Four and a half LIM domains 2 (FHL2) attenuates tumorigenesis of gastrointestinal stromal tumors (GISTs) by negatively regulating KIT signaling.

Gastrointestinal stromal tumors (GISTs) are predominately induced by KIT mutants. In this study, we found that four and a half LIM domains 2 (FHL2) was highly expressed in GISTs and KIT signaling dramatically increased FHL2 transcription while FHL2 inhibited KIT transcription. In addition, our results showed that FHL2 associated with KIT and increased the ubiquitination of both wild-type KIT and primary KIT mutants in GISTs, leading to decreased expression and activation of KIT although primary KIT mutants were less inhibited by FHL2 than wild-type KIT. In the animal experiments, loss of FHL2 expression in mice carrying germline KIT/V558A mutation which can develop GISTs resulted in increased tumor growth, but increased sensitivity of GISTs to imatinib treatment which is used as the first-line targeted therapy of GISTs, suggesting that FHL2 plays a role in the response of GISTs to KIT inhibitor. Unlike wild-type KIT and primary KIT mutants, we further found that FHL2 didn't alter the expression and activation of drug-resistant secondary KIT mutants. Taken together, our results indicated that FHL2 acts as the negative feedback of KIT signaling in GISTs while primary KIT mutants are less sensitive and secondary KIT mutants are resistant to the inhibition of FHL2.

The role of Connexin26 regulated by MiR-2114-3p in the pathogenesis of ovarian cancer.

OBJECTIVES: The purpose of our research was to determine the expression of Cx26 and miR-2114-3p, and their effects on proliferation, migration, and invasion in ovarian cancer and their mechanisms. MATERIALS AND METHODS: Transcriptome sequencing was performed and differentially expressed Cx26 was screened. The mRNA and protein levels of Cx26 in EOC and normal ovarian tissues were verified. The relationship between Cx26 levels and prognostics was analyzed. Cx26 Lentiviral vectors were constructed to detect its effect on ovarian cancer. WB verified that PI3K/AKT pathway was the possible signal pathway regulated by Cx26. The interaction between miR-2114-3p and Cx26 was detected by double luciferase reporter assay and qrt-PCR. CCK8, clone formation, transwell, and flow cytometry assays were conducted in cells transfected miR-2114-3p plasmids. The vivo experiment investigated the effects of Cx26 on subcutaneous tumor growth, PI3K expression, proliferation proteins Ki67 and PCNA. RESULTS: Cx26 was up-regulated in EOC tissue and cell lines, and was associated with poor prognosis of ovarian cancer, while miR-2114-3p was down-regulated in EOC cell lines. Cx26 was a direct target of miR-2114-3p. Cx26 overexpression and miR-2114-3p inhibition promoted the growth, motility, invasiveness, and S phase arrest of EOC cells. Additionally, Cx26 could activated PI3K pathway whatever in vivo and in vitro. CONCLUSIONS: Dysregulation of Cx26 is critical in EOC patients. Manipulation of this mechanism may influence the survival of EOC patients. MiR-2114-3p regulates the tumor-promoting activity of Cx26 in EOC. By inhibiting the PI3K pathway or knocking down Cx26 effectively inhibits tumor growth in EOC cells and Nude mouse model.

SPRY4 inhibits and sensitizes the primary KIT mutants in gastrointestinal stromal tumors (GISTs) to imatinib.

BACKGROUND: KIT is frequently mutated in gastrointestinal stromal tumors (GISTs), and the treatment of GISTs largely relies on targeting KIT currently. In this study, we aimed to investigate the role of sprouty RTK signaling antagonist 4 (SPRY4) in GISTs and related mechanisms. METHODS: Ba/F3 cells and GIST-T1 cell were used as cell models, and mice carrying germline KIT/V558A mutation were used as animal model. Gene expression was examined by qRT-PCR and western blot. Protein association was examined by immunoprecipitation. RESULTS: Our study revealed that KIT increased the expression of SPRY4 in GISTs. SPRY4 was found to bind to both wild-type KIT and primary KIT mutants in GISTs, and inhibited KIT expression and activation, leading to decreased cell survival and proliferation mediated by KIT. We also observed that inhibition of SPRY4 expression in KITV558A/WT mice led to increased tumorigenesis of GISTs in vivo. Moreover, our results demonstrated that SPRY4 enhanced the inhibitory effect of imatinib on the activation of primary KIT mutants, as well as on cell proliferation and survival mediated by the primary KIT mutants. However, in contrast to this, SPRY4 did not affect the expression and activation of drug-resistant secondary KIT mutants, nor did it affect the sensitivity of secondary KIT mutants to imatinib. These findings suggested that secondary KIT mutants regulate a different downstream signaling cascade than primary KIT mutants. CONCLUSIONS: Our results suggested that SPRY4 acts as negative feedback of primary KIT mutants in GISTs by inhibiting KIT expression and activation. It can increase the sensitivity of primary KIT mutants to imatinib. In contrast, secondary KIT mutants are resistant to the inhibition of SPRY4.

