric acid Sirius red staining were conducted in successfully constructed myocarditis mouse models. Immunohistochemistry and enzyme-linked immunosorbent assay were adopted to determine Ogn and β-catenin levels and serum procollagen propeptide concentrations in the mouse myocardial tissues, respectively. Expression of Ogn and Wnt signaling pathway-related factors were measured by reverse transcription quantitative polymerase chain reaction and western blot assay, cell viability by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and cell cycle distribution and apoptosis by flow cytometry. We saw indicative pathological changes accompanied by many Ogn and β-catenin positive cells and increased serum procollagen propeptide, in the mouse myocardial tissues. Loss function assays showed reduced levels of Ogn, β-catenin, LRP6, TGF-β1, Twist, FSP-1, α-SMA and higher levels of E-cadherin and VE-cadherin, together with decreased proliferation rate, as well as increased apoptosis rate, indicating that the Wnt signaling pathway, proliferation were inhibited while apoptosis was enhanced with upon gene silencing. Coherently, depletion of Ogn inhibits myocardial fibroblasts proliferation and EMT/EndMT while facilitating myocardial fibroblasts apoptosis in myocarditis through the Wnt signaling pathway, thus serving as an intervention target for the molecular treatment of myocarditis.

5-FU inhibits migration and invasion of CRC cells through PI3K/AKT pathway regulated by MARCH1

Colorectal cancer is a major health problem with a significant impact on the patients' quality of life. 5‐Fluorouracil is the most common chemotherapy drug used for this type of cancer. While its molecular mechanism is the inhibition of DNA synthesis via the inhibition of thymine nucleotide synthetase, its complete anticancer mechanism is not clear. Membrane‐associated RING‐CH‐1 (MARCH1) is an E3 ubiquitin ligase that plays an important role in antigen presentation. However, MARCH1 has not been studied in the context of colorectal cancer. In this study, we demonstrated that MARCH1 is highly expressed in colorectal cancer tissues and cell lines. Furthermore, migration and invasion of colorectal tumor cells were inhibited via transfection with small interfering RNAs to suppress the expression of MARCH1. The western blot analysis showed that MARCH1 regulates epithelial–mesenchymal transition and the PI3K/AKT pathway. Moreover, 5‐fluorouracil inhibited the proliferation, migration, and invasion of tumor cells, via the targeting of MARCH1 and the consequent downregulation of the PI3K/AKT pathway, impacting the progression of epithelial–mesenchymal transition. In conclusion, our study shows that MARCH1 may play a role as an oncogene in colorectal cancer and may represent a new target molecule of 5‐fluorouracil.

Uncovering Prognosis-Related Genes and Pathways by Multi-Omics Analysis in Lung Cancer

Lung cancer is one of the leading causes of death worldwide. Therefore, understanding the factors linked to patient survival is essential. Recently, multi-omics analysis has emerged, allowing for patient groups to be classified according to prognosis and at a more individual level, to support the use of precision medicine. Here, we combined RNA expression and miRNA expression with clinical information, to conduct a multi-omics analysis, using publicly available datasets (the cancer genome atlas (TCGA) focusing on lung adenocarcinoma (LUAD)). We were able to successfully subclass patients according to survival. The classifiers we developed, using inferred labels obtained from patient subtypes showed that a support vector machine (SVM), gave the best classification results, with an accuracy of 0.82 with the test dataset. Using these subtypes, we ranked genes based on RNA expression levels. The top 25 genes were investigated, to elucidate the mechanisms that underlie patient prognosis. Bioinformatics analyses showed that the expression levels of six out of 25 genes (ERO1B, DPY19L1, NCAM1, RET, MARCH1, and SLC7A8) were associated with LUAD patient survival (p < 0.05), and pathway analyses indicated that major cancer signaling was altered in the subtypes.

