Circular RNAs (circRNA) are a class of covalently closed single-stranded RNAs that have been implicated in cancer progression. Here we identify circNDUFB2 to be downregulated in non-small cell lung ...cancer (NSCLC) tissues, and to negatively correlate with NSCLC malignant features. Elevated circNDUFB2 inhibits growth and metastasis of NSCLC cells. Mechanistically, circNDUFB2 functions as a scaffold to enhance the interaction between TRIM25 and IGF2BPs, a positive regulator of tumor progression and metastasis. This TRIM25/circNDUFB2/IGF2BPs ternary complex facilitates ubiquitination and degradation of IGF2BPs, with this effect enhanced by N
-methyladenosine (m
A) modification of circNDUFB2. Moreover, circNDUFB2 is also recognized by RIG-I to activate RIG-I-MAVS signaling cascades and recruit immune cells into the tumor microenvironment (TME). Our data thus provide evidences that circNDUFB2 participates in the degradation of IGF2BPs and activation of anti-tumor immunity during NSCLC progression via the modulation of both protein ubiquitination and degradation, as well as cellular immune responses.
Circular RNAs (circRNAs) are identified as vital regulators in a variety of cancers. However, the role of circRNA in lung squamous cell carcinoma (LUSC) remains largely unknown. Herein, we explore ...the expression profiles of circRNA and mRNA in 5 paired samples of LUSC. By analyzing the co-expression network of differentially expressed circRNAs and dysregulated mRNAs, we identify that a cell cycle-related circRNA, circTP63, is upregulated in LUSC tissues and its upregulation is correlated with larger tumor size and higher TNM stage in LUSC patients. Elevated circTP63 promotes cell proliferation both in vitro and in vivo. Mechanistically, circTP63 shares miRNA response elements with FOXM1. circTP63 competitively binds to miR-873-3p and prevents miR-873-3p to decrease the level of FOXM1, which upregulates CENPA and CENPB, and finally facilitates cell cycle progression.
Several of the thousands of human long noncoding RNAs (lncRNAs) have been functionally characterized, yet their potential involvement in hepatocellular carcinoma (HCC) remains poorly understood.
...LncRNA-HOXD-AS1 was identified by microarray and validated by real-time PCR. The clinicopathological significance of HOXD-AS1 was analyzed by Kaplan-Meier method. Chromatin immunoprecipitation was conducted to examine the mechanism of HOXD-AS1 upregulation. The role of HOXD-AS1 in HCC cells was assessed both in vitro and in vivo. ceRNA function of HOXD-AS1 was evaluated by RNA immunoprecipitation and biotin-coupled miRNA pull down assays.
In this study, we found that HOXD-AS1 was significantly upregulated in HCC tissues. Clinical investigation demonstrated high expression level of HOXD-AS1 was associated with poor prognosis and high tumor node metastasis stage of HCC patients, and was an independent risk factor for survival. Moreover, our results revealed that STAT3 could specifically interact with the promoter of HOXD-AS1 and activate HOXD-AS1 transcription. Knockdown of HOXD-AS1 significantly inhibited migration and invasion of HCC cells in vitro and distant lung metastasis in vivo. Additionally, HOXD-AS1 was enriched in the cytoplasm, and shared miRNA response elements with SOX4. Overexpression of HOXD-AS1 competitively bound to miR-130a-3p that prevented SOX4 from miRNA-mediated degradation, thus activated the expression of EZH2 and MMP2 and facilitated HCC metastasis.
In summary, HOXD-AS1 is a prognostic marker for HCC patients and it may play a pro-metastatic role in hepatocarcinogenesis.
Liver cancer remains difficult to treat, owing to a paucity of drugs that target critical dependencies
; broad-spectrum kinase inhibitors such as sorafenib provide only a modest benefit to patients ...with hepatocellular carcinoma
. The induction of senescence may represent a strategy for the treatment of cancer, especially when combined with a second drug that selectively eliminates senescent cancer cells (senolysis)
. Here, using a kinome-focused genetic screen, we show that pharmacological inhibition of the DNA-replication kinase CDC7 induces senescence selectively in liver cancer cells with mutations in TP53. A follow-up chemical screen identified the antidepressant sertraline as an agent that kills hepatocellular carcinoma cells that have been rendered senescent by inhibition of CDC7. Sertraline suppressed mTOR signalling, and selective drugs that target this pathway were highly effective in causing the apoptotic cell death of hepatocellular carcinoma cells treated with a CDC7 inhibitor. The feedback reactivation of mTOR signalling after its inhibition
is blocked in cells that have been treated with a CDC7 inhibitor, which leads to the sustained inhibition of mTOR and cell death. Using multiple in vivo mouse models of liver cancer, we show that treatment with combined inhibition of of CDC7 and mTOR results in a marked reduction of tumour growth. Our data indicate that exploiting an induced vulnerability could be an effective treatment for liver cancer.