NKD1 targeting PCM1 regulates the therapeutic effects of homoharringtonine on colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is the most common primary malignancy. Recently, antineoplastic attributes of homoharringtonine (HHT) have attracted lots of attention. This study investigated the molecular target and underlying mechanism of HHT in the CRC process by using a cellular and animal models. METHODS: This study first detected the effects of HHT on the proliferation, cell cycle and apoptosis ability of CRC cells using CCK-8, Edu staining, flow cytometry and Western blotting assay. In vitro recovery experiment and in vivo tumorigenesis experiment were used to detect the targeted interaction between HHT and NKD1. After that, the downstream target and mechanism of action of HHT targeting NKD1 was determined using quantitative proteomics combined with co-immunoprecipitation/immunofluorescence assay. RESULTS: HHT suppressed CRC cells proliferation by inducing cell cycle arrest and apoptosis in vitro and vivo. HHT inhibited NKD1 expression in a concentration and time dependent manner. NKD1 was overexpressed in CRC and its depletion enhanced the therapeutic sensitivity of HHT on CRC, which indicating that NKD1 plays an important role in the development of CRC as the drug delivery target of HHT. Furthermore, proteomic analysis revealed that PCM1 participated the process of NKD1-regulated cell proliferation and cell cycle. NKD1 interacted with PCM1 and promoted PCM1 degradation through the ubiquitin-proteasome pathway. The overexpression of PCM1 effectively reversed the inhibition of siNKD1 on cell cycle. CONCLUSIONS: The present findings revealed that HHT blocked NKD1 expression to participate in inhibiting cell proliferation and inducing cell apoptosis, ultimately leading to obstruction of CRC development through NKD1/PCM1 dependent mechanism. Our research provide evidence for clinical application of NKD1-targeted therapy in improving HHT sensitivity for CRC treatment.

Integrative analysis of differentially expressed mRNAs and proteins induced by PGC-1ß in breast cancer cells.

Breast cancer is one of the most frequent malignancies in females. The molecular mechanism of how breast cancer development and recurrence still need to be explored. Peroxisome gamma coactivator-1ß (PGC-1ß) was engaged in cancer energy metabolism and tumor genesis. However, the mechanisms of PGC-1ß in breast cancer have not been fully understood. In this study, PCG-1ß overexpressed and knockdown vectors were transferred into MCF-7 cells. With the association-quantitative connection analysis, the different expressions of mRNAs and proteins were examined. Additionally, the terms on differentially expressed mRNAs and proteins were enriched by GO and KEGG. Based on the results, 1872 differentially expressed genes were identified in the up-regulated of PGC-1ß group, and 1318 genes were found in the down-regulated of PGC-1ß cells. With the label-free technique, 221 differentially expressed proteins were screened in PGC-1ß up-regulated group, and 459 proteins were identified in PGC-1ß down-regulated group. Correlation analysis showed that 49 significantly expressed mRNA-protein pairs in OV vs CT groups and 25 paired in SI vs CT groups. Combined analysis of transcriptome and proteome demonstrated that PGC-1ß plays a important role in cancer energy metabolism and boosting the pace of chemical processes in the proliferation of breast cancer cells. Additional investigation about PGC-1ß and energy metabolism in cancer cells may shed fresh light on the growth and treatment of breast cancer cells.

The polymorphic CAG repeat in exon 1 of androgen receptor is associated with level of HDL cholesterol and hypertension in Chinese middle-aged and elderly men.