P-MAPA and Interleukin-12 Reduce Cell Migration/Invasion and Attenuate the Toll-Like Receptor-Mediated Inflammatory Response in Ovarian Cancer SKOV-3 Cells: A Preliminary Study

Immunotherapies have emerged as promising complementary treatments for ovarian cancer (OC), but its effective and direct role on OC cells is unclear. This study examined the combinatory effects of the protein aggregate magnesium-ammonium phospholinoleate-palmitoleate anhydride, known as P-MAPA, and the human recombinant interleukin-12 (hrIL-12) on cell migration/invasion, apoptosis, toll-like receptor (TLR)-mediated inflammation, and cytokine/chemokine profile in human OC cell line SKOV-3. P-MAPA and IL-12 showed cancer cell toxicity under low doses after 48 h. Although apoptosis/necrosis and the cell cycle were unchanged by the treatments, P-MAPA enhanced the sensitivity to paclitaxel (PTX) and P-MAPA associated with IL-12 significantly reduced the migratory potential and invasion capacity of SKOV-3 cells. P-MAPA therapy reduced TLR2 immunostaining and the myeloid differentiation factor 88 (MyD88), but not the TLR4 levels. Moreover, the combination of P-MAPA with IL-12 attenuated the levels of MyD88, interferon regulatory factor 3 (IRF3) and nuclear factor kappa B (NF-kB p65). The IL-12 levels were increased and P-MAPA stimulated the secretion of cytokines IL-3, IL-9, IL-10, and chemokines MDC/CCL22 and, regulated on activation, normal T cells expressed and secreted (RANTES)/CCL5. Conversely, combination therapy reduced the levels of IL-3, IL-9, IL-10, MDC/CCL22, and RANTES/CCL5. Collectively, P-MAPA and IL-12 reduce cell dynamics and effectively target the TLR-related downstream molecules, eliciting a protective effect against chemoresistance. P-MAPA also stimulates the secretion of anti-inflammatory molecules, possibly having an immune response in the OC microenvironment.

ciRs-6 upregulates March1 to suppress bladder cancer growth by sponging miR-653

BACKGROUND

Circular RNAs have been widely explored as potential biomarkers and therapeutic targets in bladder cancer; however, few have been functionally characterized.

RESULTS

ciRs-6 is expressed at low levels in cancer tissues and advanced tumor grades and stages, and its expression correlates with better outcomes for bladder cancer patients. In vitro and in vivo, ciRs-6 was shown to suppress bladder cancer growth by sponging miR-653 to elevate March1 levels. March1 is an E3 ubiquitin ligase that has been proven to suppress bladder cancer growth; knocking down March1 in ciRs-6 overexpressed bladder cancer cells reversed the tumor suppressive effect of ciRs-6.

CONCLUSIONS

Our study identifies an oncogenic role of ciRs-6 and suggests its usefulness as a novel biomarker for bladder cancer diagnosis and prognosis and as a therapeutic target for bladder cancer.

METHODS

ciRs-6 was identified by RNA-seq and qPCR; CCK8 assays, clone forming assays and cell cycle analyses were performed to evaluate the in vitro effect of ciRs-6 in bladder cancer; further, a mouse subcutaneous tumor model was designed for in vivo analysis. RNA pulldown assays, miRNA capture experiments and dual luciferase assessments were applied for mechanistic studies.

The Membrane-Associated MARCH E3 Ligase Family: Emerging Roles in Immune Regulation

The membrane-associated RING-CH-type finger (MARCH) proteins of E3 ubiquitin ligases have emerged as critical regulators of immune responses. MARCH proteins target immune receptors, viral proteins as well as components in innate immune response for polyubiquitination and degradations via distinct routes. This review summarizes the current progress about MARCH proteins and their regulation on immune responses.

NK Response Correlates with HIV Decrease in Pegylated IFN-α2a-Treated Antiretroviral Therapy-Suppressed Subjects