To overcome the shortcomings of the temperature sensitivity of exterior flexible facing tiles (EFFIs), a series of crosslinking carboxylic styrene-acrylate (SA) latices were prepared via the ...semicontinuous seed emulsion polymerization of glycidyl methacrylate (GMA), methacrylic acid (MAA), acrylic acid (AA), butyl acrylate (BA), and styrene (St), and were applied as binders to fabricate EFFTs with mineral powder. The obtained latices exhibited Bragg diffraction because of the narrow particle size distribution. Owing to the low dosage of emulsifiers and the crosslinking reaction between the epoxy group and the carboxyl group, the latex films displayed excellent water resistance, with water adsorption as low as 7.1%. The tensile test, differential scanning calorimeter (DSC) test, and dynamic mechanical analysis (DMA) indicated that at a GMA dosage of 4–6% the latex films had high mechanical strengths, which remained relatively stable in the temperature range of 10 to 40 °C. The optimal AA dosage was found in the range of 2 to 3%, at which the wet mixture exhibited good processability, conducive to forming an EFFT with a compact microstructure. Using the optimal SA latex, the obtained EFFT displayed a series of improved performances, including low water absorption, high mechanical strength, and stable self-supporting ability over a wide temperature range, exhibiting the application potential in the decoration and construction industries.
Mitochondria lie at the heart of innate immunity, and aberrant mitochondrial activity contributes to immune activation and chronic inflammatory diseases, including liver cancers. Mitophagy is a ...selective process for removing dysfunctional mitochondria. The link between mitophagy and inflammation in tumorigenesis remains largely unexplored. We observed that FUN14 domain‐containing 1 (FUNDC1), a previously characterized mitophagy receptor, accumulates in most human hepatocellular carcinomas (HCCs), and we thus explored the role of FUNDC1‐mediated mitophagy in HCC initiation and progression in a mouse model in which HCC is induced by the chemical carcinogen, diethylnitrosamine (DEN). We showed that specific knockout of FUNDC1 in hepatocytes promotes the initiation and progression of DEN‐induced HCC, whereas FUNDC1 transgenic hepatocytes protect against development of HCC. Hepatocyte‐specific FUNDC1 ablation results in the accumulation of dysfunctional mitochondria and triggers a cascade of events involving inflammasome activation and hyperactivation of Janus kinase/signal transducer and activator of transcription signaling. Specifically, cytosolic mitochondrial DNA (mtDNA) release and caspase‐1 activation are increased in FUNDC1‐depleted hepatocytes. This subsequently results in the elevated release of proinflammatory cytokines, such as interleukin‐1β (IL1β) and hyperproliferation of hepatocytes. Conclusion: Our results suggest that FUNDC1 suppresses HCC initiation by reducing inflammasome activation and inflammatory responses in hepatocytes, whereas up‐regulation of FUNDC1 expression at the late stage of tumor development may benefit tumor growth. Our study thus describes a mechanistic link between mitophagic modulation of inflammatory response and tumorigenesis, and further implies that FUNDC1‐mediated mitophagy and its related inflammatory response may represent a therapeutic target for liver cancer.
The dependency of cancer cells on glutamine may be exploited therapeutically as a new strategy for treating cancers that lack druggable driver genes. Here we found that human liver cancer was ...dependent on extracellular glutamine. However, targeting glutamine addiction using the glutaminase inhibitor CB-839 as monotherapy had a very limited anticancer effect, even against the most glutamine addicted human liver cancer cells. Using a chemical library, we identified V-9302, a novel inhibitor of glutamine transporter ASCT2, as sensitizing glutamine dependent (GD) cells to CB-839 treatment. Mechanically, a combination of CB-839 and V-9302 depleted glutathione and induced reactive oxygen species (ROS), resulting in apoptosis of GD cells. Moreover, this combination also showed tumor inhibition in HCC xenograft mouse models in vivo. Our findings indicate that dual inhibition of glutamine metabolism by targeting both glutaminase and glutamine transporter ASCT2 represents a potential novel treatment strategy for glutamine addicted liver cancers.