OBJECTIVE: The length of the CAG repeats in exon 1 of the androgen receptor (AR) gene has been shown to be inversely correlated with AR transcriptional activity. This study aimed to investigate the correlations between the length of CAG repeat in AR and serum lipids and hypertension in Chinese men. DESIGN AND PATIENTS: The relationship between length of the CAG repeat in exon 1 of AR with prevalence of hypertension and the levels of serum lipids among Chinese men (aged ≥40 years). MEASUREMENTS: The physical condition of the subjects was examined and recorded. The concentrations of blood lipids and sex hormones were measured, and the CAG repeat lengths of the AR gene were determined. RESULTS: The length of the AR CAG repeats was associated with HDL cholesterol (HDL-C) concentration, and the stepwise multiple regression model showed that this association was independent of body mass index (BMI), triglycerides (TG) and total cholesterol (TC), although these factors influence HDL-C concentration. Furthermore, men with <22 vs men with ≥22 CAG repeats showed higher blood pressure and higher prevalence of hypertension. Shorter CAG repeat numbers were associated with the increased risk of hypertension in a multivariate logistic regression analysis (odds ratio = 0·715; 95% confidence interval, 0·517-0·989; P = 0·043). No significant correlation of AR CAG repeat polymorphism with sex hormone levels, TG, LDL cholesterol (LDL-C) or TC was found. CONCLUSIONS: This study provides evidence that men carrying shorter (<22) AR CAG repeats have lower HDL-C level and increased risk of hypertension. The androgenic activity may differ due to the polymorphic length of CAG repeats of the AR gene.

The circular RNA hsa_circ_0045800 serves as a favorable biomarker in pathogenesis of sjögren's syndrome.

BACKGROUND: Circular RNAs (circRNAs) play various roles in the development of many autoimmune diseases. However, their expression profiles and specific function in Sjögren's Syndrome remains largely unknown. OBJECTIVES: We aimed to investigate circRNAs potential diagnostic value in primary Sjögren's syndrome (pSS) and contribution to the pathogenesis of pSS. METHODS: This study included 102 subjects, 51 pSS patients and 51 healthy controls. The concentration of hsa_circ_0045800 was analyzed in peripheral blood mononuclear cells obtained from 51 pSS patients and 51 healthy controls by qRT-PCR. We established a receiver operating characteristic curve (ROC) to assess the biological diagnostic value of hsa_circ_0045800 for pSS. In addition, we analyzed the correlation between hsa_circ_0045800 and disease activity in Sjogren's syndrome. A differential analysis was also conducted on the concentration of hsa_circ_0045800 in patients in pSS patients before and after treatment. We studied the downstream mechanism of hsa_circ_0045800 through bioinformatics analysis and confirmed it using luciferase reporter gene assay. RESULTS: We confirmed that the concentration of hsa_circ_0045800 was elevated 10.4-fold in peripheral blood mononuclear cells of pSS patients than in healthy controls (p = 0.00). In the pSS active disease group, the concentration of hsa_circ_0045800 is 2.5-fold higher compared to the pSS non-active disease group (p = 0.04). The concentration of hsa_circ_0045800 after treatment was decreased by 80% compared with that before treatment (p = 0.037), suggesting its utility as a potential marker for monitoring treatment efficacy. ROC curve analysis showed that the diagnostic value of hsa_circ_0045800 in pSS patients was significantly higher than that in healthy controls, with an area under the curve of 0.865, a sensitivity of 74%, and a specificity of 92%. The concentration of hsa_circ_0045800 is correlated with various clinical factors: the concentration of hsa_circ_0045800 is positively associated with age (r = 0.328, P = 0.019), oral dryness (r = 0.331, P = 0.017), while it is negatively correlated with HGB (r = -0.435, P = 0.001) and and hypothyroidism (r = -0.318, P = 0.023). Bioinformatics predictions and luciferase assays indicated that hsa_circ_0045800 acts as a molecular sponge for miR-1247-5p, with SMAD2 being a target gene of miR-1247-5p. CONCLUSION: Our study results show that hsa_circ_0045800 potentially contributes to the development and progression of pSS via the miR-1247-5p/SMAD2 pathway. Peripheral blood mononuclear cells are directly involved in the pathogenesis of pSS, and the discovery of hsa_circ_0045800 in peripheral blood mononuclear cells highlights its potential as a novel biomarker for disease activity and diagnosis in patients with pSS. Key Points • The concentration of hsa_circ_0045800 was higher in peripheral blood mononuclear cells of pSS patients. • Hsa_circ_0045800 promoted pSS progression through miR-1247-5p-SMAD2 axis. • Hsa_circ_0045800 is a potential biomarker for pSS.