We previously reported that pegylated IFN-α2a (Peg-IFN-α2a) added to antiretroviral therapy (ART)-suppressed, HIV-infected subjects resulted in plasma HIV control and integrated HIV DNA decrease. We now evaluated whether innate NK cell activity or PBMC transcriptional profiles were associated with decreases in HIV measures. Human peripheral blood was analyzed prior to Peg-IFN-α2a administration (ART, baseline), after 5 wk of ART+Peg-IFN-α2a, and after 12 wk of Peg-IFN-α2a monotherapy (primary endpoint). After 5 wk of ART+Peg-IFN-α2a, immune subset frequencies were preserved, and induction of IFN-stimulated genes was noted in all subjects except for a subset in which the lack of IFN-stimulated gene induction was associated with increased expression of microRNAs. Viral control during Peg-IFN-α2a monotherapy was associated with 1) higher levels of NK cell activity and IFN-γ-induced protein 10 (IP-10) on ART (preimmunotherapy) and 2) downmodulation of NK cell KIR2DL1 and KIR2DL2/DL3 expression, transcriptional enrichment of expression of genes associated with NK cells in HIV controller subjects, and higher ex vivo IFN-α-induced NK cytotoxicity after 5 wk of ART+Peg-IFN-α2a. Integrated HIV DNA decline after immunotherapy was also associated with gene expression patterns indicative of cell-mediated activation and NK cytotoxicity. Overall, an increase in innate activity and NK cell cytotoxicity were identified as correlates of Peg-IFN-α2a-mediated HIV control.

FAM83D inhibits autophagy and promotes proliferation and invasion of ovarian cancer cells via PI3K/AKT/mTOR pathway

Ovarian cancer is one of the most lethal malignant tumors in women. The family with sequence similarity 83, member D (FAM83D) plays an important role in several cancers, but its function and underlying mechanism in ovarian cancer remain unknown. To investigate the role of FAM83D in ovarian cancer, the expression of FAM83D was determined by immunohistochemistry in tissue microarray slide. Cellular proliferation and invasion were detected by 5-Ethynyl-2'-deoxyuridine assays and transwell invasion assays. The correlations between FAM83D and autophagy were detected by western blot analysis and confocal microscopy. Western blot analysis was used to identify the protein expression of FAM83D, phosphoinositide 3-kinase (PI3K), protein kinase B (AKT), mammalian target of rapamycin (mTOR) and Sequestosome 1 (P62). Tumorigenesis in nude mice was used to explore the function of FAM83D in vivo. We found high expression level of FAM83D in ovarian cancer tissues as compared to the normal ovarian tissues. Knockdown of FAM83D in SKOV3 cells enhanced autophagy and inhibited the proliferation and invasion in vitro, whereas ectopic expression of FAM83D in A2780 cells exerted an opposite effect. Mechanistically, overexpression of FAM83D activated the PI3K/AKT/mTOR pathway, and Torin1 could suppress FAM83D-induced cell proliferation and invasion. In vivo, overexpression FAM83D promoted tumor growth. Overall, FAM83D promoted ovarian cancer cell invasion and proliferation, while inhibited autophagy via the PI3K/AKT/mTOR signaling pathway. Our results suggest that FAM83D may be a candidate oncogene in ovarian cancer, which provides a fresh perspective of FAM83D in ovarian cancer.

MARCH1 encourages tumour progression of hepatocellular carcinoma via regulation of PI3K-AKT-β-catenin pathways

Membrane‐associated RING‐CH‐1 (MARCH1) is a membrane‐anchored E3 ubiquitin ligase that is involved in a variety of cellular processes. MARCH1 was aberrantly expressed as a tumour promoter in ovarian cancer, but the signalling about the molecular mechanism has not yet been fully illuminated. Here, we first determined that MARCH1 was obviously highly expressed in human hepatocellular carcinoma samples and cells. In addition, our findings demonstrated that the proliferation, migration and invasion of hepatocellular carcinoma were suppressed, but the apoptosis was increased, as a result of MARCH1 knockdown by either siRNA targeting MARCH1 or pirarubicin treatment. Conversely, the proliferation, migration and invasion of hepatocellular carcinoma were obviously accelerated, and the apoptosis was decreased, by transfecting the MARCH1 plasmid to make MARCH1 overexpressed. Moreover, in vivo, the results exhibited a significant inhibition of the growth of hepatocellular carcinoma in nude mice, which were given an intra‐tumour injection of siRNA targeting MARCH1. Furthermore, our study concluded that MARCH1 functions as a tumour promoter, and its role was up‐regulated the PI3K‐AKT‐β‐catenin pathways both in vitro and in vivo. In summary, our work determined that MARCH1 has an important role in the development and progression of hepatocellular carcinoma and may be used as a novel potential molecular therapeutic target in the future treatment of hepatocellular carcinoma.

