Targeting tumorous Circ-E-Cadherinencoded C-E-Cad inhibits the recruitment and function of breast cancer-associated myeloid-derived suppressor cells.

We previously demonstrated that the C-E-cad protein encoded by circ-E-cadherin promotes the self-renewal of glioma stem cells. The expression pattern of C-E-cad in breast cancer and its potential function in the tumor microenvironment are unclear. The expression of circ-E-cadherin and C-E-cad was detected in breast cancer specimens. The influence of C-E-cad expression on MDSCs was assessed using FACS and in vivo tumorigenesis experiments. The synergistic effect of anti-C-E-cad and anti-PD-1 antibodies was validated in vivo. circ-E-cadherin and the encoded protein C-E-cad were found to be upregulated in breast cancer vs. normal samples. C-E-cad promotes the recruitment of MDSCs, especially PMN-MDSCs. C-E-cad activates EGFR signaling in tumor cells and promotes the transcription of CXCL8; moreover, C-E-cad binds to MDSCs and maintains glycolysis in PMN-MDSCs. Targeting C-E-cad enhanced anti-PD-1 efficiency. Our data suggested that C-E-cad is markedly overexpressed in breast cancer and promotes MDSC recruitment and survival. Targeting C-E-cad increases the efficacy of immune checkpoint inhibitor therapy.

AMPK phosphorylates and stabilises copper transporter 1 to synergise metformin and copper chelator for breast cancer therapy.

BACKGROUND: Predominant roles of copper and its transporter, copper transporter 1 (CTR1), in tumorigenesis have been explored recently; however, the upstream regulation of CTR1 and combinational intervention of copper chelators in malignancies remain largely unclear. METHODS: CRISPR/Cas9-based kinome screening was used to identify the CTR1 upstream kinases. Immunofluorescence assays were utilised to detect CTR1 localisation. In vitro kinase assays and mass spectrometry were performed to detect CTR1 phosphorylation. Ubiquitination assays were performed to validate CTR1 stability. Colony formation, EdU labelling, Annexin V-FITC/PI-based apoptosis assays were carried out to detect the drug effect on cell growth and apoptosis. Xenografted mouse models were employed to investigate drug effects in vivo. RESULTS: We identify that CTR1 undergoes AMPK-mediated phosphorylation, which enhances CTR1 stabilisation and membrane translocation by affecting Nedd4l interaction, resulting in increased oncogenic roles in breast cancer. Importantly, activation of AMPK with its agonist metformin markedly enhances CTR1 levels, and leads to the combinational usage of AMPK agonists and copper chelators for breast cancer treatment. CONCLUSIONS: Our findings not only reveal the crosstalk between energy response and copper uptake via AMPK-mediated CTR1 phosphorylation and stability but also highlight the strategy to combat breast cancer by a combination of AMPK agonists and copper chelators. SIGNIFICANCE: The connection between energy response and copper homoeostasis is linked by AMPK phosphorylating and stabilising CTR1, which provides a promising strategy to combat breast cancer by combining AMPK agonists and copper chelators.

Apolipoprotein A1 is negatively associated with male papillary thyroid cancer patients: a cross-sectional study of single academic center in China.

BACKGROUND: Papillary thyroid cancer (PTC) is the most common type of thyroid cancer and the incidence of PTC has continued to increase over the past decades. Many studies have shown that obesity is an independent risk factor for PTC and obese PTC patients tend to have a relative larger tumor size and higher grade of tumor stage. Obesity is associated with disordered lipid metabolism and the relationship between serum lipids and PTC remains unclear. Therefore, this study aimed to investigate the association between serum lipid level and PTC. METHODS: We retrospectively analyzed 1018 PTC patients diagnosed and treated in our hospital, all these cases were first diagnosed with PTC and had complete clinical information including ultrasound reports before surgery, serum lipid (CHOL, TG, HDL-c, LDL-c, Apo-A1, Apo-B, Apo-E) results, surgical records and pathological reports. RESULTS: None of these lipid markers were associated with tumor size in the whole cohort and in the female group. In the male group, on crude analysis, Apo-A1 showed a marginally association with tumor size, [OR = 0.158 (0.021-1.777)], p = 0.072. After adjusting for age and multifocality, Apo-A1 showed a significant association with tumor size [OR = 0.126 (0.016-0.974)], p = 0.047. This association become more apparent in a young male subgroup, [OR = 0.051 (0.005-0.497)], p = 0.009. CHOL, TG, HDL-c, LDL-c, Apo-B, Apo-E did not show significant association with tumor size. As for LNM, neither in the male group nor in the female group were found to be associated with any serum lipid biomarkers. CONCLUSION: As PTC incidences continues to increase, our findings demonstrated a negatively association between PTC and apoA-1 in male PTC patients, which may contribute to further investigation concerning diagnosing and preventing this most common type of thyroid cancer.