RAF1 facilitates KIT signaling and serves as a potential treatment target for gastrointestinal stromal tumor.

The aberrant activation of RAS/RAF/MEK/ERK signaling is important for KIT mutation-mediated tumorigenesis of gastrointestinal stromal tumor (GIST). In this study, we found that inhibition of RAF1 suppresses the activation of both wild-type KIT and primary KIT mutations in GIST, with primary KIT mutations showing greater sensitivity. This suggests a positive feedback loop between KIT and RAF1, wherein RAF1 facilitates KIT signaling. We further demonstrated that RAF1 associates with KIT and the kinase activity of RAF1 is necessary for its contribution to KIT activation. Accordingly, inhibition of RAF1 suppressed cell survival, proliferation, and cell cycle progression in vitro mediated by both wild-type KIT and primary KIT mutations. Inhibition of RAF1 in vivo suppressed GIST growth in a transgenic mouse model carrying germline KIT/V558A mutation, showing a similar treatment efficiency as imatinib, the first-line targeted therapeutic drug of GIST, while the combination use of imatinib and RAF1 inhibitor further suppressed tumor growth. Acquisition of drug-resistant secondary mutation of KIT is a major cause of treatment failure of GIST following targeted therapy. Like wild-type KIT and primary KIT mutations, inhibition of RAF1 suppressed the activation of secondary KIT mutation, and the cell survival, proliferation, cell cycle progression in vitro, and tumor growth in vivo mediated by secondary KIT mutation. However, the activation of secondary KIT mutation is less dependent on RAF1 compared with that of primary KIT mutations. Taken together, our results revealed that RAF1 facilitates KIT signaling and KIT mutation-mediated tumorigenesis of GIST, providing a rationale for further investigation into the use of RAF1 inhibitors alone or in combination with KIT inhibitor in the treatment of GIST, particularly in cases resistant to KIT inhibitors.

Entry of ZSWIM4 to the nucleus is crucial for its inhibition of KIT and BMAL1 in gastrointestinal stromal tumors.

BACKGROUND: Zinc finger SWIM-type containing 4 (ZSWIM4) is a zinc finger protein with its function largely uncharacterized. In this study, we aimed to investigate the role of ZSWIM4 in gastrointestinal stromal tumors (GISTs). RESULTS: We found that ZSWIM4 expression is inhibited by the predominantly mutated protein KIT in GISTs, while conversely, ZSWIM4 inhibits KIT expression and downstream signaling. Consistent with the observation, ZSWIM4 inhibited GIST cell survival and proliferation in vitro. RNA sequencing of GISTs from KITV558A/WT mice and KITV558A/WT/ZSWIM4-/- mice showed that loss of ZSWIM4 expression increases the expression of circadian clock pathway member BMAL1 which contributes to GIST cell survival and proliferation. In addition, we found that KIT signaling increases the distribution of ZSWIM4 in the nucleus of GIST cells, and which is important for its inhibition of KIT and BMAL1. In agreement with the results in vitro, the in vivo studies showed that ZSWIM4 deficiency increases the tumorigenesis of GISTs in KITV558A/WT mice. CONCLUSIONS: Taken together, our results revealed that the entry of ZSWIM4 to the nucleus is important for its inhibition of KIT and BMAL1, ultimately attenuating GIST tumorigenesis. The results provide a novel insight in the understanding of signal transduction in GISTs and lay strong theoretical basis for the advancement of GIST treatment.

Farnesyltransferase (FTase) Inhibitors Increase Inhibition of KIT Mutants by Imatinib.