Secalonic Acid-F, a Novel Mycotoxin, Represses the Progression of Hepatocellular Carcinoma via MARCH1 Regulation of the PI3K/AKT/β-catenin Signaling Pathway

Liver cancer is a very common and significant health problem. Therefore, powerful molecular targeting agents are urgently needed. Previously, we demonstrated that secalonic acid-F (SAF) suppresses the growth of hepatocellular carcinoma (HCC) cells (HepG2), but the other anticancer biological functions and the underlying mechanism of SAF on HCC are unknown. In this study, we found that SAF, which was isolated from a fungal strain in our lab identified as Aspergillus aculeatus, could inhibit the progression of hepatocellular carcinoma by targeting MARCH1, which regulates the PI3K/AKT/β-catenin and antiapoptotic Mcl-1/Bcl-2 signaling cascades. First, we confirmed that SAF reduced the proliferation and colony formation of HCC cell lines (HepG2 and Hep3B), promoted cell apoptosis, and inhibited the cell cycle in HepG2 and Hep3B cells in a dose-dependent manner. In addition, the migration and invasion of HepG2 and Hep3B cells treated with SAF were significantly suppressed. Western blot analysis showed that the level of MARCH1 was downregulated by pretreatment with SAF through the regulation of the PI3K/AKT/β-catenin signaling pathways. Moreover, knockdown of MARCH1 by small interfering RNAs (siRNAs) targeting MARCH1 also suppressed the proliferation, colony formation, migration, and invasion as well as increased the apoptotic rate of HepG2 and Hep3B cells. These data confirmed that the downregulation of MARCH1 could inhibit the progression of hepatocellular carcinoma and that the mechanism may be via PI3K/AKT/β-catenin inactivation as well as the downregulation of the antiapoptotic Mcl-1/Bcl-2. In vivo, the downregulation of MARCH1 by treatment with SAF markedly inhibited tumor growth, suggesting that SAF partly blocks MARCH1 and further regulates the PI3K/AKT/β-catenin and antiapoptosis Mcl-1/Bcl-2 signaling cascade in the HCC nude mouse model. Additionally, the apparent diffusion coefficient (ADC) values, derived from magnetic resonance imaging (MRI), were increased in tumors after SAF treatment in a mouse model. Taken together, our findings suggest that MARCH1 is a potential molecular target for HCC treatment and that SAF is a promising agent targeting MARCH1 to treat liver cancer patients.

Silencing the expression of MTDH increases the radiation sensitivity of SKOV3 ovarian cancer cells and reduces their proliferation and metastasis

Ovarian cancer has a high mortality rate among women worldwide. Radiotherapy is considered an effective method of ovarian cancer treatment, however, radioresistance presents a challenge. It is necessary to develop techniques that can increase radiosensitivity in ovarian cancer, and gene therapy is a promising option. The aim of the present study was to investigate the effects of metadherin (MTDH) silencing on the radiosensitivity of ovarian cancer. Ovarian cancer tissues (n=273) and normal ovarian tissues (n=277) were used, as were SKOV3 ovarian cancer cells and the immortalized human ovarian epidermal HOSEpiC cell line. MTT, Transwell and wound-healing assays were performed to assess the proliferation, invasion and migration abilities of the SKOV3 cells. Colony-forming assays and flow cytometry were applied to detect the radiosensitivity and apoptosis of the SKOV3 cells. Nude mouse xenograft models were established to evaluate the effect of MTDH gene silencing on tumor growth and the efficacy of radiotherapy. Ovarian cancer, in tissues and cells, was demonstrated to have a high level of MTDH. Additionally, MTDH silencing was found to significantly inhibit proliferation, migration and invasion, and induce apoptosis in SKOV3 cells, and it was suggested that MTDH depletion significantly increased the sensitivity of the SKOV3 cells to X-ray radiation. MTDH silencing enhanced radiosensitivity and delayed tumor growth in the nude mouse xenograft model. Collectively, the results obtained in the present study suggest the potential role of MTDH silencing as a technique for ameliorating radioresistance in ovarian cancer. The present study provides a promising experimental basis for the improvement of ovarian cancer radiotherapy treatment.