127aa encoded by circSpdyA promotes FA synthesis and NK cell repression in breast cancers.

Lipid metabolism reprogram plays key roles in breast cancer tumorigenesis and immune escape. The underlying mechanism and potential regulator were barely investigated. We thus established an in vivo tumorigenesis model, mice-bearing breast cancer cells were treated with an ordinary diet and high-fat diet, species were collected and subjected to circRNA sequence to scan the potential circRNAs regulating the lipid metabolism. CircSpdyA was one of the most upregulated circRNAs and had the potential to encode a 127-aa micro peptide (referred to as 127aa). 127 aa promotes tumorigenesis through promoting the fatty acid de novo synthesis by directly binding to FASN. Single-cell sequence indicated 127aa inhibited NK cell infiltration and function. This was achieved by inhibiting the transcription of NK cell activators epigenetically. Moreover, lipid-laden from 127aa positive cancer cells transferred to NK cells inhibited the cytotoxicity. Taken together, circSpdyA encoded 127aa promotes fatty acid de novo synthesis through directly binding with FASN and induced NK cell repression by inhibiting the transcription of NK cell activators.

Investigating the Effects of AL049796.1 Silencing in Inhibiting High Glucose-Induced Colorectal Cancer Progression.

Patients with colorectal cancer (CRC) and diabetes share many risk factors. Despite a strong association between diabetes and CRC being widely studied and confirmed, further genetic research is needed. This study found higher AL049796.1 and TEA domain transcription factor 1 (TEAD1) levels (both mRNA and protein) in CRC tissues of diabetic patients compared with nondiabetics, but no significant difference in miR-200b-3p levels. A positive correlation between AL049796.1 and TEAD1 protein existed regardless of diabetes status, whereas miR-200b-3p was only negatively correlated with TEAD1 protein in nondiabetic CRC tissues. In vitro experiments have shown that high glucose (HG) treatment increased AL049796.1 in CRC cells, and AL049796.1 silencing reduced HG-induced proliferation, migration and invasion, as well as connective tissue growth factor, cysteine-rich angiogenic inducer 61, and epidermal growth factor receptor protein expression. Mechanistic investigations indicated that AL049796.1 could mitigate suppression of miR-200b-3p on TEAD1 posttranscriptionally by acting as a competitive binder. In vivo, subcutaneous CRC tumors in streptozotocin (STZ)-induced mice grew significantly faster; AL049796.1 silencing did not affect the growth of subcutaneous CRC tumors but significantly reduced that of STZ-induced mice. Our study suggests that AL049796.1 independently contributes to the risk of CRC in diabetic patients, highlighting its potential as both a therapeutic target and a novel biomarker for CRC among individuals with diabetes.

Phase separation of phospho-HDAC6 drives aberrant chromatin architecture in triple-negative breast cancer.

How dysregulated liquid-liquid phase separation (LLPS) contributes to the oncogenesis of female triple-negative breast cancer (TNBC) remains unknown. Here we demonstrate that phosphorylated histone deacetylase 6 (phospho-HDAC6) forms LLPS condensates in the nuclei of TNBC cells that are essential for establishing aberrant chromatin architecture. The disordered N-terminal domain and phosphorylated residue of HDAC6 facilitate effective LLPS, whereas nuclear export regions exert a negative dominant effect. Through phase-separation-based screening, we identified Nexturastat A as a specific disruptor of phospho-HDAC6 condensates, which effectively suppresses tumor growth. Mechanistically, importin-ß interacts with phospho-HDAC6, promoting its translocation to the nucleus, where 14-3-3θ mediates the condensate formation. Disruption of phospho-HDAC6 LLPS re-established chromatin compartments and topologically associating domain boundaries, leading to disturbed chromatin loops. The phospho-HDAC6-induced aberrant chromatin architecture affects chromatin accessibility, histone acetylation, RNA polymerase II elongation and transcriptional profiles in TNBC. This study demonstrates phospho-HDAC6 LLPS as an emerging mechanism underlying the dysregulation of chromatin architecture in TNBC.