Background: Mutations in the receptor tyrosine kinase KIT are the major cause of gastrointestinal stromal tumors. KIT-mediated activation of the RAS/RAF/MEK/ERK and PI3 kinase/AKT pathways plays an important role in KIT mutant-mediated cell transformation. Methods: The frequently seen primary KIT mutations W557K558del and V560D, and the secondary KIT mutations V654A and N822K, in gastrointestinal stromal tumors were stably transfected into Ba/F3 cells. Cell proliferation was examined with a CCK kit, and cell survival and cell cycle were examined by flow cytometry. Cell signaling was examined by western blot. Results: We found that farnesyltransferase inhibitors tipifarnib and lonafarnib, which inhibit RAS activity, inhibited ERK activation mediated by both wild-type and KIT mutants, which often occur in gastrointestinal stromal tumors. Correspondingly, both wild-type and KIT mutant-mediated cell survival and proliferation were inhibited by both inhibitors. Imatinib is used as the first-line targeted therapy for gastrointestinal stromal tumors in the clinic. In our study, both inhibitors increased imatinib-mediated inhibition of cell survival and proliferation induced by both wild-type and KIT mutants. Similar to the primary KIT mutations, secondary mutations of KIT-induced ERK activation and cell response were inhibited by both inhibitors. Conclusions: Our results suggested the potential benefit of farnesyltransferase inhibitors either alone or combined with imatinib in the treatment of gastrointestinal stromal tumors carrying KIT mutations.

Hypermethylation of mitochondrial DNA facilitates bone metastasis of renal cell carcinoma.

Kidney cancers including clear cell carcinoma (RCC) are identified with very vulnerable mitochondria DNA (mtDNA) and frequent epigenetic aberrations. Bone metastasis from RCC is prevalent and destructive. Bone marrow contains a quite hypoxic microenvironment that usually insitigate 50% of hypermethylation events in conferring a selective advantage for tumor growth. We hypothesized that hypermethylation of mtDNA in RCC cells would significantly contribute to bone metastatic tumor progression. Methylation-specific polymerase chain reaction assay (MSP) was adopted to measure the methylation status of D-loop region of mtDNA in 15 pairs of bone metastatic and primary RCC as well as tumor adjescent normal kidney tissues. mtDNA copy number was examined by the real-time quantitative polymerase chain reaction (qPCR). Western blotting analysis was used to measure the accumulation of several DNA methyltransferases (DNMTs) in the mitochondria and nucleus fractions of bone metastatic RCC cells. mRNA expression of mitochondria encoded genes was examined by RT-PCR. Reactive oxygen species (ROS), mitochondrial membrane potential and ATP content were measured using in vitro cells treated with de-methylation drug 5-Azacytidine (5-Aza). Non-invasive bioluminescent imaging was performed to monitor tumor occurrence in skeleton in mice. Our results showed that the D-loop region in bone metastatic tumor cells was markedly hypermethylated than those in primary RCC tumor cells, that is associated with a decreased mtDNA copy number and accumulation of DNMT1 in the mitochondria. The bone-tropism tumor colonization and progression of RCC cells was significantly suppressed by demethylating the D-loop region of mtDNA and reducing the intracellular level of ROS and ATP by 5-Aza treatment. In conclusion, our study provided a direct association between hypermethylation of mtDNA in RCC with bone metastastic tumor growth.

Hsa_circ_0008301 as a potential biomarker of disease activity for primary Sjogren's syndrome: Increased expression in peripheral blood of patients with primary Sjogren's syndrome.