Long non-coding RNA LSINCT5 promotes ovarian cancer cell proliferation, migration and invasion by disrupting the CXCL12/CXCR4 signalling axis

Long stress-induced noncoding transcript 5 (LSINCT5) is a member of the LSINCT family, members of which are expressed during stress-induced cell formation and have also been reported to promote cancer progression. In the present study, the association between LSINCT5 expression and clinical significance was investigated and the biological function of LSINCT5 in epithelial ovarian cancer (EOC) was explored. LSINCT5 expression was examined in EOC tissues by reverse transcription-quantitative polymerase chain reaction and its association with clinicopathological factors was analysed. Cell proliferation, migration and invasion tests were performed to observe the role of LSINCT5 in human ovarian cancer cell lines in vitro. The negative control (NC) and siLSINCT5 SKOV3 cells were treated with chemokine ligand 12 (CXCL12) and their proliferation, migration and invasion activities were examined. LSINCT5 was overexpressed in EOC compared with normal ovarian tissue. LSINCT5 expression was significantly associated with the International Federation of Gynecologists and Obstetricians cancer stage and the presence of lymphatic metastases. Silencing LSINCT5 significantly reduced the expression of chemokine receptor 4 (CXCR4) and inhibited SKOV3 cell proliferation, migration and invasion, however the CXCL12 expression level had no significant change. When NC and siLSINCT5-SKOV3 cells were treated with CXCL12, the proliferation and invasion ability were significantly enhanced. The migration ability of the siLSINCT5-SKOV3 cells was also significantly enhanced. The present study indicated that LSINCT5 serves an important role in ovarian cancer metastasis by regulating the CXCL12/CXCR4 signalling axis, suggesting that this pathway may be a potential target for the treatment of patients with EOC.

Chrysophanol inhibits proliferation and induces apoptosis through NF-κB/cyclin D1 and NF-κB/Bcl-2 signaling cascade in breast cancer cell lines

Chrysophanol is an anthraquinone compound, which exhibits anticancer effects on certain types of cancer cells. However, the effects of chrysophanol on human breast cancer remain to be elucidated. The aim of the present study was to clarify the role of chrysophanol on breast cancer cell lines MCF-7 and MDA-MB-231, and to identify the signal transduction pathways regulated by chrysophanol. MTT assay and flow cytometric analysis demonstrated that chrysophanol inhibited cell proliferation, and cell cycle progression in a dose-dependent manner. The expression of cell cycle-associated cyclin D1 and cyclin E were downregulated while p27 expression was upregulated following chrysophanol treatment at the mRNA, and protein levels. The Annexin V/propidium iodide staining assay results revealed that apoptosis levels increased following chrysophanol treatment. Chrysophanol upregulated caspase 3 and poly (ADP-ribose) polymerase cleavage in both cell lines. Furthermore, chrysophanol enhanced the effect of paclitaxel on breast cancer cell apoptosis. In addition, chrysophanol downregulated apoptosis regulator Bcl-2 protein, and transcription factor p65 and IκB phosphorylation. Inhbition of nuclear factor (NF)-κB by ammonium pyrrolidine dithiocarbamate diminished the effect of chrysophanol on apoptosis and associated proteins. In conclusion, the results of the current study demonstrated that chrysophanol effectively suppresses breast cancer cell proliferation and facilitates chemosentivity through modulation of the NF-κB signaling pathway.

Increased expression of MARCH8, an E3 ubiquitin ligase, is associated with growth of esophageal tumor

Background

Herein, for the first time, we report aberrant expression of membrane-associated RING-CH8 (MARCH8) in human esophageal squamous cell carcinoma. MARCH8 is a member of the recently discovered MARCH family of really interesting new genes (RING) E3 ligases. Though initial studies primarily focused on its immunomodulatory role, the newly discovered targets of this E3 ligase point towards its possible role in other biological processes such as embryogenesis and inhibition of apoptosis. However, its relevance in cancers is yet to be elucidated.

Methods

We carried out quantitative real time PCR and immunohistochemistry to examine the levels of MARCH8 mRNA and protein in esophageal squamous cell carcinoma tissues. The role of MARCH8 in esophageal cancer cells was evaluated by cell proliferation, clonogenic and migration/invasion assays and flow cytometry with MARCH8 gene knockdown.