Small interfering RNA targeting Rac1 sensitizes colon cancer to dihydroartemisinin-induced cell cycle arrest and inhibited cell migration by suppressing NFκB activity.

Dihydroartemisinin (DHA) has recently shown antitumor activity in various cancer cells. The small GTPase Rac1 regulates many cellular processes, including cytoskeletal reorganization, cell migration, proliferation, and survival. In addition, Rac1 plays a major role in activating NFκB-mediated transcription. Both Rac1 and NFκB regulate many properties of the malignant phenotype, including anchorage-independent proliferation and survival, metastasis, and angiogenesis. In this study, for the first time, we demonstrated that Rac1 knockdown can enhance DHA-induced growth inhibition, cell cycle arrest, apoptosis, and migration in both HCT116 and RKO cell lines in vitro. The mechanism is due partially to DHA, and Rac1 siRNA deactivates NFκB activity, so as to decrease tremendously the expression of its target gene products, such as PCNA, cyclin D1, and CDK4; and increase the expression of p21, cleaved-caspase-3, and cleaved-PARP. In our in vivo studies, DHA also manifested remarkably enhanced antitumor effect when combined with Rac1 siRNA. We concluded that inhibition of NFκB activation is one of the mechanisms that Rac1 siRNA dramatically promotes DHAs antitumor effect on human colon cancer.

AKT Blocks SIK1-Mediated Repression of STAT3 to Promote Breast Tumorigenesis.

The PI3K-AKT signaling pathway is frequently dysregulated in cancer, and it is hyperactivated in approximately 50% of breast cancers. Although inhibitors directly targeting the PI3K-AKT axis have been developed, clinical efficacy has been limited to only a subset of patients. Identification of mechanisms underlying AKT-driven tumorigenesis could lead to alternative approaches to block pathway signaling and suppress breast tumor growth. Mass spectrometry-based analyses demonstrated that salt-inducible kinase 1 (SIK1) binds AKT and undergoes AKT-mediated phosphorylation, which compromises SIK1 tumor-suppressive functions. As a result, AKT relieved the binding and repression of STAT3 by SIK1 in a phosphorylation-dependent manner, resulting in breast cell tumorigenesis. Following AKT-mediated phosphorylation, SIK1 interacted with 14-3-3 and was translocated to the cytoplasm where the isomerase Pin1 facilitated SIK1 interaction with the E3 ligase ITCH to promote SIK1 ubiquitination and subsequent degradation. These findings indicate that SIK1 is a substrate of AKT that links AKT oncogenic function to STAT3 activation, highlighting targeting of the JAK2-STAT3 axis as a strategy to treat AKT-driven breast cancer. SIGNIFICANCE: AKT binds and phosphorylates SIK1 to overcome SIK1-mediated repression of STAT3, indicating that STAT3 is a potential therapeutic target in breast cancer with hyperactive AKT signaling.

CDK4/6 inhibitor resistance mechanisms and treatment strategies (Review).

In recent years, the incidence rate of breast cancer has increased year by year, and it has become a major threat to the health of women globally. Among all breast cancer subtypes, the hormone receptor (HR)+/human epidermal growth factor receptor 2 (HER2)­ luminal subtype breast cancer is the most common form of breast cancer. Cyclin­dependent kinase 4 and 6 (CDK4/6) inhibitors, the hotspots in the field of targeted therapy for breast cancer, have proved to exhibit a good effect on patients with HR+/HER2­ breast cancer in a number of clinical trials, but the problem of drug resistance is inevitable. At present, three specific CDK4/6 inhibitors (palbociclib, ribociclib and abemaciclib) have been approved by the USA Food and Drug Administration for the first­line treatment of HR+/HER2­ breast cancer. The drug resistance mechanisms of CDK4/6 inhibitors can be divided into cell cycle­specific resistance and cell cycle non­specific resistance. With the discovery of the drug resistance mechanism of CDK4/6 inhibitors, various targeted strategies have been proposed. The present review mainly discusses the mechanism of CDK4/6 inhibitors, drug resistance mechanisms and treatment strategies after resistance.