OBJECTIVES: To explore the expression level, association with disease activity and clinical significance of hsa_circ_0008301 in the peripheral blood of patients with primary Sjögren's syndrome (pSS). METHODS: We selected 70 pSS patients hospitalized under the Rheumatology service line at the General Hospital of Ningxia Medical University from September 2018 to June 2021 as the disease group, in which general data and clinical indicators were collected. Fifty-three patients with healthy physical examinations for the same period were selected as the healthy control group, and 32 patients with non-pSS rheumatic diseases were selected as the disease control group. We collected peripheral blood samples and used fluorescence quantitative PCR to detect the expression level of hsa_circ_0008301. In addition, we analyzed the association of the expression level of hsa_circ_0008301 with the clinical characteristics and disease activity of pSS patients. A receiver operating characteristic curve was used to evaluate the diagnosis and the disease activity value of hsa_circ_0008301 in patients with pSS. Meanwhile, we analyzed the differential expression of hsa_circ_0008301 in 24 pSS patients selected from the disease group before and after treatment. RESULTS: The relative expression of hsa_circ_0008301 in the peripheral blood of pSS patients was significantly higher than that in the control groups including healthy control group and disease control group. The expression level of hsa_circ_0008301 was high in pSS patients with a course of disease ≥ 10 years, fatigue symptoms, platelets < 100*10^9/L, erythrocyte sedimentation rate ≥ 50 mm/h, immunoglobulin IgG > 16 g/L, complement C3 < 0.9 g/L, ESSDAI score ≥ 5 and positively correlated with the above groups. Furthermore, ROC analysis showed that hsa_circ_0008301 was statistically significant between pSS patients and healthy controls. We selected patients from the disease group before and after treatment and showed that the expression level of hsa_circ_0008301 decreased significantly after treatment, compared with before. The area under the curve (AUC) was 0.825 (95% CI: 0.754 âˆ¼ 0.897; P < 0.0001). The AUC of hsa_circ_0008301 in pSS patients and the disease control group was 0.673 (95% CI: 0.563 âˆ¼ 0.782; P = 0.005), the sensitivity was 40.00%, the specificity was 93.70%, the optimal truncation value was > 0.0420, and the maximum Youden index was 0.337. In addition, ROC analysis revealed that hsa_circ_0008301 was statistically significant between disease-active patients and stable patients. The AUC value was 0.681 (95% CI: 0.553 âˆ¼ 0.809; P = 0.010), the sensitivity was 65.90%, the specificity was 72.40%, the optimal truncation value was > 0.0285, and the maximum Youden index was 0.383. ROC analysis indicated that hsa_circ_0008301 has some value in the diagnosis and disease activity of patients with pSS. Comparison of 24 pSS patients selected from the disease group before and after treatment showed that the expression level of hsa_circ_0008301 decreased significantly after treatment compared with before treatment (Z =  - 4.257, P < 0.0001). ROC analysis indicated that hsa_circ_0008301 has some value in the diagnosis and disease activity of patients with pSS. CONCLUSIONS: Hsa_circ_0008301 is expressed in higher levels in the peripheral blood of patients with pSS, which is related to the disease activity. It may be involved in the occurrence and development of pSS and may have a potential biomarker for the disease.

LncSNHG1 Promoted CRC Proliferation through the miR-181b-5p/SMAD2 Axis.

Objective: To investigate the effects of LncRNA SNHG1 on the proliferation, migration, and epithelial-mesenchymal transition (EMT) of colorectal cancer cells (CRCs). Methods: 4 pairs of CRC tissue samples and their corresponding adjacent samples were analyzed by the human LncRNA microarray chip. The expression of LncSNHG1 in CRC cell lines was verified by qRT-PCR. Colony formation assays and CCK8 assays were applied to study the changes in cell proliferation. The transwell assay and wound healing experiments were used to verify the cell invasion and migration. EMT progression was confirmed finally. Results: LncSNHG1 was overexpressed both in CRC tissues and cell lines, while the miR-181b-5p expression was decreased in CRC cell lines. After knock-down of LncSNHG1, the proliferation, invasion, and migration of HT29 and SW620 cells were all decreased. Meanwhile, LncSNHG1 enhanced EMT progress through regulation of the miR-181b-5p/SMAD2 axis. Conclusion: LncSNHG1 promotes colorectal cancer cell proliferation and invasion through the miR-181b-5p/SMAD2 axis.

The Role of Non-Coding RNAs in Breast Cancer Drug Resistance.

Breast cancer (BC) is one of the commonly occurring malignancies in females worldwide. Despite significant advances in therapeutics, the mortality and morbidity of BC still lead to low survival and poor prognosis due to the drug resistance. There are certain chemotherapeutic, endocrine, and target medicines often used for BC patients, including anthracyclines, taxanes, docetaxel, cisplatin, and fluorouracil. The drug resistance mechanisms of these medicines are complicated and have not been fully elucidated. It was reported that non-coding RNAs (ncRNAs), such as micro RNAs (miRNA), long-chain non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) performed key roles in regulating tumor development and mediating therapy resistance. However, the mechanism of these ncRNAs in BC chemotherapeutic, endocrine, and targeted drug resistance was different. This review aims to reveal the mechanism and potential functions of ncRNAs in BC drug resistance and to highlight the ncRNAs as a novel target for achieving improved treatment outcomes for BC patients.