Results

Significantly increased expression of MARCH8 mRNA was found in esophageal squamous cell carcinoma as compared to distant matched non-malignant tissues (p = 0.024, AUC = 0.654). Immunohistochemical analysis revealed overexpression of MARCH8 protein in 86% of esophageal squamous cell carcinoma tissues (p < 0.001, AUC = 0.908). Interestingly, intense nuclear staining of MARCH8 protein was detected in cancer cells in addition to its cytoplasmic expression. Knockdown of MARCH8 resulted in decreased proliferation, migration, invasion and clonogenic potential of esophageal cancer cells. In addition to this, silencing of MARCH8 induced apoptosis in esophageal cancer cells which was measured by cell cycle distribution assay which showed increase in sub G0 and G2/M populations (cell death) and decrease in S-phase population. To further check the type of apoptosis induced by MARCH8 silencing, annexin assay was performed which showed significant increase in the number of cells in early apoptotic phase.

Conclusions

Overall, increased expression of MARCH8 gene in preneoplastic and neoplastic esophageal tissues and its knockdown effect on cancer cell properties demonstrated herein points towards the potential role of this protein in esophageal tumorigenesis.

The long non-coding RNA NKILA inhibits the invasion-metastasis cascade of malignant melanoma via the regulation of NF-ĸB

The long non-coding RNA (lncRNA) NKILA has been reported to participate in the development of human cancers. The purpose of this study was to explore the potential role of lncRNA-NKILA, which acts through NF-ĸB, in the process of melanoma development. Real-time PCR (qRT-PCR) showed that NKILA was expressed at low levels in human melanoma tissues. The area under the ROC curve of NKILA was 0.875, which indicated that NKILA may be a potential diagnostic biomarker of melanoma. Our results also indicated that NKILA inhibited the progression of cell proliferation, migration, and invasion, and promoted apoptosis of melanoma cells. Furthermore, qRT-PCR showed that NF-κB, which was negatively correlated with NKILA, was highly expressed in human melanoma tissues. Moreover, our results indicated that NKILA inhibited the carcinogenesis of melanoma cells through the inhibition of NF-ĸB in vitro. More importantly, we found that NKILA suppressed the growth of melanoma tumors via NF-ĸB in vivo. In conclusion, NKILA suppressed the development of malignant melanoma via the regulation of NF-ĸB and may be a potential therapeutic target in patients with melanoma.

MARCH1 E3 Ubiquitin Ligase Dampens the Innate Inflammatory Response by Modulating Monocyte Functions in Mice

Ubiquitination was recently identified as a central process in the pathogenesis and development of numerous inflammatory diseases, such as obesity, atherosclerosis, and asthma. Treatment with proteasomal inhibitors led to severe side effects because ubiquitination is heavily involved in a plethora of cellular functions. Thus, new players regulating ubiquitination processes must be identified to improve therapies for inflammatory diseases. In addition to their role in adaptive immunity, endosomal MHC class II (MHCII) molecules were shown to modulate innate immune responses by fine tuning the TLR4 signaling pathway. However, the role of MHCII ubiquitination by membrane associated ring-CH-type finger 1 (MARCH1) E3 ubiquitin ligase in this process remains to be assessed. In this article, we demonstrate that MARCH1 is a key inhibitor of innate inflammation in response to bacterial endotoxins. The higher mortality of March1^-/- mice challenged with a lethal dose of LPS was associated with significantly stronger systemic production of proinflammatory cytokines and splenic NK cell activation; however, we did not find evidence that MARCH1 modulates LPS or IL-10 signaling pathways. Instead, the mechanism by which MARCH1 protects against endotoxic shock rests on its capacity to promote the transition of monocytes from Ly6C^Hi to Ly6C^+/- Moreover, in competitive bone marrow chimeras, March1^-/- monocytes and polymorphonuclear neutrophils outcompeted wild-type cells with regard to bone marrow egress and homing to peripheral organs. We conclude that MARCH1 exerts MHCII-independent effects that regulate the innate arm of immunity. Thus, MARCH1 might represent a potential new target for emerging therapies based on ubiquitination reactions in inflammatory diseases.