IKBKE phosphorylates and stabilizes Snail to promote breast cancer invasion and metastasis.

IKBKE, a non-canonical inflammatory kinase, is frequently amplified or activated, and plays predominantly oncogenic roles in human cancers, especially in breast cancer. However, the potential function and underlying mechanism of IKBKE contributing to breast cancer metastasis remain largely elusive. Here, we report that depletion of Ikbke markedly decreases polyoma virus middle T antigen (PyVMT)-induced mouse mammary tumorigenesis and subsequent lung metastasis. Biologically, ectopic expression of IKBKE accelerates, whereas depletion of IKBKE attenuates breast cancer invasiveness and migration in vitro and tumor metastasis in vivo. Mechanistically, IKBKE tightly controls the stability of transcriptional factor Snail in different layers, in particular by directly phosphorylating Snail, which markedly blocks the E3 ligase ß-TRCP1-mediated Snail degradation, resulting in breast cancer epithelial-mesenchymal transition (EMT) and metastasis. These findings together reveal a novel oncogenic function of IKBKE in promoting breast cancer metastasis by governing Snail abundance, and highlight the potential of targeting IKBKE for metastatic breast cancer therapies.

The potent roles of salt-inducible kinases (SIKs) in metabolic homeostasis and tumorigenesis.

Salt-inducible kinases (SIKs) belong to AMP-activated protein kinase (AMPK) family, and functions mainly involve in regulating energy response-related physiological processes, such as gluconeogenesis and lipid metabolism. However, compared with another well-established energy-response kinase AMPK, SIK roles in human diseases, especially in diabetes and tumorigenesis, are rarely investigated. Recently, the pilot roles of SIKs in tumorigenesis have begun to attract more attention due to the finding that the tumor suppressor role of LKB1 in non-small-cell lung cancers (NSCLCs) is unexpectedly mediated by the SIK but not AMPK kinases. Thus, here we tend to comprehensively summarize the emerging upstream regulators, downstream substrates, mouse models, clinical relevance, and candidate inhibitors for SIKs, and shed light on SIKs as the potential therapeutic targets for cancer therapies.

Synergy of GSK-J4 With Doxorubicin in KRAS-Mutant Anaplastic Thyroid Cancer.

BACKGROUND: Anaplastic thyroid cancer is the most aggressive thyroid cancer and has a poor prognosis. At present, there is no effective treatment for it. METHODS: Here, we used different concentrations of GSK-J4 or a combination of GSK-J4 and doxorubicin to treat human Cal-62, 8505C, and 8305C anaplastic thyroid cancer (ATC) cell lines. The in vitro experiments were performed using cell viability assays, cell cycle assays, annexin-V/PI binding assays, Transwell migration assays, and wound-healing assays. Tumor xenograft models were used to observe effects in vivo. RESULTS: The half maximal inhibitory concentration (IC50) of GSK-J4 in Cal-62 cells was 1.502 µM, and as the dose of GSK-J4 increased, more ATC cells were blocked in the G2-M and S stage. The combination of GSK-J4 and doxorubicin significantly increased the inhibitory effect on proliferation, especially in KRAS-mutant ATC cells in vivo (inhibition rate 38.0%) and in vitro (suppresses rate Fa value 0.624, CI value 0.673). The invasion and migration abilities of the KRAS-mutant cell line were inhibited at a low concentration (p < 0.05). CONCLUSIONS: The combination of GSK-J4 with doxorubicin in KRAS-mutant ATC achieved tumor-suppressive effects at a low dose. The synergy of the combination of GSK-J4 and doxorubicin may make it an effective chemotherapy regimen for KRAS-mutant ATC.

Enhanced electrokinetic remediation and simulation of cadmium-contaminated soil by superimposed electric field.