Mortalin maintains breast cancer stem cells stemness via activation of Wnt/GSK3ß/ß-catenin signaling pathway.

Previous research indicated that mortalin overexpressed in breast cancer and contributed to carcinogenesis. Mortalin was also demonstrated to promote Epithelial-mesenchymal transition (EMT) and was considered as a factor for maintaining the stemness of the cancer stem cells. However, the underlying mechanisms about mortalin maintaining the stemness of breast cancer stem cells (BCSCs) remain unclear. Here, we identified that increased expression of mortalin in breast cancer was associated with poorer overall survival rate. Mortalin was elevated in breast cancer cell lines and BCSC-enriched populations. Additionally, knockdown of mortalin significantly inhibited the cell proliferation, migration and EMT, as well as sphere forming capacity and stemness genes expression. Further study revealed that mortalin promoted EMT and maintained BCSCs stemness via activating the Wnt/GSK3ß/ß-catenin signaling pathway in vivo and in vitro. Taken together, these findings unveiled the mechanism of mortalin in maintaining and regulating the stemness of BCSCs, and may offer novel therapeutic strategies for breast cancer treatment.

Homoharringtonine inhibited breast cancer cells growth via miR-18a-3p/AKT/mTOR signaling pathway.

Homoharringtonine (HHT), a natural alkaloid derived from the cephalotaxus, exhibited its anti-cancer effects in hematological malignancies clinically. However, its pesticide effects and mechanisms in treating solid tumors remain unclear. In this study, we found that HHT was capable of inhibiting tumor growth after 5-days treatment of breast cancer cells, MCF-7, in vivo. Furthemore, HHT also significantly inhibited the cancer cell growth and induced cell apoptosis in vitro. miRNA sequencing proved miR-18a-3p was noticeably downregulated in the cells after HHT treatment. Moreover, downregulating miR-18a-3p increased HHT-induced cell apoptosis; our data supported that HHT suppressed miR-18a-3p expression and inhibited tumorigenesis might via AKT-mTOR signaling pathway. In conclusion: our study proved that HHT suppressed breast cancer cell growth and promoted apoptosis mediated by regulating of the miR-18a-3p-AKT-mTOR signaling pathway, HHT may be a promising antitumor agent in breast cancer treatment.

[Over-expression of circNR4A1/Hsa-circ-0026352 inhibits proliferation and induces apoptosis in MCF-7 cells].

Objective To investigate the expression of circNR4A1/Hsa-circ-0026352 in breast tumor tissue, peripheral blood, cell lines and its effect on the proliferation and apoptosis of MCF-7 breast cancer cells. Methods Using circRNA microarray, different expression of human circRNAs was found out between the breast cancer tissues and adjacent normal tissues. The expression of circNR4A1 in breast cancer tissues, peripheral blood and breast cancer cell lines including MCF-7, HCC-1937, MDA-MB-231, T-47D and MCF-10A were detected by quantitative real-time PCR (qRT-PCR). Circular RNA interactome software and KEGG software were used to predict its target miRNA and bio-function. The circNR4A1 over-expression vector was constructed and transfected into MCF-7 cells. The effect of circNR4A1 on the proliferation of MCF-7 cells was detected by CCK-8 assay and clone formation assay. The cell apoptosis and cell cycle distribution were analyzed by flow cytometry and Hoechst 33258 stainning. The qRT-PCR was performed to detect the mRNA expression levels of MEK/ERK signal pathway genes (K-RAS, MEK, ERK) and apoptosis-related genes (Bcl2, BAX, BAD, caspase-3). Western blotting was used to detect the expression of MEK, ERK, Bcl2, BAD and caspase-3 proteins. Results The expression of circNR4A1(Hsa-circ-0026352) was lower in breast cancer tissues, peripheral blood and breast cancer cell lines than in adjacent normal tissues, healthy individuals' peripheral blood and human breast epithelial cells. Over-expression of circNR4A1 in MCF-7 cells inhibited the cell proliferation, promoted cell apoptosis and blocked the cell cycle in G1/S phase. The mRNA and protein expression of MEK, ERK, Bcl2 were significantly depressed, while the expression of BAD, caspase-3 were enhanced in the MCF-7 cells over-expressing circNR4A1. Conclusion The expression of circNR4A1/Hsa-circ-0026352 is lower in breast cancer tissues, peripheral blood and breast cancer cells. Over-expression of circNR4A1 can inhibit cell proliferation and induce cell apoptosis in MCF-7 cells.