Heat shock proteins (HSPs) are highly conserved proteins, which are expressed at low levels under normal conditions, but significantly induced in response to cellular stresses. As molecular ...chaperones, HSPs play crucial roles in protein homeostasis, apoptosis, invasion and cellular signaling transduction. The induction of HSPs is an important part of heat shock response, which could help cancer cells to adapt to stress conditions. Because of the constant stress condition in tumor microenvironment, HSPs overexpression is widely reported in many human cancers. In light of the significance of HSPs for cancer cells to survive and obtain invasive phenotype under stress condition, HSPs are often associated with poor prognosis and treatment resistance in many types of human cancers. It has been described that upregulation of HSPs may serve as diagnostic and prognostic markers in hepatocellular carcinoma (HCC). Targeting HSPs with specific inhibitor alone or in combination with chemotherapy regimens holds promise for the improvement of outcomes for HCC patients. In this review, we summarize the expression profiles, functions and molecular mechanisms of HSPs (HSP27, HSP70 and HSP90) as well as a HSP‐like protein (clusterin) in HCC. In addition, we address progression and challenges in targeting these HSPs as novel therapeutic strategies in HCC.
Hepatocellular carcinoma (HCC)-the most common form of liver cancer-is an aggressive malignancy with few effective treatment options
. Lenvatinib is a small-molecule inhibitor of multiple receptor ...tyrosine kinases that is used for the treatment of patients with advanced HCC, but this drug has only limited clinical benefit
. Here, using a kinome-centred CRISPR-Cas9 genetic screen, we show that inhibition of epidermal growth factor receptor (EGFR) is synthetic lethal with lenvatinib in liver cancer. The combination of the EGFR inhibitor gefitinib and lenvatinib displays potent anti-proliferative effects in vitro in liver cancer cell lines that express EGFR and in vivo in xenografted liver cancer cell lines, immunocompetent mouse models and patient-derived HCC tumours in mice. Mechanistically, inhibition of fibroblast growth factor receptor (FGFR) by lenvatinib treatment leads to feedback activation of the EGFR-PAK2-ERK5 signalling axis, which is blocked by EGFR inhibition. Treatment of 12 patients with advanced HCC who were unresponsive to lenvatinib treatment with the combination of lenvatinib plus gefitinib (trial identifier NCT04642547) resulted in meaningful clinical responses. The combination therapy identified here may represent a promising strategy for the approximately 50% of patients with advanced HCC who have high levels of EGFR.
Display omitted
•ERK2 inhibition was identified as an enhancer of the response to sorafenib in HCC.•Selumetinib increases the response of sorafenib in HCC cell lines with high p-ERK.•The synthetic ...lethal effect is derived from synergistic inhibition of ERK kinase.•The combination therapy is most likely to be effective in tumors with high p-ERK.
Treatment of liver cancer remains challenging because of a paucity of drugs that target critical dependencies. Sorafenib is a multikinase inhibitor that is approved as the standard therapy for patients with advanced hepatocellular carcinoma, but it only provides limited survival benefit. In this study we aimed to identify potential combination therapies to improve the clinical response to sorafenib.
To investigate the cause of the limited therapeutic effect of sorafenib, we performed a CRISPR-Cas9 based synthetic lethality screen to search for kinases whose knockout synergizes with sorafenib. Synergistic effects of sorafenib and selumetinib on cell apoptosis and phospho-ERK (p-ERK) were analyzed by caspase-3/7 apoptosis assay and western blot, respectively. p-ERK was measured by immunochemical analysis using a tissue microarray containing 78 liver cancer specimens. The in vivo effects of the combination were also measured in two xenograft models.
We found that suppression of ERK2 (MAPK1) sensitizes several liver cancer cell lines to sorafenib. Drugs inhibiting the MEK (MEK1/2 MAP2K1/2) or ERK (ERK1/2 MAPK1/3) kinases reverse unresponsiveness to sorafenib in vitro and in vivo in a subset of liver cancer cell lines characterized by high levels of active p-ERK, through synergistic inhibition of ERK kinase activity.
Our data provide a combination strategy for treating liver cancer and suggest that tumors with high basal p-ERK levels, which are seen in approximately 30% of liver cancers, are most likely to benefit from such combinatorial treatment.
Sorafenib is approved as the standard therapy for patients with advanced hepatocellular carcinoma, but only provides limited survival benefit. Herein, we found that inhibition of the kinase ERK2 increases the response to sorafenib in liver cancer. Our data indicate that a combination of sorafenib and a MEK inhibitor is most likely to be effective in tumors with high basal phospho-ERK levels.
PDF