The 'focusing' effect has become a limiting factor for the removal of heavy metals from soils by electrokinetic (EK) remediation. A superimposed electric field EK (SE-EK) method is proposed to address this problem. Two sets of fixed electrodes placed at different positions were switched to move the 'focusing' region of Cd to the cathode by controlling the location of the pH jumping front. Moreover, a model was established to simulate and optimize the process of Cd transport in soil under the superimposed electric field. Results showed that, after 35 d of SE-EK remediation, Cd was mainly accumulated in the soil section near the cathode (S5), where the acid and alkaline fronts converged. The removal rate of Cd in the soil sections from S1 to S4 reached 87.60%, which was 6.13 times that in conventional EK remediation. Meanwhile, the energy utilization efficiency in SE-EK was 6.38 times that in conventional EK. The pH changes and Cd distribution during the SE-EK experiment were simulated well, with good agreement between the modeled and experimental data. The removal of Cd in SE-EK remediation could therefore be optimized through simulating the distribution of Cd in five situations with differences in switching time and electrode position. This research provides valuable technical support for effective EK remediation of heavy metal contaminated soil.

The incidence and survival analysis for anaplastic thyroid cancer: a SEER database analysis.

BACKGROUND: Thyroid carcinoma is the most common malignant endocrine tumor; the anaplastic thyroid cancer subtype is aggressive and has a poor prognosis. However, there is no effective treatment for this disease. METHODS: This study was analyzed using the Surveillance, Epidemiology, and End Results (SEER) database. Joinpoint regression models, linear regression models, Kaplan-Meier survival curves and Cox regression models were used to study the trends in incidence, survival rate and median survival time and to detect the risk factors affecting prognosis in patients with anaplastic thyroid cancer. RESULTS: While the incidence rate and truncated incidence rate fluctuated slightly over the past 30 years, they were relatively stable and had no obvious upward trend (APC = -0.22 and 0.24, respectively, P>0.05). The median survival was 3.16 months, and the survival rate did not improve significantly (the APC values of the 3-, 6-, 9-, and 12-month survival rates were 0.44, 0.35, -0.23 and -0.86, respectively, P>0.05). After subgroup analysis and survival analysis, it was concluded that the prognosis of the patients might be related to their metastatic stage, surgical status, chemotherapy treatment, age and socioeconomic status at the time of diagnosis (P<0.05). Total thyroidectomy is superior to other methods and is beneficial in prolonging the life of patients and improving the overall survival rate (the median survival was 10 months, and the 6-month survival rate was 59.26%). CONCLUSION: The incidence trend for anaplastic thyroid cancer over the last 30 years was stable, and the survival rate and median survival time were not significantly improved. The prognosis of the patients may be related to their metastatic stage, age, socioeconomic status, surgical status and chemotherapy treatment.

Expression and clinicopathological significance of EED, SUZ12 and EZH2 mRNA in colorectal cancer.

BACKGROUND AND OBJECTIVES: Enhancer of zeste 2 (EZH2), embryonic ectoderm development (EED), and suppressor of zeste 12 homolog (SUZ12), the key component of polycomb repressive complex 2, are of great importance in human cancer pathogenesis. This study was designed to investigate the clinical and prognostic significances of EZH2, EED and SUZ12 in colorectal cancer (CRC) patients. METHODS: The expression of EZH2, EED and SUZ12 mRNA was evaluated in 82 primary CRC and paired non-cancerous mucosa samples by qRT-PCR. RESULTS: We found that overall EZH2, EED and SUZ12 mRNA expression in the CRC tissues was significantly increased than in the non-cancerous tissue (p < 0.05). Increased EZH2, EED and SUZ12 mRNA expression was directly correlated with primary tumor size, regional lymph node metastases, distant metastasis and AJCC stage. Furthermore, CRC patients with higher level of EED, SUZ12 or EZH2 showed a worse disease-free survival (DFS) (p < 0.01). In multivariate analysis, the increased EZH2 expression may be a risk factor for the patients' 3-year DFS (HR 2.517; 95% CI 1.104, 5.736; p = 0.028). Furthermore, the k-means cluster analysis showed that high mRNA expression of EED, SUZ12 and EZH2 was significantly correlated with the aggressive clinical behavior and poor prognosis. CONCLUSIONS: High expression of EED, SUZ12 and EZH2 might contribute to the CRC development/progression.