Identification of Hsa_circ_0104824 as a Potential Biomarkers for Breast Cancer.

BACKGROUND: To study the specific expression of circular RNA (circRNA) in breast cancer and adjacent normal tissues to identify differentially expressed circRNA in breast cancer patients. To study the correlation between circRNA and clinical data of breast cancer, and to evaluate its potential as a breast cancer biomarker. METHODS: The differential expression of circRNAs between the breast cancer tissues and adjacent normal tissues was screened by Human CircRNA Microarray. Candidate circRNAs verified by qRT-PCR. CircRNA was analyzed by Agilent GeneSpring 13.0 software. SPSS23.0, GraphPad Prism, and Sigmaplot software were used for statistical analysis. Perform T test, one-way ANOVA, curve regression analysis and ROC curve analysis for evaluating the diagnostic value of circular RNA. RESULTS: Among the 2021 differentially expressed circRNAs, 546 were up-regulated and 1475 were down-regulated in breast cancer tissues. The validation study demonstrated that six circRNAs were downregulated. Among them, hsa_circ_0104824 proved high correlation between breast cancer tissues and plasma samples in its expression and diagnostic value. CONCLUSION: Hsa_circ_0104824 may serve as a promising predictive biomarker and therapeutic target for patients with breast cancer.

CircRNA hsa_circ_0004585 as a potential biomarker for colorectal cancer.

Objective: Circular RNAs (circRNAs) are involved in regulating of carcinogenesis of various cancer cells. However, the function of circRNAs in colorectal cancer (CRC) has remained largely unknown. This study investigated the characteristic expression of circRNAs in CRC and adjacent normal tissues, analyzed the miRNAs related to candidate circRNAs, and studied the correlation between circRNAs with clinical data of CRC. Methods: Human CircRNA microarray has been applied to screen the expressions of circRNAs of the CRC tissues and adjacent normal tissues. Quantitative real-time polymerase chain reaction (qRT-PCR) verified the candidate circRNAs in CRC tissue and patients' peripheral blood. The circRNA array data were analyzed by GeneSpring 13.0 (Agilent) software. The diseases, pathways and functional enrichment analysis of these genes were performed using the KEGG system. In addition, the circRNA-miRNA network was constructed based on the miRanda-3.3 software. Statistical analysis was performed with SPSS23.0, GraphPad Prism, and Sigmaplot software. Results: In total, 13,198 circRNAs were identified as distinct between CRC and adjacent normal tissues, including 6,697 upregulated and 6,501 downregulated genes. Based on scores, six of them were selected for further verification in CRC tissues and peripheral blood. The hsa_circ_0004585 expression was significantly upregulated both in CRC patients tissue and peripheral blood. Hsa_circ_0004585 was positively correlated with patient's tumor size, indicating the function of hsa_circ_0004585 in CRC carcinogenesis and metastasis. Conclusion: Hsa_circ_0004585 could be a potential biomarker for diagnosis of CRC.

Improved site-specific recombinase-based method to produce selectable marker- and vector-backbone-free transgenic cells.

PhiC31 integrase-mediated gene delivery has been extensively used in gene therapy and animal transgenesis. However, random integration events are observed in phiC31-mediated integration in different types of mammalian cells; as a result, the efficiencies of pseudo attP site integration and evaluation of site-specific integration are compromised. To improve this system, we used an attB-TK fusion gene as a negative selection marker, thereby eliminating random integration during phiC31-mediated transfection. We also excised the selection system and plasmid bacterial backbone by using two other site-specific recombinases, Cre and Dre. Thus, we generated clean transgenic bovine fetal fibroblast cells free of selectable marker and plasmid bacterial backbone. These clean cells were used as donor nuclei for somatic cell nuclear transfer (SCNT), indicating a similar developmental competence of SCNT embryos to that of non-transgenic cells. Therefore, the present gene delivery system facilitated the development of gene therapy and agricultural biotechnology.